Carbidopa And Levodopa

Carbidopa and levodopa extended-release tablet contains carbidopa and levodopa in a 1:4 ratio as either the 50 mg/200 mg tablet or the 25 mg/100 mg tablet. The daily dosage of carbidopa and levodopa extended-release tablets must be determined by careful titration. Patients should be monitored closely during the dose adjustment period, particularly with regard to appearance or worsening of involuntary movements, dyskinesias or nausea. Carbidopa and levodopa extended-release tablets should not be chewed or crushed.
Standard drugs for Parkinson's disease, other than levodopa without a decarboxylase inhibitor, may be used concomitantly while carbidopa and levodopa extended-release tablet is being administered, although their dosage may have to be adjusted.
Since carbidopa prevents the reversal of levodopa effects caused by pyridoxine, carbidopa and levodopa extended-release tablets can be given to patients receiving supplemental pyridoxine (vitamin B6).

Patients currently treated with conventional carbidopa and levodopa preparations:
Studies show that peripheral dopa-decarboxylase is saturated by the bioavailable carbidopa at doses of 70 mg a day and greater. Because the bioavailabilities of carbidopa and levodopa in carbidopa and levodopa tablets and carbidopa and levodopa extended-release tablets are different, appropriate adjustments should be made, as shown in Table 2.

Carbidopa and levodopa extended-release tablets
50 mg/200 mg

200

0.7 to 0.75†

140 to 150

Carbidopa and levodopa tablets
25 mg/100 mg

100

0.99‡

99

Dosage with carbidopa and levodopa extended-release tablets should be substituted at an amount that provides approximately 10% more levodopa per day, although this may need to be increased to a dosage that provides up to 30% more levodopa per day depending on clinical response (see DOSAGE AND ADMINISTRATION, Titration with carbidopa and levodopa extended-release tablets). The interval between doses of carbidopa and levodopa extended-release tablets should be 4 to 8 hours during the waking day. (See CLINICAL PHARMACOLOGY, Pharmacodynamics.)
A guideline for initiation of carbidopa and levodopa extended-release tablets is shown in Table 3.

Total Daily Dose*

Suggested

Levodopa (mg)

Dosage Regimen

300 to 400

200 mg b.i.d.

500 to 600

300 mg b.i.d.
or 200 mg t.i.d.

700 to 800

A total of 800 mg in 3 or more divided doses (e.g., 300 mg a.m., 300 mg early p.m., and 200 mg later p.m.)

900 to 1000

A total of 1000 mg in 3 or more divided doses (e.g., 400 mg a.m., 400 mg early p.m., and 200 mg later p.m.)

Patients currently treated with levodopa without a decarboxylase inhibitor:
Levodopa must be discontinued at least twelve hours before therapy with carbidopa and levodopa extended-release tablets is started. Carbidopa and levodopa extended-release tablets should be substituted at a dosage that will provide approximately 25% of the previous levodopa dosage. In patients with mild to moderate disease, the initial dose is usually 1 tablet of carbidopa and levodopa extended-release tablets 50 mg/200 mg b.i.d.
Patients not receiving levodopa:
In patients with mild to moderate disease, the initial recommended dose is 1 tablet of carbidopa and levodopa extended-release tablets 50 mg/200 mg b.i.d. Initial dosage should not be given at intervals of less than 6 hours.

Following initiation of therapy, doses and dosing intervals may be increased or decreased depending upon therapeutic response. Most patients have been adequately treated with doses of carbidopa and levodopa extended-release tablets that provide 400 to 1600 mg of levodopa per day, administered as divided doses at intervals ranging from 4 to 8 hours during the waking day. Higher doses of carbidopa and levodopa extended-release tablets (2400 mg or more of levodopa per day) and shorter intervals (less than 4 hours) have been used, but are not usually recommended.
When doses of carbidopa and levodopa extended-release tablets are given at intervals of less than 4 hours, and/or if the divided doses are not equal, it is recommended that the smaller doses be given at the end of the day.
An interval of at least 3 days between dosage adjustments is recommended.

Because Parkinson's disease is progressive, periodic clinical evaluations are recommended; adjustment of the dosage regimen of carbidopa and levodopa extended-release tablets may be required.

Anticholinergic agents, dopamine agonists, and amantadine can be given with carbidopa and levodopa extended-release tablets. Dosage adjustment of carbidopa and levodopa extended-release tablets may be necessary when these agents are added.

A dose of carbidopa and levodopa tablets  25 mg/100 mg or 10 mg/100 mg (one half or a whole tablet) can be added to the dosage regimen of carbidopa and levodopa extended-release tablets in selected patients with advanced disease who need additional immediate-release levodopa for a brief time during daytime hours.

Sporadic cases of a symptom complex resembling Neuroleptic Malignant Syndrome (NMS) have been associated with dose reductions and withdrawal of carbidopa and levodopa tablets or carbidopa and levodopa extended-release tablets.
Patients should be observed carefully if abrupt reduction or discontinuation of carbidopa and levodopa extended-release tablets is required, especially if the patient is receiving neuroleptics. (See WARNINGS).
If general anesthesia is required, carbidopa and levodopa extended-release tablets may be continued as long as the patient is permitted to take oral medication. If therapy is interrupted temporarily, the patient should be observed for symptoms resembling NMS, and the usual dosage should be administered as soon as the patient is able to take oral medication.

Carbidopa and levodopa extended-release tablets contain carbidopa and levodopa in a 1:4 ratio as the 50 mg/200 mg tablet. The daily dosage of carbidopa and levodopa extended-release tablets must be determined by careful titration. Patients should be monitored closely during the dose adjustment period, particularly with regard to appearance or worsening of involuntary movements, dyskinesias or nausea. Carbidopa and levodopa extended-release tablets 50 mg/200 mg may be administered as whole or as half-tablets which should not be chewed or crushed. Carbidopa and levodopa extended-release tablets 25 mg/100 mg may be used in combination with carbidopa and levodopa extended-release tablets 50 mg/200 mg to titrate to the optimum dosage, or as an alternative to the 50 mg/200 mg half-tablet.

Standard drugs for Parkinson’s disease, other than levodopa without a decarboxylase inhibitor, may be used concomitantly while carbidopa and levodopa extended-release tablets are being administered, although their dosage may have to be adjusted.

Since carbidopa prevents the reversal of levodopa effects caused by pyridoxine, carbidopa and levodopa extended-release tablets can be given to patients receiving supplemental pyridoxine (vitamin B6).

Patients Currently Treated With Conventional Carbidopa-Levodopa Preparations: Studies show that peripheral dopa-decarboxylase is saturated by the bioavailable carbidopa at doses of 70 mg a day and greater. Because the bioavailabilities of carbidopa and levodopa in carbidopa and levodopa tablets and carbidopa and levodopa extended-release tablets are different, appropriate adjustments should be made, as shown in Table II.

Dosage with carbidopa and levodopa extended-release tablets should be substituted at an amount that provides approximately 10% more levodopa per day, although this may need to be increased to a dosage that provides up to 30% more levodopa per day depending on clinical response (see DOSAGE AND ADMINISTRATION,Titration). The interval between doses of carbidopa and levodopa extended-release tablets should be 4-8 hours during the waking day (see CLINICAL PHARMACOLOGY, Pharmacodynamics).

A guideline for initiation of carbidopa and levodopa extended-release tablets is shown in Table III.

Levodopa must be discontinued at least twelve hours before therapy with carbidopa and levodopa extended-release tablets is started. Carbidopa and levodopa extended-release tablets should be substituted at a dosage that will provide approximately 25% of the previous levodopa dosage. In patients with mild to moderate disease, the initial dose is usually 1 tablet of carbidopa and levodopa extended-release tablets 50 mg/200 mg b.i.d.

In patients with mild to moderate disease, the initial recommended dose is 1 tablet of carbidopa and levodopa extended-release tablets 50 mg/200 mg b.i.d. Initial dosage should not be given at intervals of less than 6 hours.

Following initiation of therapy, doses and dosing intervals may be increased or decreased depending upon therapeutic response. Most patients have been adequately treated with doses of carbidopa and levodopa extended-release tablets that provide 400 to 1600 mg of levodopa per day, administered as divided doses at intervals ranging from 4 to 8 hours during the waking day. Higher doses of carbidopa and levodopa extended-release tablets (2400 mg or more of levodopa per day) and shorter intervals (less than 4 hours) have been used, but are not usually recommended.

When doses of carbidopa and levodopa extended-release tablets are given at intervals of less than 4 hours, and/or if the divided doses are not equal, it is recommended that the smaller doses be given at the end of the day.

An interval of at least 3 days between dosage adjustments is recommended.

Because Parkinson’s disease is progressive, periodic clinical evaluations are recommended; adjustment of the dosage regimen of carbidopa and levodopa extended-release tablets may be required.

Anticholinergic agents, dopamine agonists, and amantadine can be given with carbidopa and levodopa extended-release tablets. Dosage adjustment of carbidopa and levodopa extended-release tablets may be necessary when these agents are added.

A dose of carbidopa-levodopa 25 mg/100 mg or 10 mg/100 mg (one half or a whole tablet) can be added to the dosage regimen of carbidopa and levodopa extended-release tablets in selected patients with advanced disease who need additional immediate-release levodopa for a brief time during daytime hours.

Sporadic cases of a symptom complex resembling Neuroleptic Malignant Syndrome (NMS) have been associated with dose reductions and withdrawal of carbidopa and levodopa tablets or carbidopa and levodopa extended-release tablets.

Patients should be observed carefully if abrupt reduction or discontinuation of carbidopa and levodopa extended-release tablets is required, especially if the patient is receiving neuroleptics (see WARNINGS).

If general anesthesia is required, carbidopa and levodopa extended-release tablets may be continued as long as the patient is permitted to take oral medication. If therapy is interrupted temporarily, the patient should be observed for symptoms resembling NMS, and the usual dosage should be administered as soon as the patient is able to take oral medication.

Instructions for Use/Handling Carbidopa and Levodopa Orally Disintegrating Tablets

Just prior to administration, GENTLY remove the tablet from the bottle with dry hands. IMMEDIATELY place the carbidopa and levodopa orally disintegrating tablet on top of the tongue where it will dissolve in seconds, then swallow with saliva. Administration with liquid is not necessary.

The optimum daily dosage of carbidopa and levodopa orally disintegrating tablets must be determined by careful titration in each patient. Carbidopa and levodopa orally disintegrating tablet is available in a 1:4 ratio of carbidopa to levodopa (carbidopa and levodopa orally disintegrating tablets 25 mg/100 mg) as well as 1:10 ratio (carbidopa and levodopa orally disintegrating tablets 25 mg/250 mg and carbidopa and levodopa orally disintegrating tablets 10 mg/100 mg). Tablets of the two ratios may be given separately or combined as needed to provide the optimum dosage.

Studies show that peripheral dopa decarboxylase is saturated by carbidopa at approximately 70 to 100 mg a day. Patients receiving less than this amount of carbidopa are more likely to experience nausea and vomiting.

Usual Initial Dosage
Dosage is best initiated with one tablet of carbidopa and levodopa orally disintegrating tablets 25 mg/100 mg three times a day. This dosage schedule provides 75 mg of carbidopa per day. Dosage may be increased by one tablet every day or every other day, as necessary, until a dosage of eight tablets of carbidopa and levodopa orally disintegrating tablets 25 mg/100 mg a day is reached.

If carbidopa and levodopa orally disintegrating tablet 10 mg/100 mg is used, dosage may be initiated with one tablet three or four times a day. However, this will not provide an adequate amount of carbidopa for many patients. Dosage may be increased by one tablet every day or every other day until a total of eight tablets (2 tablets q.i.d.) is reached.

How to Transfer Patients from Levodopa
Levodopa must be discontinued at least twelve hours before starting carbidopa and levodopa orally disintegrating tablets. A daily dosage of carbidopa and levodopa orally disintegrating tablets should be chosen that will provide approximately 25 percent of the previous levodopa dosage. Patients who are taking less than 1500 mg of levodopa a day should be started on one tablet of carbidopa and levodopa orally disintegrating tablets 25 mg/100 mg three or four times a day. The suggested starting dosage for most patients taking more than 1500 mg of levodopa is one tablet of carbidopa and levodopa orally disintegrating tablets 25 mg/250 mg three or four times a day.

The optimum daily dosage of carbidopa and levodopa must be determined by careful titration in each patient. Carbidopa and levodopa tablets are available in a 1:4 ratio of carbidopa to levodopa (carbidopa and levodopa tablets 25 mg/100 mg) as well as 1:10 ratio (carbidopa and levodopa tablets 25 mg/250 mg and carbidopa and levodopa tablets 10 mg/100 mg). Tablets of the two ratios may be given separately or combined as needed to provide the optimum dosage.

Studies show that peripheral dopa decarboxylase is saturated by carbidopa at approximately 70 to 100 mg a day. Patients receiving less than this amount of carbidopa are more likely to experience nausea and vomiting.

Dosage is best initiated with one tablet of carbidopa and levodopa 25 mg/100 mg three times a day. This dosage schedule provides 75 mg of carbidopa per day. Dosage may be increased by one tablet every day or every other day, as necessary, until a dosage of eight tablets of carbidopa and levodopa 25 mg/100 mg a day is reached.
 If carbidopa and levodopa tablets 10 mg/100 mg are used, dosage may be initiated with one tablet three or four times a day. However, this will not provide an adequate amount of carbidopa for many patients. Dosage may be increased by one tablet every day or every other day until a total of eight tablets (2 tablets q.i.d.) is reached.

Levodopa must be discontinued at least twelve hours before starting carbidopa and levodopa tablets.A daily dosage of carbidopa and levodopa should be chosen that will provide approximately 25% of the previous levodopa dosage. Patients who are taking less than 1,500 mg of levodopa a day should be started on one tablet of carbidopa and levodopa 25 mg/100 mg three or four times a day. The suggested starting dosage for most patients taking more than 1,500 mg of levodopa is one tablet of carbidopa and levodopa 25 mg/250 mg three or four times a day.

Therapy should be individualized and adjusted according to the desired therapeutic response. At least 70 to 100 mg of carbidopa per day should be provided. When a greater proportion of carbidopa is required, one tablet of carbidopa and levodopa 25 mg/100 mg may be substituted for each tablet of carbidopa and levodopa 10 mg/100 mg. When more levodopa is required, carbidopa and levodopa tablets 25 mg/250 mg should be substituted for carbidopa and levodopa tablets 25 mg/100 mg or carbidopa and levodopa tablets 10 mg/100 mg. If necessary, the dosage of carbidopa and levodopa tablets 25 mg/250 mg may be increased by one-half or one tablet every day or every other day to a maximum of eight tablets a day. Experience with total daily dosages of carbidopa greater than 200 mg is limited.

Because both therapeutic and adverse responses occur more rapidly with carbidopa and levodopa than with levodopa alone, patients should be monitored closely during the dose adjustment period. Specifically, involuntary movements will occur more rapidly with carbidopa and levodopa than with levodopa. The occurrence of involuntary movements may require dosage reduction. Blepharospasm may be a useful early sign of excess dosage in some patients.

Standard drugs for Parkinson's disease, other than levodopa without a decarboxylase inhibitor, may be used concomitantly while carbidopa and levodopa tablets are being administered, although dosage adjustments may be required.

Sporadic cases of hyperpyrexia and confusion have been associated with dose reductions and withdrawal of carbidopa and levodopa tablets. Patients should be observed carefully if abrupt reduction or discontinuation of carbidopa and levodopa tablets is required, especially if the patient is receiving neuroleptics. (See WARNINGS.)

If general anesthesia is required, carbidopa and levodopa may be continued as long as the patient is permitted to take fluids and medication by mouth. If therapy is interrupted temporarily, the patient should be observed for symptoms resembling NMS, and the usual daily dosage may be administered as soon as the patient is able to take oral medication.

Carbidopa and levodopa extended release tablets contain carbidopa and levodopa in a 1:4 ratio as either the 50 mg/200 mg tablet or the 25 mg/100 mg tablet. The daily dosage of carbidopa and levodopa extended release tablets must be determined by careful titration. Patients should be monitored closely during the dose adjustment period, particularly with regard to appearance or worsening of involuntary movements, dyskinesias or nausea. Carbidopa and levodopa extended release tablets 50 mg/200 mg may be administered as whole or as half-tablets which should not be chewed or crushed. Carbidopa and levodopa extended release tablets 25 mg/100 mg may be used in combination with carbidopa and levodopa extended release tablets 50 mg/200 mg to titrate to the optimum dosage, or as an alternative to the 50 mg/200 mg half-tablet.

Standard drugs for Parkinson’s disease, other than levodopa without a decarboxylase inhibitor, may be used concomitantly while carbidopa and levodopa extended release tablet is being administered, although their dosage may have to be adjusted.

Since carbidopa prevents the reversal of levodopa effects caused by pyridoxine, carbidopa and levodopa extended release tablets can be given to patients receiving supplemental pyridoxine (vitamin B6).

Patients currently treated with conventional carbidopa and levodopa preparations: Studies show that peripheral dopa-decarboxylase is saturated by the bioavailable carbidopa at doses of 70 mg a day and greater. Because the bioavailabilities of carbidopa and levodopa in carbidopa and levodopa tablets and carbidopa and levodopa extended release tablets are different, appropriate adjustments should be made, as shown in Table II.

Dosage with carbidopa and levodopa extended release tablets should be substituted at an amount that provides approximately 10% more levodopa per day, although this may need to be increased to a dosage that provides up to 30% more levodopa per day depending on clinical response (see DOSAGE AND ADMINISTRATION, Titration). The interval between doses of carbidopa and levodopa extended release tablets should be 4-8 hours during the waking day (See CLINICAL PHARMACOLOGY, Pharmacodynamics).

A guideline for initiation of carbidopa and levodopa extended release tablets is shown in Table III.

Levodopa must be discontinued at least twelve hours before therapy with carbidopa and levodopa extended release tablets is started. Carbidopa and levodopa extended release tablets should be substituted at a dosage that will provide approximately 25% of the previous levodopa dosage. In patients with mild to moderate disease, the initial dose is usually 1 tablet of carbidopa and levodopa extended release tablets 50 mg/200 mg b.i.d.

In patients with mild to moderate disease, the initial recommended dose is 1 tablet of carbidopa and levodopa extended release tablets 50 mg/200 mg b.i.d. Initial dosage should not be given at intervals of less than 6 hours.

Following initiation of therapy, doses and dosing intervals may be increased or decreased depending upon therapeutic response. Most patients have been adequately treated with doses of carbidopa and levodopa extended release tablets that provide 400 to 1600 mg of levodopa per day, administered as divided doses at intervals ranging from 4 to 8 hours during the waking day. Higher doses of carbidopa and levodopa extended release tablets (2400 mg or more of levodopa per day) and shorter intervals (less than 4 hours) have been used, but are not usually recommended.

When doses of carbidopa and levodopa extended release tablets are given at intervals of less than 4 hours, and/or if the divided doses are not equal, it is recommended that the smaller doses be given at the end of the day.

An interval of at least 3 days between dosage adjustments is recommended.

Because Parkinson’s disease is progressive, periodic clinical evaluations are recommended; adjustment of the dosage regimen of carbidopa and levodopa extended release tablets may be required.

Anticholinergic agents, dopamine agonists, and amantadine can be given with carbidopa and levodopa extended release tablets. Dosage adjustment of carbidopa and levodopa extended release tablets may be necessary when these agents are added.

A dose of carbidopa and levodopa tablets 25 mg/100 mg or 10 mg/100 mg (one half or a whole tablet) can be added to the dosage regimen of carbidopa and levodopa extended release tablets in selected patients with advanced disease who need additional immediate-release levodopa for a brief time during daytime hours.

Sporadic cases of a symptom complex resembling Neuroleptic Malignant Syndrome (NMS) have been associated with dose reductions and withdrawal of carbidopa and levodopa tablets or carbidopa and levodopa extended release tablets.

Patients should be observed carefully if abrupt reduction or discontinuation of carbidopa and levodopa extended release tablets is required, especially if the patient is receiving neuroleptics (See WARNINGS).

If general anesthesia is required, carbidopa and levodopa extended release tablets may be continued as long as the patient is permitted to take oral medication. If therapy is interrupted temporarily, the patient should be observed for symptoms resembling NMS, and the usual dosage should be administered as soon as the patient is able to take oral medication.

The optimum daily dosage of carbidopa and levodopa tablets must be determined by careful titration in each patient.

Carbidopa and levodopa tablets are available in a 1:4 ratio of carbidopa to levodopa (carbidopa and levodopa tablets, USP 25 mg/100 mg) as well as 1:10 ratio (carbidopa and levodopa tablets, USP 25 mg/250 mg and carbidopa and levodopa lablets, USP 10 mg/100 mg). Tablets of the two ratios may be given separately or combined as needed to provide the optimum dosage.

Studies show that peripheral dopa decarboxylase is saturated by carbidopa at approximately 70 to 100 mg a day. Patients receiving less than this amount of carbidopa are more likely to experience nausea and vomiting.

Dosage is best initiated with one tablet of carbidopa and levodopa 25 mg/100 mg three times a day. This dosage schedule provides 75 mg of carbidopa per day. Dosage may be increased by one tablet every day or every other day, as necessary, until a dosage of eight tablets of carbidopa and levodopa 25 mg/100 mg a day is reached.

If carbidopa and levodopa tablets10 mg/100 mg is used, dosage may be initiated with one tablet three or four times a day.

However, this will not provide an adequate amount of carbidopa for many patients. Dosage may be increased by one tablet every day or every other day until a total of eight tablets (2 tablets q.i.d.) is reached.

Levodopa must be discontinued at least twelve hours before starting carbidopa and levodopa tablets. A daily dosage of carbidopa and levodopa tablets should be chosen that will provide approximately 25 percent of the previous levodopa dosage. Patients who are taking less than 1500 mg of levodopa a day should be started on one tablet of carbidopa and levodopa 25 mg/100 mg three or four times a day. The suggested starting dosage for most patients taking more than 1500 mg of levodopa is one tablet of carbidopa and levodopa 25 mg/250 mg three or four times a day

Therapy should be individualized and adjusted according to the desired therapeutic response. At least 70 to 100 mg of carbidopa per day should be provided. When a greater proportion of carbidopa is required, one tablet of carbidopa and levodopa 25 mg/100 mg may be substituted for each tablet of carbidopa and levodopa 10 mg/100 mg. When more levodopa is required, carbidopa and levodopa 25 mg/250 mg should be substituted for carbidopa and levodopa 25 mg/100 mg or carbidopa and levodopa 10 mg/100 mg. If necessary, the dosage of carbidopa and levodopa 25 mg/250 mg may be increased by one-half or one tablet every day or every other day to a maximum of eight tablets a day. Experience with total daily dosages of carbidopa greater than 200 mg is limited.

Because both therapeutic and adverse responses occur more rapidly with carbidopa and levodopa tablets than with levodopa alone, patients should be monitored closely during the dose adjustment period. Specifically, involuntary movements will occur more rapidly with carbidopa and levodopa tablets than with levodopa. The occurrence of involuntary movements may require dosage reduction. Blepharospasm may be a useful early sign of excess dosage in some patients.

Standard drugs for Parkinson's disease, other than levodopa without a decarboxylase inhibitor, may be used concomitantly while carbidopa and levodopa tablets are being administered, although dosage adjustments may be required.

Sporadic cases of a symptom complex resembling Neuroleptic Malignant Syndrome (NMS) have been associated with dose reductions and withdrawal of carbidopa and levodopa tablets. Patients should be observed carefully if abrupt reduction or discontinuation of carbidopa and levodopa tablets is required, especially if the patient is receiving neuroleptics. (See WARNINGS.)

If general anesthesia is required, carbidopa and levodopa tablets may be continued as long as the patient is permitted to take fluids and medication by mouth.

If therapy is interrupted temporarily, the patient should be observed for symptoms resembling NMS, and the usual daily dosage may be administered as soon as the patient is able to take oral medication.

The optimum daily dosage of carbidopa and levodopa tablets must be determined by careful titration in each patient. Carbidopa and levodopa tablets are available in a 1:4 ratio of carbidopa to levodopa (carbidopa and levodopa tablets 25 mg/100 mg) as well as 1:10 ratio (carbidopa and levodopa tablets 25 mg/250 mg and carbidopa and levodopa tablets 10 mg/100 mg). Tablets of the two ratios may be given separately or combined as needed to provide the optimum dosage.

Studies show that peripheral dopa decarboxylase is saturated by carbidopa at approximately 70 mg to 100 mg a day. Patients receiving less than this amount of carbidopa are more likely to experience nausea and vomiting.

Dosage is best initiated with one tablet of carbidopa and levodopa 25 mg/100 mg 3 times a day. This dosage schedule provides 75 mg of carbidopa per day. Dosage may be increased by one tablet every day or every other day, as necessary, until a dosage of eight tablets of carbidopa and levodopa 25 mg/100 mg a day is reached.

If carbidopa and levodopa 10 mg/100 mg is used, dosage may be initiated with one tablet 3 or 4 times a day. However, this will not provide an adequate amount of carbidopa for many patients. Dosage may be increased by one tablet every day or every other day until a total of eight tablets (two tablets q.i.d.) is reached.

Levodopa must be discontinued at least 12 hours before starting carbidopa and levodopa tablets. A daily dosage of carbidopa and levodopa should be chosen that will provide approximately 25% of the previous levodopa dosage. Patients who are taking less than 1500 mg of levodopa a day should be started on one tablet of carbidopa and levodopa 25 mg/100 mg 3 or 4 times a day. The suggested starting dosage for most patients taking more than 1500 mg of levodopa is one tablet of carbidopa and levodopa 25 mg/250 mg 3 or 4 times a day.

Therapy should be individualized and adjusted according to the desired therapeutic response. At least 70 mg to 100 mg of carbidopa per day should be provided. When a greater proportion of carbidopa is required, one tablet of carbidopa and levodopa 25 mg/100 mg may be substituted for each tablet of carbidopa and levodopa 10 mg/100 mg. When more levodopa is required, carbidopa and levodopa 25 mg/250 mg should be substituted for carbidopa and levodopa 25 mg/100 mg or carbidopa and levodopa 10 mg/100 mg. If necessary, the dosage of carbidopa and levodopa 25 mg/250 mg may be increased by one-half or one tablet every day or every other day to a maximum of eight tablets a day. Experience with total daily dosages of carbidopa greater than 200 mg is limited.

Because both therapeutic and adverse responses occur more rapidly with carbidopa and levodopa than with levodopa alone, patients should be monitored closely during the dose adjustment period. Specifically, involuntary movements will occur more rapidly with carbidopa and levodopa than with levodopa. The occurrence of involuntary movements may require dosage reduction. Blepharospasm may be a useful early sign of excess dosage in some patients.

Standard drugs for Parkinson's disease, other than levodopa without a decarboxylase inhibitor, may be used concomitantly while carbidopa and levodopa tablets are being administered, although dosage adjustments may be required.

Sporadic cases of a symptom complex resembling Neuroleptic Malignant Syndrome (NMS) have been associated with dose reductions and withdrawal of carbidopa and levodopa. Patients should be observed carefully if abrupt reduction or discontinuation of carbidopa and levodopa is required, especially if the patient is receiving neuroleptics. (See WARNINGS.)

If general anesthesia is required, carbidopa and levodopa tablets may be continued as long as the patient is permitted to take fluids and medication by mouth. If therapy is interrupted temporarily, the patient should be observed for symptoms resembling NMS and the usual daily dosage may be administered as soon as the patient is able to take oral medication.

Carbidopa-levodopa extended-release tablet contains carbidopa and levodopa in a 1:4 ratio as either the 50 mg/200 mg tablet or the 25 mg/100 mg tablet. The daily dosage of carbidopa-levodopa extended-release tablet must be determined by careful titration. Patients should be monitored closely during the dose adjustment period, particularly with regard to appearance or worsening of involuntary movements, dyskinesias or nausea. Carbidopa-levodopa extended-release tablet, 50 mg/200 mg may be administered as whole or as half-tablets which should not be chewed or crushed. Carbidopa-levodopa extended-release tablet 25 mg/100 mg may be used in combination with carbidopa-levodopa extended-release tablet 50 mg/200 mg to titrate to the optimum dosage, or as an alternative to the 50 mg/200 mg half-tablet.

Standard drugs for Parkinson's disease, other than levodopa without a decarboxylase inhibitor, may be used concomitantly while carbidopa-levodopa extendedrelease tablet is being administered, although their dosage may have to be adjusted.

Since carbidopa prevents the reversal of levodopa effects caused by pyridoxine, carbidopa-levodopa extended-release tablet can be given to patients receiving supplemental pyridoxine (vitamin B6).

Studies show that peripheral dopa-decarboxylase is saturated by the bioavailable carbidopa at doses of 70 mg a day and greater. Because the bioavailabilities of carbidopa and levodopa in carbidopa-levodopa tablets and carbidopa-levodopa extended-release tablet are different, appropriate adjustments should be made, as shown in Table II.

Dosage with carbidopa-levodopa extended-release tablet should be substituted at an amount that provides approximately 10% more levodopa per day, although this may need to be increased to a dosage that provides up to 30% more levodopa per day depending on clinical response (see DOSAGE AND ADMINISTRATION: Titration with carbidopa and levodopa extended-release tablet). The interval between doses of carbidopa-levodopa extended-release tablet should be 4-8 hours during the waking day. (See CLINICAL PHARMACOLOGY: Pharmacodynamics.)

A guideline for initiation of carbidopa-levodopa extended-release tablet is shown in Table III.

Levodopa must be discontinued at least twelve hours before therapy with carbidopa-levodopa extended-release tablet is started. Carbidopa-levodopa extended-release tablet should be substituted at a dosage that will provide approximately 25% of the previous levodopa dosage. In patients with mild to moderate disease, the initial dose is usually 1 tablet of carbidopa-levodopa extended-release tablet 50 mg/200 mg b.i.d.

In patients with mild to moderate disease, the initial recommended dose is 1 tablet of carbidopa-levodopa extended-release tablet 50 mg/200 mg b.i.d. Initial dosage should not be given at intervals of less than 6 hours.

Following initiation of therapy, doses and dosing intervals may be increased or decreased depending upon therapeutic response. Most patients have been adequately treated with doses of carbidopa-levodopa extended-release tablet that provide 400 to 1600 mg of levodopa per day, administered as divided doses at intervals ranging from 4 to 8 hours during the waking day. Higher doses of carbidopa-levodopa extended-release tablet (2400 mg or more of levodopa per day) and shorter intervals (less than 4 hours) have been used, but are not usually recommended.

When doses of carbidopa-levodopa extended-release tablet are given at intervals of less than 4 hours, and/or if the divided doses are not equal, it is recommended that the smaller doses be given at the end of the day.

An interval of at least 3 days between dosage adjustments is recommended.

Because Parkinson's disease is progressive, periodic clinical evaluations are recommended; adjustment of the dosage regimen of carbidopa-levodopa extended release tablet may be required.

Anticholinergic agents, dopamine agonists, and amantadine can be given with carbidopa-levodopa extended-release tablet. Dosage adjustment of carbidopa-levodopa extended-release tablet may be necessary when these agents are added.

A dose of carbidopa-levodopa tablets, 25 mg/100 mg or 10 mg/100 mg (one half or a whole tablet) can be added to the dosage regimen of carbidopa-levodopa extended-release tablet in selected patients with advanced disease who need additional immediate-release levodopa for a brief time during daytime hours.

Sporadic cases of a symptom complex resembling Neuroleptic Malignant Syndrome (NMS) have been associated with dose reductions and withdrawal of carbidopa-levodopa tablets or carbidopa-levodopa extended-release tablets.

Patients should be observed carefully if abrupt reduction or discontinuation of carbidopa-levodopa extended-release tablet is required, especially if the patient is receiving neuroleptics. (See WARNINGS.)

If general anesthesia is required, carbidopa-levodopa extended-release tablet may be continued as long as the patient is permitted to take oral medication. If therapy is interrupted temporarily, the patient should be observed for symptoms resembling NMS, and the usual dosage should be administered as soon as the patient is able to take oral medication.

The optimum daily dosage of carbidopa and levodopa tablets USP must be determined by careful titration in each patient. Carbidopa and levodopa tablets USP are available in a 1:4 ratio of carbidopa to levodopa (25 mg/100 mg) as well as a 1:10 ratio (25 mg/250 mg and 10 mg/100 mg). Tablets of the two ratios may be given separately or combined as needed to provide the optimum dosage.

Studies show that peripheral dopa decarboxylase is saturated by carbidopa at approximately 70 to 100 mg a day. Patients receiving less than this amount of carbidopa are more likely to experience nausea and vomiting.

Dosage is best initiated with one carbidopa and levodopa tablet USP, 25 mg/100 mg three times a day. This dosage schedule provides 75 mg of carbidopa per day. Dosage may be increased by one tablet every day or every other day, as necessary, until a dosage of eight carbidopa and levodopa tablets USP, 25 mg/100 mg a day is reached.

If carbidopa and levodopa tablets USP, 10 mg/100 mg are used, dosage may be initiated with one tablet three or four times a day. However, this will not provide an adequate amount of carbidopa for many patients. Dosage may be increased by one tablet every day or every other day until a total of eight tablets (2 tablets q.i.d.) is reached.

Levodopa must be discontinued at least twelve hours before starting this combination product. A daily dosage of carbidopa and levodopa tablets USP should be chosen that will provide approximately 25% of the previous levodopa dosage. Patients who are taking less than 1500 mg of levodopa a day should be started on one carbidopa and levodopa tablet USP, 25 mg/100 mg three or four times a day. The suggested starting dosage for most patients taking more than 1500 mg of levodopa is one carbidopa and levodopa tablet USP, 25 mg/250 mg three or four times a day.

Therapy should be individualized and adjusted according to the desired therapeutic response. At least 70 to 100 mg of carbidopa per day should be provided. When a greater proportion of carbidopa is required, one carbidopa and levodopa tablet USP, 25 mg/100 mg may be substituted for each carbidopa and levodopa tablet USP, 10 mg/100 mg. When more levodopa is required, each carbidopa and levodopa tablet USP, 25 mg/250 mg should be substituted for a carbidopa and levodopa tablet USP, 25 mg/100 mg or a carbidopa and levodopa tablet USP, 10 mg/100 mg. If necessary, the dosage of carbidopa and levodopa tablets USP, 25 mg/250 mg may be increased by one-half or one tablet every day or every other day to a maximum of eight tablets a day. Experience with total daily dosages of carbidopa greater than 200 mg is limited.

Because both therapeutic and adverse responses occur more rapidly with this combination product than with levodopa alone, patients should be monitored closely during the dose adjustment period. Specifically, involuntary movements will occur more rapidly with carbidopa and levodopa than with levodopa. The occurrence of involuntary movements may require dosage reduction. Blepharospasm may be a useful early sign of excess dosage in some patients.

Standard drugs for Parkinson’s disease, other than levodopa without a decarboxylase inhibitor, may be used concomitantly while carbidopa and levodopa therapy is being administered, although dosage adjustments may be required.

Sporadic cases of a symptom complex resembling Neuroleptic Malignant Syndrome (NMS) have been associated with dose reductions and withdrawal of carbidopa and levodopa tablets USP. Patients should be observed carefully if abrupt reduction or discontinuation of carbidopa and levodopa tablets USP is required, especially if the patient is receiving neuroleptics (see WARNINGS).

If general anesthesia is required, carbidopa and levodopa therapy may be continued as long as the patient is permitted to take fluids and medication by mouth. If therapy is interrupted temporarily, the patient should be observed for symptoms resembling NMS, and the usual daily dosage may be administered as soon as the patient is able to take oral medication.

The optimum daily dosage of carbidopa and levodopa must be determined by careful titration in each patient. Carbidopa and levodopa tablets are available in a 1:4 ratio of carbidopa to levodopa (25 mg/100 mg) as well as 1:10 ratio (25 mg/250 mg and 10 mg/100 mg). Tablets of the two ratios may be given separately or combined as needed to provide the optimum dosage.

Studies show that peripheral dopa decarboxylase is saturated by carbidopa at approximately 70 to 100 mg a day. Patients receiving less than this amount of carbidopa are more likely to experience nausea and vomiting.

Usual Initial Dosage: Dosage is best initiated with one tablet of carbidopa and levodopa 25 mg/100 mg three times a day. This dosage schedule provides 75 mg of carbidopa per day. Dosage may be increased by one tablet every day or every other day, as necessary, until a dosage of eight tablets of carbidopa and levodopa 25 mg/100 mg a day is reached.

If carbidopa and levodopa 10 mg/100 mg is used, dosage may be initiated with one tablet three or four times a day. However, this will not provide an adequate amount of carbidopa for many patients. Dosage may be increased by one tablet every day or every other day until a total of eight tablets (2 tablets q.i.d.) is reached.

How To Transfer Patients From Levodopa: Levodopa must be discontinued at leasttwelve hours before starting this combination product. A daily dosage of carbidopa and levodopa should be chosen that will provide approximately 25% of the previous levodopa dosage. Patients who are taking less than 1500 mg of levodopa a day should be started on one tablet of carbidopa and levodopa 25 mg/100 mg three or four times a day. The suggested starting dosage for most patients taking more than 1500 mg of levodopa is one tablet of carbidopa and levodopa 25 mg/250 mg three or four times a day.

Maintenance: Therapy should be individualized and adjusted according to the desired therapeutic response. At least 70 to 100 mg of carbidopa per day should be provided. When a greater proportion of carbidopa is required, one 25 mg/100 mg tablet may be substituted for each 10 mg/100 mg tablet. When more levodopa is required, each 25 mg/250 mg tablet should be substituted for a 25 mg/100 mg tablet or a 10 mg/100 mg tablet. If necessary, the dosage of carbidopa and levodopa 25 mg/250 mg may be increased by one-half or one tablet every day or every other day to a maximum of eight tablets a day. Experience with total daily dosages of carbidopa greater than 200 mg is limited.

Because both therapeutic and adverse responses occur more rapidly with this combination product than with levodopa alone, patients should be monitored closely during the dose adjustment period. Specifically, involuntary movements will occur more rapidly with carbidopa and levodopa than with levodopa. The occurrence of involuntary movements may require dosage reduction. Blepharospasm may be a useful early sign of excess dosage in some patients.

Addition Of Other Antiparkinsonian Medications: Standard drugs for Parkinson's disease, other than levodopa without a decarboxylase inhibitor, may be used concomitantly while carbidopa and levodopa is being administered, although dosage adjustments may be required.

Interruption Of Therapy: Sporadic cases of a symptom complex resembling Neuroleptic Malignant Syndrome (NMS) have been associated with dose reductions and withdrawal of carbidopa and levodopa. Patients should be observed carefully if abrupt reduction or discontinuation of carbidopa and levodopa is required, especially if the patient is receiving neuroleptics. (See WARNINGS.)

If general anesthesia is required, carbidopa and levodopa may be continued as long as the patient is permitted to take fluids and medication by mouth. If therapy is interrupted temporarily, the patient should be observed for symptoms resembling NMS, and the usual daily dosage may be administered as soon as the patient is able to take oral medication.

Carbidopa and levodopa extended-release tablets contain carbidopa and levodopa in a 1:4 ratio as either the 50 mg/200 mg tablet or the 25 mg/100 mg tablet. The daily dosage of carbidopa and levodopa extended-release tablets must be determined by careful titration. Patients should be monitored closely during the dose adjustment period, particularly with regard to appearance or worsening of involuntary movements, dyskinesias or nausea. Carbidopa and levodopa extended-release tablets should not be chewed or crushed.

Standard drugs for Parkinson’s disease, other than levodopa without a decarboxylase inhibitor, may be used concomitantly while carbidopa and levodopa extended-release tablets are being administered, although their dosage may have to be adjusted.

Since carbidopa prevents the reversal of levodopa effects caused by pyridoxine, carbidopa and levodopa extended-release tablets can be given to patients receiving supplemental pyridoxine (vitamin B6).

Studies show that peripheral dopa-decarboxylase is saturated by the bioavailable carbidopa at doses of 70 mg a day and greater. Because the bioavailabilities of carbidopa and levodopa in carbidopa and levodopa immediate-release tablets and carbidopa and levodopa extended-release tablets are different, appropriate adjustments should be made, as shown in Table 2.

Dosage with carbidopa and levodopa extended-release tablets should be substituted at an amount that provides approximately 10% more levodopa per day, although this may need to be increased to a dosage that provides up to 30% more levodopa per day depending on clinical response (see DOSAGE AND ADMINISTRATION: Titration with Carbidopa and Levodopa Extended-release Tablets). The interval between doses of carbidopa and levodopa extended-release tablets should be 4 to 8 hours during the waking day (see CLINICAL PHARMACOLOGY: Pharmacodynamics).

A guideline for initiation of carbidopa and levodopa extended-release tablets is shown in Table 3.

Levodopa must be discontinued at least 12 hours before therapy with carbidopa and levodopa extended-release tablets is started. Carbidopa and levodopa extended-release tablets should be substituted at a dosage that will provide approximately 25% of the previous levodopa dosage. In patients with mild to moderate disease, the initial dose is usually one tablet of 50 mg/200 mg carbidopa and levodopa extended-release tablets b.i.d.

In patients with mild to moderate disease, the initial recommended dose is one tablet of 50 mg/200 mg carbidopa and levodopa extended-release tablets b.i.d. Initial dosage should not be given at intervals of less than 6 hours.

Following initiation of therapy, doses and dosing intervals may be increased or decreased depending upon therapeutic response. Most patients have been adequately treated with doses of carbidopa and levodopa extended-release tablets that provide 400 mg to 1600 mg of levodopa per day, administered as divided doses at intervals ranging from 4 to 8 hours during the waking day. Higher doses of carbidopa and levodopa extended-release tablets (2400 mg or more of levodopa per day) and shorter intervals (less than 4 hours) have been used, but are not usually recommended.

When doses of carbidopa and levodopa extended-release tablets are given at intervals of less than 4 hours, and/or if the divided doses are not equal, it is recommended that the smaller doses be given at the end of the day.

An interval of at least 3 days between dosage adjustments is recommended.

Because Parkinson's disease is progressive, periodic clinical evaluations are recommended; adjustment of the dosage regimen of carbidopa and levodopa extended-release tablets may be required.

Anticholinergic agents, dopamine agonists, and amantadine can be given with carbidopa and levodopa extended-release tablets. Dosage adjustment of carbidopa and levodopa extended-release tablets may be necessary when these agents are added.

A dose of carbidopa and levodopa immediate-release tablets 25 mg/100 mg or 10 mg/100 mg (one half or a whole tablet) can be added to the dosage regimen of carbidopa and levodopa extended-release tablets in selected patients with advanced disease who need additional immediate-release levodopa for a brief time during daytime hours.

Sporadic cases of a symptom complex resembling Neuroleptic Malignant Syndrome (NMS) have been associated with dose reductions and withdrawal of carbidopa and levodopa immediate-release tablets or carbidopa and levodopa extended-release tablets.

Patients should be observed carefully if abrupt reduction or discontinuation of carbidopa and levodopa extended-release tablets is required, especially if the patient is receiving neuroleptics (see WARNINGS).

If general anesthesia is required, carbidopa and levodopa extended-release tablets may be continued as long as the patient is permitted to take oral medication. If therapy is interrupted temporarily, the patient should be observed for symptoms resembling NMS, and the usual dosage should be administered as soon as the patient is able to take oral medication.

DOSAGE AND ADMINISTRATION: Carbidopa and levodopa extended-release tablets contain carbidopa and levodopa in a 1:4 ratio as either the 50 mg/200 mg tablet or the 25 mg/100 mg tablet. The daily dosage of carbidopa and levodopa extended-release tablets must be determined by careful titration. Patients should be monitored closely during the dose adjustment period, particularly with regard to appearance or worsening of involuntary movements, dyskinesias or nausea. Carbidopa and levodopa extended-release tablets should not be chewed or crushed.

    Standard drugs for Parkinson’s disease, other than levodopa without a decarboxylase inhibitor, may be used concomitantly while carbidopa and levodopa extended-release tablets are being administered, although their dosage may have to be adjusted.

    Since carbidopa prevents the reversal of levodopa effects caused by pyridoxine, carbidopa and levodopa extended-release tablets can be given to patients receiving supplemental pyridoxine (vitamin B6).

Initial Dosage: Patients Currently Treated with Conventional Carbidopa-Levodopa Preparations: Studies show that peripheral dopa-decarboxylase is saturated by the bioavailable carbidopa at doses of 70 mg a day and greater. Because the bioavailabilities of carbidopa and levodopa in carbidopa and levodopa immediate-release tablets and carbidopa and levodopa extended-release tablets are different, appropriate adjustments should be made, as shown in Table 2.

**The extent of availability of levodopa from carbidopa and levodopa extended-release tablets was about 70% to 75% relative to intravenous levodopa or standard carbidopa and levodopa immediate-release tablets in the elderly.

***The extent of availability of levodopa from carbidopa and levodopa immediate-release tablets was 99% relative to intravenous levodopa in the healthy elderly.

    Dosage with carbidopa and levodopa extended-release tablets should be substituted at an amount that provides approximately 10% more levodopa per day, although this may need to be increased to a dosage that provides up to 30% more levodopa per day depending on clinical response (see DOSAGE AND ADMINISTRATION: Titration with Carbidopa and Levodopa Extended-release Tablets). The interval between doses of carbidopa and levodopa extended-release tablets should be 4 to 8 hours during the waking day (see CLINICAL PHARMACOLOGY: Pharmacodynamics).

    A guideline for initiation of carbidopa and levodopa extended-release tablets is shown in Table 3.

Carbidopa and Levodopa

Immediate-release Tablets

Carbidopa and Levodopa

Extended-release Tablets

Total Daily Dose*

Levodopa (mg)

Suggested

Dosage Regimen

Patients Currently Treated with Levodopa Without a Decarboxylase Inhibitor: Levodopa must be discontinued at least 12 hours before therapy with carbidopa and levodopa extended-release tablets is started. Carbidopa and levodopa extended-release tablets should be substituted at a dosage that will provide approximately 25% of the previous levodopa dosage. In patients with mild to moderate disease, the initial dose is usually one tablet of 50 mg/200 mg carbidopa and levodopa extended-release tablets b.i.d.

Patients Not Receiving Levodopa: In patients with mild to moderate disease, the initial recommended dose is one tablet of 50 mg/200 mg carbidopa and levodopa extended-release tablets b.i.d. Initial dosage should not be given at intervals of less than 6 hours.

Titration with Carbidopa and Levodopa Extended-release Tablets: Following initiation of therapy, doses and dosing intervals may be increased or decreased depending upon therapeutic response. Most patients have been adequately treated with doses of carbidopa and levodopa extended-release tablets that provide 400 mg to 1600 mg of levodopa per day, administered as divided doses at intervals ranging from 4 to 8 hours during the waking day. Higher doses of carbidopa and levodopa extended-release tablets (2400 mg or more of levodopa per day) and shorter intervals (less than 4 hours) have been used, but are not usually recommended.

    When doses of carbidopa and levodopa extended-release tablets are given at intervals of less than 4 hours, and/or if the divided doses are not equal, it is recommended that the smaller doses be given at the end of the day.

    An interval of at least 3 days between dosage adjustments is recommended.

Maintenance: Because Parkinson's disease is progressive, periodic clinical evaluations are recommended; adjustment of the dosage regimen of carbidopa and levodopa extended-release tablets may be required.

Addition of Other Antiparkinson Medications: Anticholinergic agents, dopamine agonists, and amantadine can be given with carbidopa and levodopa extended-release tablets. Dosage adjustment of carbidopa and levodopa extended-release tablets may be necessary when these agents are added.

    A dose of carbidopa and levodopa immediate-release tablets 25 mg/100 mg or 10 mg/100 mg (one half or a whole tablet) can be added to the dosage regimen of carbidopa and levodopa extended-release tablets in selected patients with advanced disease who need additional immediate-release levodopa for a brief time during daytime hours.

Interruption of Therapy: Sporadic cases of hyperpyrexia and confusion have been associated with dose reductions and withdrawal of carbidopa and levodopa immediate-release tablets or carbidopa and levodopa extended-release tablets.

    Patients should be observed carefully if abrupt reduction or discontinuation of carbidopa and levodopa extended-release tablets is required, especially if the patient is receiving neuroleptics (see WARNINGS).

    If general anesthesia is required, carbidopa and levodopa extended-release tablets may be continued as long as the patient is permitted to take oral medication. If therapy is interrupted temporarily, the patient should be observed for symptoms resembling NMS, and the usual dosage should be administered as soon as the patient is able to take oral medication.

The optimum daily dosage of carbidopa and levodopa must be determined by careful titration in each patient. Carbidopa and levodopa tablets are available in a 1:4 ratio of carbidopa to levodopa (carbidopa and levodopa tablets 25 mg/100 mg) as well as 1:10 ratio (carbidopa and levodopa tablets 25 mg/250 mg and carbidopa and levodopa tablets 10 mg/100 mg). Tablets of the two ratios may be given separately or combined as needed to provide the optimum dosage.

Studies show that peripheral dopa decarboxylase is saturated by carbidopa at approximately 70 to 100 mg a day. Patients receiving less than this amount of carbidopa are more likely to experience nausea and vomiting.

Dosage is best initiated with one tablet of carbidopa and levodopa tablets 25 mg/100 mg three times a day. This dosage schedule provides 75 mg of carbidopa per day. Dosage may be increased by one tablet every day or every other day, as necessary, until a dosage of eight tablets of carbidopa and levodopa tablets 25 mg/100 mg a day is reached. Usual Initial Dosage

If carbidopa and levodopa tablets 10 mg/100 mg are used, dosage may be initiated with one tablet three or four times a day. However, this will not provide an adequate amount of carbidopa for many patients. Dosage may be increased by one tablet every day or every other day until a total of eight tablets (2 tablets q.i.d.) is reached.

A daily dosage of carbidopa and levodopa should be chosen that will provide approximately 25% of the previous levodopa dosage. Patients who are taking less than 1500 mg of levodopa a day should be started on one tablet of carbidopa and levodopa 25 mg/100 mg three or four times a day. The suggested starting dosage for most patients taking more than 1500 mg of levodopa is one tablet of carbidopa and levodopa 25 mg/250 mg three or four times a day. How to Transfer Patients from Levodopa
Levodopa must be discontinued at least twelve hours before starting carbidopa and levodopa tablets.

Therapy should be individualized and adjusted according to the desired therapeutic response. At least 70 to 100 mg of carbidopa per day should be provided. When a greater proportion of carbidopa is required, one tablet of carbidopa and levodopa 25 mg/100 mg may be substituted for each tablet of carbidopa and levodopa 10 mg/100 mg. When more levodopa is required, carbidopa and levodopa tablets 25 mg/250 mg should be substituted for carbidopa and levodopa tablets 25 mg/100 mg or carbidopa and levodopa tablets 10 mg/100 mg. If necessary, the dosage of carbidopa and levodopa tablets 25 mg/250 mg may be increased by one-half or one tablet every day or every other day to a maximum of eight tablets a day. Experience with total daily dosages of carbidopa greater than 200 mg is limited. Maintenance

Because both therapeutic and adverse responses occur more rapidly with carbidopa and levodopa than with levodopa alone, patients should be monitored closely during the dose adjustment period. Specifically, involuntary movements will occur more rapidly with carbidopa and levodopa than with levodopa. The occurrence of involuntary movements may require dosage reduction. Blepharospasm may be a useful early sign of excess dosage in some patients.

Standard drugs for Parkinson's disease, other than levodopa without a decarboxylase inhibitor, may be used concomitantly while carbidopa and levodopa tablets are being administered, although dosage adjustments may be required. Addition of Other Antiparkinsonian Medications

Sporadic cases of a symptom complex resembling Neuroleptic Malignant Syndrome (NMS) have been associated with dose reductions and withdrawal of carbidopa and levodopa tablets. Patients should be observed carefully if abrupt reduction or discontinuation of carbidopa and levodopa tablets is required, especially if the patient is receiving neuroleptics (See ). Interruption of Therapy
WARNINGS

If general anesthesia is required, carbidopa and levodopa may be continued as long as the patient is permitted to take fluids and medication by mouth. If therapy is interrupted temporarily, the patient should be observed for symptoms resembling NMS, and the usual daily dosage may be administered as soon as the patient is able to take oral medication.

The optimum daily dosage of carbidopa and levodopa tablets USP must be determined by careful titration in each patient. Carbidopa and levodopa tablets USP are available in a 1:4 ratio of carbidopa to levodopa (25 mg/100 mg) as well as a 1:10 ratio (25 mg/250 mg and 10 mg/100 mg). Tablets of the two ratios may be given separately or combined as needed to provide the optimum dosage.

Studies show that peripheral dopa decarboxylase is saturated by carbidopa at approximately 70 to 100 mg a day. Patients receiving less than this amount of carbidopa are more likely to experience nausea and vomiting.

Dosage is best initiated with one carbidopa and levodopa tablet USP, 25 mg/100 mg three times a day. This dosage schedule provides 75 mg of carbidopa per day. Dosage may be increased by one tablet every day or every other day, as necessary, until a dosage of eight carbidopa and levodopa tablets USP, 25 mg/100 mg a day is reached.

If carbidopa and levodopa tablets USP, 10 mg/100 mg are used, dosage may be initiated with one tablet three or four times a day. However, this will not provide an adequate amount of carbidopa for many patients. Dosage may be increased by one tablet every day or every other day until a total of eight tablets (2 tablets q.i.d.) is reached.

Levodopa must be discontinued at least twelve hours before starting this combination product. A daily dosage of carbidopa and levodopa tablets USP should be chosen that will provide approximately 25% of the previous levodopa dosage. Patients who are taking less than 1500 mg of levodopa a day should be started on one carbidopa and levodopa tablet USP, 25 mg/100 mg three or four times a day. The suggested starting dosage for most patients taking more than 1500 mg of levodopa is one carbidopa and levodopa tablet USP, 25 mg/250 mg three or four times a day.

Therapy should be individualized and adjusted according to the desired therapeutic response. At least 70 to 100 mg of carbidopa per day should be provided. When a greater proportion of carbidopa is required, one carbidopa and levodopa tablet USP, 25 mg/100 mg may be substituted for each carbidopa and levodopa tablet USP, 10 mg/100 mg. When more levodopa is required, each carbidopa and levodopa tablet USP, 25 mg/250 mg should be substituted for a carbidopa and levodopa tablet USP, 25 mg/100 mg or a carbidopa and levodopa tablet USP, 10 mg/100 mg. If necessary, the dosage of carbidopa and levodopa tablets USP, 25 mg/250 mg may be increased by one-half or one tablet every day or every other day to a maximum of eight tablets a day. Experience with total daily dosages of carbidopa greater than 200 mg is limited.

Because both therapeutic and adverse responses occur more rapidly with this combination product than with levodopa alone, patients should be monitored closely during the dose adjustment period. Specifically, involuntary movements will occur more rapidly with carbidopa and levodopa than with levodopa. The occurrence of involuntary movements may require dosage reduction. Blepharospasm may be a useful early sign of excess dosage in some patients.

Standard drugs for Parkinson’s disease, other than levodopa without a decarboxylase inhibitor, may be used concomitantly while carbidopa and levodopa therapy is being administered, although dosage adjustments may be required.

Sporadic cases of a symptom complex resembling Neuroleptic Malignant Syndrome (NMS) have been associated with dose reductions and withdrawal of carbidopa and levodopa tablets USP. Patients should be observed carefully if abrupt reduction or discontinuation of carbidopa and levodopa tablets USP is required, especially if the patient is receiving neuroleptics (see WARNINGS).

If general anesthesia is required, carbidopa and levodopa therapy may be continued as long as the patient is permitted to take fluids and medication by mouth. If therapy is interrupted temporarily, the patient should be observed for symptoms resembling NMS, and the usual daily dosage may be administered as soon as the patient is able to take oral medication.

The optimum daily dosage of carbidopa and levodopa must be determined by careful titration in each patient. Carbidopa and levodopa tablets are available in a 1:4 ratio of carbidopa to levodopa (25 mg/100 mg) as well as 1:10 ratio (25 mg/250 mg and 10 mg/100 mg). Tablets of the two ratios may be given separately or combined as needed to provide the optimum dosage.

Studies show that peripheral dopa decarboxylase is saturated by carbidopa at approximately 70 to 100 mg a day. Patients receiving less than this amount of carbidopa are more likely to experience nausea and vomiting.

Usual Initial Dosage: Dosage is best initiated with one tablet of carbidopa and levodopa 25 mg/100 mg three times a day. This dosage schedule provides 75 mg of carbidopa per day. Dosage may be increased by one tablet every day or every other day, as necessary, until a dosage of eight tablets of carbidopa and levodopa 25 mg/100 mg a day is reached.

If carbidopa and levodopa 10 mg/100 mg is used, dosage may be initiated with one tablet three or four times a day. However, this will not provide an adequate amount of carbidopa for many patients. Dosage may be increased by one tablet every day or every other day until a total of eight tablets (2 tablets q.i.d.) is reached.

How To Transfer Patients From Levodopa: Levodopa must be discontinued at least twelve hours before starting this combination product. A daily dosage of carbidopa and levodopa should be chosen that will provide approximately 25% of the previous levodopa dosage. Patients who are taking less than 1500 mg of levodopa a day should be started on one tablet of carbidopa and levodopa 25 mg/100 mg three or four times a day. The suggested starting dosage for most patients taking more than 1500 mg of levodopa is one tablet of carbidopa and levodopa 25 mg/250 mg three or four times a day.

Maintenance: Therapy should be individualized and adjusted according to the desired therapeutic response. At least 70 to 100 mg of carbidopa per day should be provided. When a greater proportion of carbidopa is required, one 25 mg/100 mg tablet may be substituted for each 10 mg/100 mg tablet. When more levodopa is required, each 25 mg/250 mg tablet should be substituted for a 25 mg/100 mg tablet or a 10 mg/100 mg tablet. If necessary, the dosage of carbidopa and levodopa 25 mg/250 mg may be increased by one-half or one tablet every day or every other day to a maximum of eight tablets a day. Experience with total daily dosages of carbidopa greater than 200 mg is limited.

Because both therapeutic and adverse responses occur more rapidly with this combination product than with levodopa alone, patients should be monitored closely during the dose adjustment period. Specifically, involuntary movements will occur more rapidly with carbidopa and levodopa than with levodopa. The occurrence of involuntary movements may require dosage reduction. Blepharospasm may be a useful early sign of excess dosage in some patients.

Addition Of Other Antiparkinsonian Medications: Standard drugs for Parkinson's disease, other than levodopa without a decarboxylase inhibitor, may be used concomitantly while carbidopa and levodopa is being administered, although dosage adjustments may be required.

Interruption Of Therapy: Sporadic cases of a symptom complex resembling Neuroleptic Malignant Syndrome (NMS) have been associated with dose reductions and withdrawal of carbidopa and levodopa. Patients should be observed carefully if abrupt reduction or discontinuation of carbidopa and levodopa is required, especially if the patient is receiving neuroleptics. (See WARNINGS.)

If general anesthesia is required, carbidopa and levodopa may be continued as long as the patient is permitted to take fluids and medication by mouth. If therapy is interrupted temporarily, the patient should be observed for symptoms resembling NMS, and the usual daily dosage may be administered as soon as the patient is able to take oral medication.

The optimum daily dosage of carbidopa and levodopa tablets must be determined by careful titration in each patient.

Carbidopa and levodopa tablets are available in a 1:4 ratio of carbidopa to levodopa (carbidopa and levodopa tablets, USP 25 mg/100 mg) as well as 1:10 ratio (carbidopa and levodopa tablets, USP 25 mg/250 mg and carbidopa and levodopa lablets, USP 10 mg/100 mg). Tablets of the two ratios may be given separately or combined as needed to provide the optimum dosage.

Studies show that peripheral dopa decarboxylase is saturated by carbidopa at approximately 70 to 100 mg a day. Patients receiving less than this amount of carbidopa are more likely to experience nausea and vomiting.

The optimum daily dosage of carbidopa and levodopa tablets USP must be determined by careful titration in each patient. Carbidopa and levodopa tablets USP are available in a 1:4 ratio of carbidopa to levodopa (25 mg/100 mg) as well as a 1:10 ratio (25 mg/250 mg and 10 mg/100 mg). Tablets of the two ratios may be given separately or combined as needed to provide the optimum dosage.

Studies show that peripheral dopa decarboxylase is saturated by carbidopa at approximately 70 to 100 mg a day. Patients receiving less than this amount of carbidopa are more likely to experience nausea and vomiting.

Dosage is best initiated with one carbidopa and levodopa tablet USP, 25 mg/100 mg three times a day. This dosage schedule provides 75 mg of carbidopa per day. Dosage may be increased by one tablet every day or every other day, as necessary, until a dosage of eight carbidopa and levodopa tablets USP, 25 mg/100 mg a day is reached.

If carbidopa and levodopa tablets USP, 10 mg/100 mg are used, dosage may be initiated with one tablet three or four times a day. However, this will not provide an adequate amount of carbidopa for many patients. Dosage may be increased by one tablet every day or every other day until a total of eight tablets (2 tablets q.i.d.) is reached.

Levodopa must be discontinued at least twelve hours before starting this combination product. A daily dosage of carbidopa and levodopa tablets USP should be chosen that will provide approximately 25% of the previous levodopa dosage. Patients who are taking less than 1500 mg of levodopa a day should be started on one carbidopa and levodopa tablet USP, 25 mg/100 mg three or four times a day. The suggested starting dosage for most patients taking more than 1500 mg of levodopa is one carbidopa and levodopa tablet USP, 25 mg/250 mg three or four times a day.

Therapy should be individualized and adjusted according to the desired therapeutic response. At least 70 to 100 mg of carbidopa per day should be provided. When a greater proportion of carbidopa is required, one carbidopa and levodopa tablet USP, 25 mg/100 mg may be substituted for each carbidopa and levodopa tablet USP, 10 mg/100 mg. When more levodopa is required, each carbidopa and levodopa tablet USP, 25 mg/250 mg should be substituted for a carbidopa and levodopa tablet USP, 25 mg/100 mg or a carbidopa and levodopa tablet USP, 10 mg/100 mg. If necessary, the dosage of carbidopa and levodopa tablets USP, 25 mg/250 mg may be increased by one-half or one tablet every day or every other day to a maximum of eight tablets a day. Experience with total daily dosages of carbidopa greater than 200 mg is limited.

Because both therapeutic and adverse responses occur more rapidly with this combination product than with levodopa alone, patients should be monitored closely during the dose adjustment period. Specifically, involuntary movements will occur more rapidly with carbidopa and levodopa than with levodopa. The occurrence of involuntary movements may require dosage reduction. Blepharospasm may be a useful early sign of excess dosage in some patients.

Standard drugs for Parkinson’s disease, other than levodopa without a decarboxylase inhibitor, may be used concomitantly while carbidopa and levodopa therapy is being administered, although dosage adjustments may be required.

Sporadic cases of a symptom complex resembling Neuroleptic Malignant Syndrome (NMS) have been associated with dose reductions and withdrawal of carbidopa and levodopa tablets USP. Patients should be observed carefully if abrupt reduction or discontinuation of carbidopa and levodopa tablets USP is required, especially if the patient is receiving neuroleptics (see WARNINGS).

If general anesthesia is required, carbidopa and levodopa therapy may be continued as long as the patient is permitted to take fluids and medication by mouth. If therapy is interrupted temporarily, the patient should be observed for symptoms resembling NMS, and the usual daily dosage may be administered as soon as the patient is able to take oral medication.

The optimum daily dosage of carbidopa and levodopa tablets USP must be determined by careful titration in each patient. Carbidopa and levodopa tablets USP are available in a 1:4 ratio of carbidopa to levodopa (25 mg/100 mg) as well as a 1:10 ratio (25 mg/250 mg and 10 mg/100 mg). Tablets of the two ratios may be given separately or combined as needed to provide the optimum dosage.

Studies show that peripheral dopa decarboxylase is saturated by carbidopa at approximately 70 to 100 mg a day. Patients receiving less than this amount of carbidopa are more likely to experience nausea and vomiting.

Dosage is best initiated with one carbidopa and levodopa tablet USP, 25 mg/100 mg three times a day. This dosage schedule provides 75 mg of carbidopa per day. Dosage may be increased by one tablet every day or every other day, as necessary, until a dosage of eight carbidopa and levodopa tablets USP, 25 mg/100 mg a day is reached.

If carbidopa and levodopa tablets USP, 10 mg/100 mg are used, dosage may be initiated with one tablet three or four times a day. However, this will not provide an adequate amount of carbidopa for many patients. Dosage may be increased by one tablet every day or every other day until a total of eight tablets (2 tablets q.i.d.) is reached.

Levodopa must be discontinued at least twelve hours before starting this combination product. A daily dosage of carbidopa and levodopa tablets USP should be chosen that will provide approximately 25% of the previous levodopa dosage. Patients who are taking less than 1500 mg of levodopa a day should be started on one carbidopa and levodopa tablet USP, 25 mg/100 mg three or four times a day. The suggested starting dosage for most patients taking more than 1500 mg of levodopa is one carbidopa and levodopa tablet USP, 25 mg/250 mg three or four times a day.

Therapy should be individualized and adjusted according to the desired therapeutic response. At least 70 to 100 mg of carbidopa per day should be provided. When a greater proportion of carbidopa is required, one carbidopa and levodopa tablet USP, 25 mg/100 mg may be substituted for each carbidopa and levodopa tablet USP, 10 mg/100 mg. When more levodopa is required, each carbidopa and levodopa tablet USP, 25 mg/250 mg should be substituted for a carbidopa and levodopa tablet USP, 25 mg/100 mg or a carbidopa and levodopa tablet USP, 10 mg/100 mg. If necessary, the dosage of carbidopa and levodopa tablets USP, 25 mg/250 mg may be increased by one-half or one tablet every day or every other day to a maximum of eight tablets a day. Experience with total daily dosages of carbidopa greater than 200 mg is limited.

Because both therapeutic and adverse responses occur more rapidly with this combination product than with levodopa alone, patients should be monitored closely during the dose adjustment period. Specifically, involuntary movements will occur more rapidly with carbidopa and levodopa than with levodopa. The occurrence of involuntary movements may require dosage reduction. Blepharospasm may be a useful early sign of excess dosage in some patients.

Standard drugs for Parkinson’s disease, other than levodopa without a decarboxylase inhibitor, may be used concomitantly while carbidopa and levodopa therapy is being administered, although dosage adjustments may be required.

Sporadic cases of a symptom complex resembling Neuroleptic Malignant Syndrome (NMS) have been associated with dose reductions and withdrawal of carbidopa and levodopa tablets USP. Patients should be observed carefully if abrupt reduction or discontinuation of carbidopa and levodopa tablets USP is required, especially if the patient is receiving neuroleptics (see WARNINGS).

If general anesthesia is required, carbidopa and levodopa therapy may be continued as long as the patient is permitted to take fluids and medication by mouth. If therapy is interrupted temporarily, the patient should be observed for symptoms resembling NMS, and the usual daily dosage may be administered as soon as the patient is able to take oral medication.

The optimum daily dosage of carbidopa and levodopa tablets USP must be determined by careful titration in each patient. Carbidopa and levodopa tablets USP are available in a 1:4 ratio of carbidopa to levodopa (25 mg/100 mg) as well as a 1:10 ratio (25 mg/250 mg and 10 mg/100 mg). Tablets of the two ratios may be given separately or combined as needed to provide the optimum dosage.

Studies show that peripheral dopa decarboxylase is saturated by carbidopa at approximately 70 to 100 mg a day. Patients receiving less than this amount of carbidopa are more likely to experience nausea and vomiting.

Dosage is best initiated with one carbidopa and levodopa tablet USP, 25 mg/100 mg three times a day. This dosage schedule provides 75 mg of carbidopa per day. Dosage may be increased by one tablet every day or every other day, as necessary, until a dosage of eight carbidopa and levodopa tablets USP, 25 mg/100 mg a day is reached.

If carbidopa and levodopa tablets USP, 10 mg/100 mg are used, dosage may be initiated with one tablet three or four times a day. However, this will not provide an adequate amount of carbidopa for many patients. Dosage may be increased by one tablet every day or every other day until a total of eight tablets (2 tablets q.i.d.) is reached.

Levodopa must be discontinued at least twelve hours before starting this combination product. A daily dosage of carbidopa and levodopa tablets USP should be chosen that will provide approximately 25% of the previous levodopa dosage. Patients who are taking less than 1500 mg of levodopa a day should be started on one carbidopa and levodopa tablet USP, 25 mg/100 mg three or four times a day. The suggested starting dosage for most patients taking more than 1500 mg of levodopa is one carbidopa and levodopa tablet USP, 25 mg/250 mg three or four times a day.

Therapy should be individualized and adjusted according to the desired therapeutic response. At least 70 to 100 mg of carbidopa per day should be provided. When a greater proportion of carbidopa is required, one carbidopa and levodopa tablet USP, 25 mg/100 mg may be substituted for each carbidopa and levodopa tablet USP, 10 mg/100 mg. When more levodopa is required, each carbidopa and levodopa tablet USP, 25 mg/250 mg should be substituted for a carbidopa and levodopa tablet USP, 25 mg/100 mg or a carbidopa and levodopa tablet USP, 10 mg/100 mg. If necessary, the dosage of carbidopa and levodopa tablets USP, 25 mg/250 mg may be increased by one-half or one tablet every day or every other day to a maximum of eight tablets a day. Experience with total daily dosages of carbidopa greater than 200 mg is limited.

Because both therapeutic and adverse responses occur more rapidly with this combination product than with levodopa alone, patients should be monitored closely during the dose adjustment period. Specifically, involuntary movements will occur more rapidly with carbidopa and levodopa than with levodopa. The occurrence of involuntary movements may require dosage reduction. Blepharospasm may be a useful early sign of excess dosage in some patients.

Standard drugs for Parkinson’s disease, other than levodopa without a decarboxylase inhibitor, may be used concomitantly while carbidopa and levodopa therapy is being administered, although dosage adjustments may be required.

Sporadic cases of a symptom complex resembling Neuroleptic Malignant Syndrome (NMS) have been associated with dose reductions and withdrawal of carbidopa and levodopa tablets USP. Patients should be observed carefully if abrupt reduction or discontinuation of carbidopa and levodopa tablets USP is required, especially if the patient is receiving neuroleptics (see WARNINGS).

If general anesthesia is required, carbidopa and levodopa therapy may be continued as long as the patient is permitted to take fluids and medication by mouth. If therapy is interrupted temporarily, the patient should be observed for symptoms resembling NMS, and the usual daily dosage may be administered as soon as the patient is able to take oral medication.

The optimum daily dosage of carbidopa and levodopa must be determined by careful titration in each patient. Carbidopa and levodopa tablets are available in a 1:4 ratio of carbidopa to levodopa (25 mg/100 mg) as well as 1:10 ratio (25 mg/250 mg and 10 mg/100 mg). Tablets of the two ratios may be given separately or combined as needed to provide the optimum dosage.

Studies show that peripheral dopa decarboxylase is saturated by carbidopa at approximately 70 to 100 mg a day. Patients receiving less than this amount of carbidopa are more likely to experience nausea and vomiting.

Usual Initial Dosage: Dosage is best initiated with one tablet of carbidopa and levodopa 25 mg/100 mg three times a day. This dosage schedule provides 75 mg of carbidopa per day. Dosage may be increased by one tablet every day or every other day, as necessary, until a dosage of eight tablets of carbidopa and levodopa 25 mg/100 mg a day is reached.

If carbidopa and levodopa 10 mg/100 mg is used, dosage may be initiated with one tablet three or four times a day. However, this will not provide an adequate amount of carbidopa for many patients. Dosage may be increased by one tablet every day or every other day until a total of eight tablets (2 tablets q.i.d.) is reached.

How To Transfer Patients From Levodopa: Levodopa must be discontinued at least twelve hours before starting this combination product. A daily dosage of carbidopa and levodopa should be chosen that will provide approximately 25% of the previous levodopa dosage. Patients who are taking less than 1500 mg of levodopa a day should be started on one tablet of carbidopa and levodopa 25 mg/100 mg three or four times a day. The suggested starting dosage for most patients taking more than 1500 mg of levodopa is one tablet of carbidopa and levodopa 25 mg/250 mg three or four times a day.

Maintenance: Therapy should be individualized and adjusted according to the desired therapeutic response. At least 70 to 100 mg of carbidopa per day should be provided. When a greater proportion of carbidopa is required, one 25 mg/100 mg tablet may be substituted for each 10 mg/100 mg tablet. When more levodopa is required, each 25 mg/250 mg tablet should be substituted for a 25 mg/100 mg tablet or a 10 mg/100 mg tablet. If necessary, the dosage of carbidopa and levodopa 25 mg/250 mg may be increased by one-half or one tablet every day or every other day to a maximum of eight tablets a day. Experience with total daily dosages of carbidopa greater than 200 mg is limited.

Because both therapeutic and adverse responses occur more rapidly with this combination product than with levodopa alone, patients should be monitored closely during the dose adjustment period. Specifically, involuntary movements will occur more rapidly with carbidopa and levodopa than with levodopa. The occurrence of involuntary movements may require dosage reduction. Blepharospasm may be a useful early sign of excess dosage in some patients.

Addition Of Other Antiparkinsonian Medications: Standard drugs for Parkinson's disease, other than levodopa without a decarboxylase inhibitor, may be used concomitantly while carbidopa and levodopa is being administered, although dosage adjustments may be required.

Interruption Of Therapy: Sporadic cases of a symptom complex resembling Neuroleptic Malignant Syndrome (NMS) have been associated with dose reductions and withdrawal of carbidopa and levodopa. Patients should be observed carefully if abrupt reduction or discontinuation of carbidopa and levodopa is required, especially if the patient is receiving neuroleptics. (See WARNINGS.)

If general anesthesia is required, carbidopa and levodopa may be continued as long as the patient is permitted to take fluids and medication by mouth. If therapy is interrupted temporarily, the patient should be observed for symptoms resembling NMS, and the usual daily dosage may be administered as soon as the patient is able to take oral medication.

Carbidopa and levodopa extended release tablets contain carbidopa and levodopa in a 1:4 ratio as either the 50 mg/200 mg tablet or the 25 mg/100 mg tablet. The daily dosage of carbidopa and levodopa extended release tablets must be determined by careful titration. Patients should be monitored closely during the dose adjustment period, particularly with regard to appearance or worsening of involuntary movements, dyskinesias or nausea. Carbidopa and levodopa extended release tablets 50 mg/200 mg may be administered as whole or as half-tablets which should not be chewed or crushed. Carbidopa and levodopa extended release tablets 25 mg/100 mg may be used in combination with carbidopa and levodopa extended release tablets 50 mg/200 mg to titrate to the optimum dosage, or as an alternative to the 50 mg/200 mg half-tablet.

Standard drugs for Parkinson’s disease, other than levodopa without a decarboxylase inhibitor, may be used concomitantly while carbidopa and levodopa extended release tablet is being administered, although their dosage may have to be adjusted.

Since carbidopa prevents the reversal of levodopa effects caused by pyridoxine, carbidopa and levodopa extended release tablets can be given to patients receiving supplemental pyridoxine (vitamin B6).

Patients currently treated with conventional carbidopa and levodopa preparations: Studies show that peripheral dopa-decarboxylase is saturated by the bioavailable carbidopa at doses of 70 mg a day and greater. Because the bioavailabilities of carbidopa and levodopa in carbidopa and levodopa tablets and carbidopa and levodopa extended release tablets are different, appropriate adjustments should be made, as shown in Table II.

Dosage with carbidopa and levodopa extended release tablets should be substituted at an amount that provides approximately 10% more levodopa per day, although this may need to be increased to a dosage that provides up to 30% more levodopa per day depending on clinical response (see DOSAGE AND ADMINISTRATION, Titration). The interval between doses of carbidopa and levodopa extended release tablets should be 4-8 hours during the waking day (See CLINICAL PHARMACOLOGY, Pharmacodynamics).

A guideline for initiation of carbidopa and levodopa extended release tablets is shown in Table III.

Levodopa must be discontinued at least twelve hours before therapy with carbidopa and levodopa extended release tablets is started. Carbidopa and levodopa extended release tablets should be substituted at a dosage that will provide approximately 25% of the previous levodopa dosage. In patients with mild to moderate disease, the initial dose is usually 1 tablet of carbidopa and levodopa extended release tablets 50 mg/200 mg b.i.d.

In patients with mild to moderate disease, the initial recommended dose is 1 tablet of carbidopa and levodopa extended release tablets 50 mg/200 mg b.i.d. Initial dosage should not be given at intervals of less than 6 hours.

Following initiation of therapy, doses and dosing intervals may be increased or decreased depending upon therapeutic response. Most patients have been adequately treated with doses of carbidopa and levodopa extended release tablets that provide 400 to 1600 mg of levodopa per day, administered as divided doses at intervals ranging from 4 to 8 hours during the waking day. Higher doses of carbidopa and levodopa extended release tablets (2400 mg or more of levodopa per day) and shorter intervals (less than 4 hours) have been used, but are not usually recommended.

When doses of carbidopa and levodopa extended release tablets are given at intervals of less than 4 hours, and/or if the divided doses are not equal, it is recommended that the smaller doses be given at the end of the day.

An interval of at least 3 days between dosage adjustments is recommended.

Because Parkinson’s disease is progressive, periodic clinical evaluations are recommended; adjustment of the dosage regimen of carbidopa and levodopa extended release tablets may be required.

Anticholinergic agents, dopamine agonists, and amantadine can be given with carbidopa and levodopa extended release tablets. Dosage adjustment of carbidopa and levodopa extended release tablets may be necessary when these agents are added.

A dose of carbidopa and levodopa tablets 25 mg/100 mg or 10 mg/100 mg (one half or a whole tablet) can be added to the dosage regimen of carbidopa and levodopa extended release tablets in selected patients with advanced disease who need additional immediate-release levodopa for a brief time during daytime hours.

Sporadic cases of a symptom complex resembling Neuroleptic Malignant Syndrome (NMS) have been associated with dose reductions and withdrawal of carbidopa and levodopa tablets or carbidopa and levodopa extended release tablets.

Patients should be observed carefully if abrupt reduction or discontinuation of carbidopa and levodopa extended release tablets is required, especially if the patient is receiving neuroleptics (See WARNINGS).

If general anesthesia is required, carbidopa and levodopa extended release tablets may be continued as long as the patient is permitted to take oral medication. If therapy is interrupted temporarily, the patient should be observed for symptoms resembling NMS, and the usual dosage should be administered as soon as the patient is able to take oral medication.

The optimum daily dosage of carbidopa and levodopa must be determined by careful titration in each patient. Carbidopa and levodopa tablets are available in a 1:4 ratio of carbidopa to levodopa (carbidopa and levodopa tablets 25 mg/100 mg) as well as 1:10 ratio (carbidopa and levodopa tablets 25 mg/250 mg and carbidopa and levodopa tablets 10 mg/100 mg). Tablets of the two ratios may be given separately or combined as needed to provide the optimum dosage.

Studies show that peripheral dopa decarboxylase is saturated by carbidopa at approximately 70 to 100 mg a day. Patients receiving less than this amount of carbidopa are more likely to experience nausea and vomiting.

Usual Initial Dosage
Dosage is best initiated with one tablet of carbidopa and levodopa tablets 25 mg/100 mg three times a day. This dosage schedule provides 75 mg of carbidopa per day. Dosage may be increased by one tablet every day or every other day, as necessary, until a dosage of eight tablets of carbidopa and levodopa tablets 25 mg/100 mg a day is reached.

If carbidopa and levodopa tablets 10 mg/100 mg are used, dosage may be initiated with one tablet three or four times a day. However, this will not provide an adequate amount of carbidopa for many patients. Dosage may be increased by one tablet every day or every other day until a total of eight tablets (2 tablets q.i.d.) is reached.

How to Transfer Patients from Levodopa
Levodopa must be discontinued at least twelve hours before starting carbidopa and levodopa tablets. A daily dosage of carbidopa and levodopa should be chosen that will provide approximately 25% of the previous levodopa dosage. Patients who are taking less than 1500 mg of levodopa a day should be started on one tablet of carbidopa and levodopa 25 mg/100 mg three or four times a day. The suggested starting dosage for most patients taking more than 1500 mg of levodopa is one tablet of carbidopa and levodopa 25 mg/250 mg three or four times a day.

Maintenance
Therapy should be individualized and adjusted according to the desired therapeutic response. At least 70 to 100 mg of carbidopa per day should be provided. When a greater proportion of carbidopa is required, one tablet of carbidopa and levodopa 25 mg/100 mg may be substituted for each tablet of carbidopa and levodopa 10 mg/100 mg. When more levodopa is required, carbidopa and levodopa tablets 25 mg/250 mg should be substituted for carbidopa and levodopa tablets 25 mg/100 mg or carbidopa and levodopa tablets 10 mg/100 mg. If necessary, the dosage of carbidopa and levodopa tablets 25 mg/250 mg may be increased by one-half or one tablet every day or every other day to a maximum of eight tablets a day. Experience with total daily dosages of carbidopa greater than 200 mg is limited.

Because both therapeutic and adverse responses occur more rapidly with carbidopa and levodopa than with levodopa alone, patients should be monitored closely during the dose adjustment period. Specifically, involuntary movements will occur more rapidly with carbidopa and levodopa than with levodopa. The occurrence of involuntary movements may require dosage reduction. Blepharospasm may be a useful early sign of excess dosage in some patients.

Addition of Other Antiparkinsonian Medications
Standard drugs for Parkinson's disease, other than levodopa without a decarboxylase inhibitor, may be used concomitantly while carbidopa and levodopa tablets are being administered, although dosage adjustments may be required.

Interruption of Therapy
Sporadic cases of a symptom complex resembling Neuroleptic Malignant Syndrome (NMS) have been associated with dose reductions and withdrawal of carbidopa and levodopa tablets. Patients should be observed carefully if abrupt reduction or discontinuation of carbidopa and levodopa tablets is required, especially if the patient is receiving neuroleptics (See WARNINGS).

If general anesthesia is required, carbidopa and levodopa may be continued as long as the patient is permitted to take fluids and medication by mouth. If therapy is interrupted temporarily, the patient should be observed for symptoms resembling NMS, and the usual daily dosage may be administered as soon as the patient is able to take oral medication.

The optimum daily dosage of carbidopa and levodopa must be determined by careful titration in each patient. Carbidopa and levodopa tablets are available in a 1:4 ratio of carbidopa to levodopa (carbidopa and levodopa tablets 25 mg/100 mg) as well as 1:10 ratio (carbidopa and levodopa tablets 25 mg/250 mg and carbidopa and levodopa tablets 10 mg/100 mg). Tablets of the two ratios may be given separately or combined as needed to provide the optimum dosage.

Studies show that peripheral dopa decarboxylase is saturated by carbidopa at approximately 70 to 100 mg a day. Patients receiving less than this amount of carbidopa are more likely to experience nausea and vomiting.

Usual Initial Dosage
Dosage is best initiated with one tablet of carbidopa and levodopa tablets 25 mg/100 mg three times a day. This dosage schedule provides 75 mg of carbidopa per day. Dosage may be increased by one tablet every day or every other day, as necessary, until a dosage of eight tablets of carbidopa and levodopa tablets 25 mg/100 mg a day is reached.

If carbidopa and levodopa tablets 10 mg/100 mg are used, dosage may be initiated with one tablet three or four times a day. However, this will not provide an adequate amount of carbidopa for many patients. Dosage may be increased by one tablet every day or every other day until a total of eight tablets (2 tablets q.i.d.) is reached.

How to Transfer Patients from Levodopa
Levodopa must be discontinued at least twelve hours before starting carbidopa and levodopa tablets. A daily dosage of carbidopa and levodopa should be chosen that will provide approximately 25% of the previous levodopa dosage. Patients who are taking less than 1500 mg of levodopa a day should be started on one tablet of carbidopa and levodopa 25 mg/100 mg three or four times a day. The suggested starting dosage for most patients taking more than 1500 mg of levodopa is one tablet of carbidopa and levodopa 25 mg/250 mg three or four times a day.

Maintenance
Therapy should be individualized and adjusted according to the desired therapeutic response. At least 70 to 100 mg of carbidopa per day should be provided. When a greater proportion of carbidopa is required, one tablet of carbidopa and levodopa 25 mg/100 mg may be substituted for each tablet of carbidopa and levodopa 10 mg/100 mg. When more levodopa is required, carbidopa and levodopa tablets 25 mg/250 mg should be substituted for carbidopa and levodopa tablets 25 mg/100 mg or carbidopa and levodopa tablets 10 mg/100 mg. If necessary, the dosage of carbidopa and levodopa tablets 25 mg/250 mg may be increased by one-half or one tablet every day or every other day to a maximum of eight tablets a day. Experience with total daily dosages of carbidopa greater than 200 mg is limited.

Because both therapeutic and adverse responses occur more rapidly with carbidopa and levodopa than with levodopa alone, patients should be monitored closely during the dose adjustment period. Specifically, involuntary movements will occur more rapidly with carbidopa and levodopa than with levodopa. The occurrence of involuntary movements may require dosage reduction. Blepharospasm may be a useful early sign of excess dosage in some patients.

Addition of Other Antiparkinsonian Medications
Standard drugs for Parkinson's disease, other than levodopa without a decarboxylase inhibitor, may be used concomitantly while carbidopa and levodopa tablets are being administered, although dosage adjustments may be required.

Interruption of Therapy
Sporadic cases of a symptom complex resembling Neuroleptic Malignant Syndrome (NMS) have been associated with dose reductions and withdrawal of carbidopa and levodopa tablets. Patients should be observed carefully if abrupt reduction or discontinuation of carbidopa and levodopa tablets is required, especially if the patient is receiving neuroleptics (See WARNINGS).

If general anesthesia is required, carbidopa and levodopa may be continued as long as the patient is permitted to take fluids and medication by mouth. If therapy is interrupted temporarily, the patient should be observed for symptoms resembling NMS, and the usual daily dosage may be administered as soon as the patient is able to take oral medication.

The optimum daily dosage of carbidopa and levodopa tablets USP must be determined by careful titration in each patient. Carbidopa and levodopa tablets USP are available in a 1:4 ratio of carbidopa to levodopa (25 mg/100 mg) as well as a 1:10 ratio (25 mg/250 mg and 10 mg/100 mg). Tablets of the two ratios may be given separately or combined as needed to provide the optimum dosage.

Studies show that peripheral dopa decarboxylase is saturated by carbidopa at approximately 70 to 100 mg a day. Patients receiving less than this amount of carbidopa are more likely to experience nausea and vomiting.

Dosage is best initiated with one carbidopa and levodopa tablet USP, 25 mg/100 mg three times a day. This dosage schedule provides 75 mg of carbidopa per day. Dosage may be increased by one tablet every day or every other day, as necessary, until a dosage of eight carbidopa and levodopa tablets USP, 25 mg/100 mg a day is reached.

If carbidopa and levodopa tablets USP, 10 mg/100 mg are used, dosage may be initiated with one tablet three or four times a day. However, this will not provide an adequate amount of carbidopa for many patients. Dosage may be increased by one tablet every day or every other day until a total of eight tablets (2 tablets q.i.d.) is reached.

Levodopa must be discontinued at least twelve hours before starting this combination product. A daily dosage of carbidopa and levodopa tablets USP should be chosen that will provide approximately 25% of the previous levodopa dosage. Patients who are taking less than 1500 mg of levodopa a day should be started on one carbidopa and levodopa tablet USP, 25 mg/100 mg three or four times a day. The suggested starting dosage for most patients taking more than 1500 mg of levodopa is one carbidopa and levodopa tablet USP, 25 mg/250 mg three or four times a day.

Therapy should be individualized and adjusted according to the desired therapeutic response. At least 70 to 100 mg of carbidopa per day should be provided. When a greater proportion of carbidopa is required, one carbidopa and levodopa tablet USP, 25 mg/100 mg may be substituted for each carbidopa and levodopa tablet USP, 10 mg/100 mg. When more levodopa is required, each carbidopa and levodopa tablet USP, 25 mg/250 mg should be substituted for a carbidopa and levodopa tablet USP, 25 mg/100 mg or a carbidopa and levodopa tablet USP, 10 mg/100 mg. If necessary, the dosage of carbidopa and levodopa tablets USP, 25 mg/250 mg may be increased by one-half or one tablet every day or every other day to a maximum of eight tablets a day. Experience with total daily dosages of carbidopa greater than 200 mg is limited.

Because both therapeutic and adverse responses occur more rapidly with this combination product than with levodopa alone, patients should be monitored closely during the dose adjustment period. Specifically, involuntary movements will occur more rapidly with carbidopa and levodopa than with levodopa. The occurrence of involuntary movements may require dosage reduction. Blepharospasm may be a useful early sign of excess dosage in some patients.

Standard drugs for Parkinson’s disease, other than levodopa without a decarboxylase inhibitor, may be used concomitantly while carbidopa and levodopa therapy is being administered, although dosage adjustments may be required.

Sporadic cases of a symptom complex resembling Neuroleptic Malignant Syndrome (NMS) have been associated with dose reductions and withdrawal of carbidopa and levodopa tablets USP. Patients should be observed carefully if abrupt reduction or discontinuation of carbidopa and levodopa tablets USP is required, especially if the patient is receiving neuroleptics (see WARNINGS).

If general anesthesia is required, carbidopa and levodopa therapy may be continued as long as the patient is permitted to take fluids and medication by mouth. If therapy is interrupted temporarily, the patient should be observed for symptoms resembling NMS, and the usual daily dosage may be administered as soon as the patient is able to take oral medication.

The recommended dose for adults and children over 12 years of age is one 800 mg tablet three to four times a day.

The optimum daily dosage of carbidopa and levodopa tablets USP must be determined by careful titration in each patient. Carbidopa and levodopa tablets USP are available in a 1:4 ratio of carbidopa to levodopa (25 mg/100 mg) as well as a 1:10 ratio (25 mg/250 mg and 10 mg/100 mg). Tablets of the two ratios may be given separately or combined as needed to provide the optimum dosage.

Studies show that peripheral dopa decarboxylase is saturated by carbidopa at approximately 70 to 100 mg a day. Patients receiving less than this amount of carbidopa are more likely to experience nausea and vomiting.

Dosage is best initiated with one carbidopa and levodopa tablet USP, 25 mg/100 mg three times a day. This dosage schedule provides 75 mg of carbidopa per day. Dosage may be increased by one tablet every day or every other day, as necessary, until a dosage of eight carbidopa and levodopa tablets USP, 25 mg/100 mg a day is reached.

If carbidopa and levodopa tablets USP, 10 mg/100 mg are used, dosage may be initiated with one tablet three or four times a day. However, this will not provide an adequate amount of carbidopa for many patients. Dosage may be increased by one tablet every day or every other day until a total of eight tablets (2 tablets q.i.d.) is reached.

Levodopa must be discontinued at least twelve hours before starting this combination product. A daily dosage of carbidopa and levodopa tablets USP should be chosen that will provide approximately 25% of the previous levodopa dosage. Patients who are taking less than 1500 mg of levodopa a day should be started on one carbidopa and levodopa tablet USP, 25 mg/100 mg three or four times a day. The suggested starting dosage for most patients taking more than 1500 mg of levodopa is one carbidopa and levodopa tablet USP, 25 mg/250 mg three or four times a day.

Therapy should be individualized and adjusted according to the desired therapeutic response. At least 70 to 100 mg of carbidopa per day should be provided. When a greater proportion of carbidopa is required, one carbidopa and levodopa tablet USP, 25 mg/100 mg may be substituted for each carbidopa and levodopa tablet USP, 10 mg/100 mg. When more levodopa is required, each carbidopa and levodopa tablet USP, 25 mg/250 mg should be substituted for a carbidopa and levodopa tablet USP, 25 mg/100 mg or a carbidopa and levodopa tablet USP, 10 mg/100 mg. If necessary, the dosage of carbidopa and levodopa tablets USP, 25 mg/250 mg may be increased by one-half or one tablet every day or every other day to a maximum of eight tablets a day. Experience with total daily dosages of carbidopa greater than 200 mg is limited.

Because both therapeutic and adverse responses occur more rapidly with this combination product than with levodopa alone, patients should be monitored closely during the dose adjustment period. Specifically, involuntary movements will occur more rapidly with carbidopa and levodopa than with levodopa. The occurrence of involuntary movements may require dosage reduction. Blepharospasm may be a useful early sign of excess dosage in some patients.

Standard drugs for Parkinson’s disease, other than levodopa without a decarboxylase inhibitor, may be used concomitantly while carbidopa and levodopa therapy is being administered, although dosage adjustments may be required.

Sporadic cases of a symptom complex resembling Neuroleptic Malignant Syndrome (NMS) have been associated with dose reductions and withdrawal of carbidopa and levodopa tablets USP. Patients should be observed carefully if abrupt reduction or discontinuation of carbidopa and levodopa tablets USP is required, especially if the patient is receiving neuroleptics (see WARNINGS).

If general anesthesia is required, carbidopa and levodopa therapy may be continued as long as the patient is permitted to take fluids and medication by mouth. If therapy is interrupted temporarily, the patient should be observed for symptoms resembling NMS, and the usual daily dosage may be administered as soon as the patient is able to take oral medication.

The optimum daily dosage of carbidopa and levodopa must be determined by careful titration in each patient. Carbidopa and levodopa tablets are available in a 1:4 ratio of carbidopa to levodopa (25 mg/100 mg) as well as 1:10 ratio (25 mg/250 mg and 10 mg/100 mg). Tablets of the two ratios may be given separately or combined as needed to provide the optimum dosage.

Studies show that peripheral dopa decarboxylase is saturated by carbidopa at approximately 70 to 100 mg a day. Patients receiving less than this amount of carbidopa are more likely to experience nausea and vomiting.

Usual Initial Dosage: Dosage is best initiated with one tablet of carbidopa and levodopa 25 mg/100 mg three times a day. This dosage schedule provides 75 mg of carbidopa per day. Dosage may be increased by one tablet every day or every other day, as necessary, until a dosage of eight tablets of carbidopa and levodopa 25 mg/100 mg a day is reached.

If carbidopa and levodopa 10 mg/100 mg is used, dosage may be initiated with one tablet three or four times a day. However, this will not provide an adequate amount of carbidopa for many patients. Dosage may be increased by one tablet every day or every other day until a total of eight tablets (2 tablets q.i.d.) is reached.

How To Transfer Patients From Levodopa: Levodopa must be discontinued at least twelve hours before starting this combination product. A daily dosage of carbidopa and levodopa should be chosen that will provide approximately 25% of the previous levodopa dosage. Patients who are taking less than 1500 mg of levodopa a day should be started on one tablet of carbidopa and levodopa 25 mg/100 mg three or four times a day. The suggested starting dosage for most patients taking more than 1500 mg of levodopa is one tablet of carbidopa and levodopa 25 mg/250 mg three or four times a day.

Maintenance: Therapy should be individualized and adjusted according to the desired therapeutic response. At least 70 to 100 mg of carbidopa per day should be provided. When a greater proportion of carbidopa is required, one 25 mg/100 mg tablet may be substituted for each 10 mg/100 mg tablet. When more levodopa is required, each 25 mg/250 mg tablet should be substituted for a 25 mg/100 mg tablet or a 10 mg/100 mg tablet. If necessary, the dosage of carbidopa and levodopa 25 mg/250 mg may be increased by one-half or one tablet every day or every other day to a maximum of eight tablets a day. Experience with total daily dosages of carbidopa greater than 200 mg is limited.

Because both therapeutic and adverse responses occur more rapidly with this combination product than with levodopa alone, patients should be monitored closely during the dose adjustment period. Specifically, involuntary movements will occur more rapidly with carbidopa and levodopa than with levodopa. The occurrence of involuntary movements may require dosage reduction. Blepharospasm may be a useful early sign of excess dosage in some patients.

Addition Of Other Antiparkinsonian Medications: Standard drugs for Parkinson's disease, other than levodopa without a decarboxylase inhibitor, may be used concomitantly while carbidopa and levodopa is being administered, although dosage adjustments may be required.

Interruption Of Therapy: Sporadic cases of a symptom complex resembling Neuroleptic Malignant Syndrome (NMS) have been associated with dose reductions and withdrawal of carbidopa and levodopa. Patients should be observed carefully if abrupt reduction or discontinuation of carbidopa and levodopa is required, especially if the patient is receiving neuroleptics. (See WARNINGS.)

If general anesthesia is required, carbidopa and levodopa may be continued as long as the patient is permitted to take fluids and medication by mouth. If therapy is interrupted temporarily, the patient should be observed for symptoms resembling NMS, and the usual daily dosage may be administered as soon as the patient is able to take oral medication.

age

dose

adults and children 12 years and over

10 – 20 mL every 4 hours

children under 12 years

do not use

The optimum daily dosage of carbidopa and levodopa must be determined by careful titration in each patient. Carbidopa and levodopa tablets are available in a 1:4 ratio of carbidopa to levodopa (carbidopa and levodopa tablets 25 mg/100 mg) as well as 1:10 ratio (carbidopa and levodopa tablets 25 mg/250 mg and carbidopa and levodopa tablets 10 mg/100 mg). Tablets of the two ratios may be given separately or combined as needed to provide the optimum dosage.

Studies show that peripheral dopa decarboxylase is saturated by carbidopa at approximately 70 to 100 mg a day. Patients receiving less than this amount of carbidopa are more likely to experience nausea and vomiting.

Usual Initial Dosage
Dosage is best initiated with one tablet of carbidopa and levodopa tablets 25 mg/100 mg three times a day. This dosage schedule provides 75 mg of carbidopa per day. Dosage may be increased by one tablet every day or every other day, as necessary, until a dosage of eight tablets of carbidopa and levodopa tablets 25 mg/100 mg a day is reached.

If carbidopa and levodopa tablets 10 mg/100 mg are used, dosage may be initiated with one tablet three or four times a day. However, this will not provide an adequate amount of carbidopa for many patients. Dosage may be increased by one tablet every day or every other day until a total of eight tablets (2 tablets q.i.d.) is reached.

How to Transfer Patients from Levodopa
Levodopa must be discontinued at least twelve hours before starting carbidopa and levodopa tablets. A daily dosage of carbidopa and levodopa should be chosen that will provide approximately 25% of the previous levodopa dosage. Patients who are taking less than 1500 mg of levodopa a day should be started on one tablet of carbidopa and levodopa 25 mg/100 mg three or four times a day. The suggested starting dosage for most patients taking more than 1500 mg of levodopa is one tablet of carbidopa and levodopa 25 mg/250 mg three or four times a day.

Maintenance
Therapy should be individualized and adjusted according to the desired therapeutic response. At least 70 to 100 mg of carbidopa per day should be provided. When a greater proportion of carbidopa is required, one tablet of carbidopa and levodopa 25 mg/100 mg may be substituted for each tablet of carbidopa and levodopa 10 mg/100 mg. When more levodopa is required, carbidopa and levodopa tablets 25 mg/250 mg should be substituted for carbidopa and levodopa tablets 25 mg/100 mg or carbidopa and levodopa tablets 10 mg/100 mg. If necessary, the dosage of carbidopa and levodopa tablets 25 mg/250 mg may be increased by one-half or one tablet every day or every other day to a maximum of eight tablets a day. Experience with total daily dosages of carbidopa greater than 200 mg is limited.

Because both therapeutic and adverse responses occur more rapidly with carbidopa and levodopa than with levodopa alone, patients should be monitored closely during the dose adjustment period. Specifically, involuntary movements will occur more rapidly with carbidopa and levodopa than with levodopa. The occurrence of involuntary movements may require dosage reduction. Blepharospasm may be a useful early sign of excess dosage in some patients.

Addition of Other Antiparkinsonian Medications
Standard drugs for Parkinson's disease, other than levodopa without a decarboxylase inhibitor, may be used concomitantly while carbidopa and levodopa tablets are being administered, although dosage adjustments may be required.

Interruption of Therapy
Sporadic cases of a symptom complex resembling Neuroleptic Malignant Syndrome (NMS) have been associated with dose reductions and withdrawal of carbidopa and levodopa tablets. Patients should be observed carefully if abrupt reduction or discontinuation of carbidopa and levodopa tablets is required, especially if the patient is receiving neuroleptics (See WARNINGS).

If general anesthesia is required, carbidopa and levodopa may be continued as long as the patient is permitted to take fluids and medication by mouth. If therapy is interrupted temporarily, the patient should be observed for symptoms resembling NMS, and the usual daily dosage may be administered as soon as the patient is able to take oral medication.

Nitrofurantoin capsules (macrocrystals) should be given with food to improve drug absorption and, in some patients, tolerance.

50 mg to 100 mg four times a day -- the lower dosage level is recommended for uncomplicated urinary tract infections.

5 to 7 mg/kg of body weight per 24 hours, given in four divided doses (contraindicated under one month of age).

Therapy should be continued for one week or for at least 3 days after sterility of the urine is obtained. Continued infection indicates the need for reevaluation.

For long-term suppressive therapy in adults, a reduction of dosage to 50-100 mg at bedtime may be adequate. For long-term suppressive therapy in pediatric patients, doses as low as 1 mg/kg per 24 hours, given in a single dose or in two divided doses, may be adequate. SEE WARNINGS SECTION REGARDING RISKS ASSOCIATED WITH LONG-TERM THERAPY.

The optimum daily dosage of carbidopa and levodopa must be determined by careful titration in each patient. Carbidopa and levodopa tablets are available in a 1:4 ratio of carbidopa to levodopa (carbidopa and levodopa tablets 25 mg/100 mg) as well as 1:10 ratio (carbidopa and levodopa tablets 25 mg/250 mg and carbidopa and levodopa tablets 10 mg/100 mg). Tablets of the two ratios may be given separately or combined as needed to provide the optimum dosage.

Studies show that peripheral dopa decarboxylase is saturated by carbidopa at approximately 70 to 100 mg a day. Patients receiving less than this amount of carbidopa are more likely to experience nausea and vomiting.

Usual Initial Dosage
Dosage is best initiated with one tablet of carbidopa and levodopa tablets 25 mg/100 mg three times a day. This dosage schedule provides 75 mg of carbidopa per day. Dosage may be increased by one tablet every day or every other day, as necessary, until a dosage of eight tablets of carbidopa and levodopa tablets 25 mg/100 mg a day is reached.

If carbidopa and levodopa tablets 10 mg/100 mg are used, dosage may be initiated with one tablet three or four times a day. However, this will not provide an adequate amount of carbidopa for many patients. Dosage may be increased by one tablet every day or every other day until a total of eight tablets (2 tablets q.i.d.) is reached.

How to Transfer Patients from Levodopa
Levodopa must be discontinued at least twelve hours before starting carbidopa and levodopa tablets. A daily dosage of carbidopa and levodopa should be chosen that will provide approximately 25% of the previous levodopa dosage. Patients who are taking less than 1500 mg of levodopa a day should be started on one tablet of carbidopa and levodopa 25 mg/100 mg three or four times a day. The suggested starting dosage for most patients taking more than 1500 mg of levodopa is one tablet of carbidopa and levodopa 25 mg/250 mg three or four times a day.

Maintenance
Therapy should be individualized and adjusted according to the desired therapeutic response. At least 70 to 100 mg of carbidopa per day should be provided. When a greater proportion of carbidopa is required, one tablet of carbidopa and levodopa 25 mg/100 mg may be substituted for each tablet of carbidopa and levodopa 10 mg/100 mg. When more levodopa is required, carbidopa and levodopa tablets 25 mg/250 mg should be substituted for carbidopa and levodopa tablets 25 mg/100 mg or carbidopa and levodopa tablets 10 mg/100 mg. If necessary, the dosage of carbidopa and levodopa tablets 25 mg/250 mg may be increased by one-half or one tablet every day or every other day to a maximum of eight tablets a day. Experience with total daily dosages of carbidopa greater than 200 mg is limited.

Because both therapeutic and adverse responses occur more rapidly with carbidopa and levodopa than with levodopa alone, patients should be monitored closely during the dose adjustment period. Specifically, involuntary movements will occur more rapidly with carbidopa and levodopa than with levodopa. The occurrence of involuntary movements may require dosage reduction. Blepharospasm may be a useful early sign of excess dosage in some patients.

Addition of Other Antiparkinsonian Medications
Standard drugs for Parkinson's disease, other than levodopa without a decarboxylase inhibitor, may be used concomitantly while carbidopa and levodopa tablets are being administered, although dosage adjustments may be required.

Interruption of Therapy
Sporadic cases of a symptom complex resembling Neuroleptic Malignant Syndrome (NMS) have been associated with dose reductions and withdrawal of carbidopa and levodopa tablets. Patients should be observed carefully if abrupt reduction or discontinuation of carbidopa and levodopa tablets is required, especially if the patient is receiving neuroleptics (See WARNINGS).

If general anesthesia is required, carbidopa and levodopa may be continued as long as the patient is permitted to take fluids and medication by mouth. If therapy is interrupted temporarily, the patient should be observed for symptoms resembling NMS, and the usual daily dosage may be administered as soon as the patient is able to take oral medication.

The optimum daily dosage of carbidopa and levodopa must be determined by careful titration in each patient. Carbidopa and levodopa tablets are available in a 1:4 ratio of carbidopa to levodopa (25 mg/100 mg) as well as 1:10 ratio (25 mg/250 mg and 10 mg/100 mg). Tablets of the two ratios may be given separately or combined as needed to provide the optimum dosage.

Studies show that peripheral dopa decarboxylase is saturated by carbidopa at approximately 70 to 100 mg a day. Patients receiving less than this amount of carbidopa are more likely to experience nausea and vomiting.

Usual Initial Dosage: Dosage is best initiated with one tablet of carbidopa and levodopa

25 mg/100 mg three times a day. This dosage schedule provides 75 mg of carbidopa per day. Dosage may be increased by one tablet every day or every other day, as necessary, until a dosage of eight tablets of carbidopa and levodopa 25 mg/100 mg a day is reached.

If carbidopa and levodopa 10 mg/100 mg is used, dosage may be initiated with one tablet three or four times a day. However, this will not provide an adequate amount of carbidopa for many patients. Dosage may be increased by one tablet every day or every other day until a total of eight tablets (2 tablets q.i.d.) is reached.

How To Transfer Patients From Levodopa: Levodopa must be discontinued at least twelve hours before starting this combination product. A daily dosage of carbidopa and levodopa should be chosen that will provide approximately 25% of the previous levodopa dosage. Patients who are taking less than 1500 mg of levodopa a day should be started on one tablet of carbidopa and levodopa 25 mg/100 mg three or four times a day. The suggested starting dosage for most patients taking more than 1500 mg of levodopa is one tablet of carbidopa and levodopa 25 mg/250 mg three or four times a day.

Maintenance: Therapy should be individualized and adjusted according to the desired therapeutic response. At least 70 to 100 mg of carbidopa per day should be provided. When a greater proportion of carbidopa is required, one 25 mg/100 mg tablet may be substituted for each 10 mg/100 mg tablet. When more levodopa is required, each 25 mg/250 mg tablet should be substituted for a 25 mg/100 mg tablet or a 10 mg/100 mg tablet. If necessary, the dosage of carbidopa and levodopa 25 mg/250 mg may be increased by one-half or one tablet every day or every other day to a maximum of eight tablets a day. Experience with total daily dosages of carbidopa greater than 200 mg is limited.

Because both therapeutic and adverse responses occur more rapidly with this combination product than with levodopa alone, patients should be monitored closely during the dose adjustment period. Specifically, involuntary movements will occur more rapidly with carbidopa and levodopa than with levodopa. The occurrence of involuntary movements may require dosage reduction. Blepharospasm may be a useful early sign of excess dosage in some patients.

Addition Of Other Antiparkinsonian Medications: Standard drugs for Parkinson's disease, other than levodopa without a decarboxylase inhibitor, may be used concomitantly while carbidopa and levodopa is being administered, although dosage adjustments may be required.

Interruption Of Therapy: Sporadic cases of a symptom complex resembling Neuroleptic Malignant Syndrome (NMS) have been associated with dose reductions and withdrawal of carbidopa and levodopa. Patients should be observed carefully if abrupt reduction or discontinuation of carbidopa and levodopa is required, especially if the patient is receiving neuroleptics. (See WARNINGS.)

If general anesthesia is required, carbidopa and levodopa may be continued as long as the patient is permitted to take fluids and medication by mouth. If therapy is interrupted temporarily, the patient should be observed for symptoms resembling NMS, and the usual daily dosage may be administered as soon as the patient is able to take oral medication.

Weeks 1 to 6

Weeks 7 to 9

Weeks 10 to 12

1 piece every 1 to 2 hours

1 piece every 2 to 4 hours

1 piece every 4 to 8 hours

Just prior to administration, GENTLY remove the tablet from the bottle with dry hands. IMMEDIATELY place the carbidopa and levodopa orally disintegrating tablet on top of the tongue where it will dissolve in seconds, then swallow with saliva. Administration with liquid is not necessary.

The optimum daily dosage of carbidopa and levodopa orally disintegrating tablets must be determined by careful titration in each patient. Carbidopa and levodopa orally disintegrating tablets are available in a 1:4 ratio of carbidopa to levodopa (carbidopa and levodopa orally disintegrating tablets 25 mg/100 mg) as well as 1:10 ratio (carbidopa and levodopa orally disintegrating tablets 25 mg/250 mg and carbidopa and levodopa orally disintegrating tablets 10 mg/100 mg). Tablets of the two ratios may be given separately or combined as needed to provide the optimum dosage.

Studies show that peripheral dopa decarboxylase is saturated by carbidopa at approximately 70 mg to 100 mg a day. Patients receiving less than this amount of carbidopa are more likely to experience nausea and vomiting.

Dosage is best initiated with one carbidopa and levodopa orally disintegrating tablet 25 mg/100 mg 3 times a day. This dosage schedule provides 75 mg of carbidopa per day. Dosage may be increased by one tablet every day or every other day, as necessary, until a dosage of eight carbidopa and levodopa orally disintegrating tablets 25 mg/100 mg a day is reached.

If carbidopa and levodopa orally disintegrating tablets 10 mg/100 mg are used, dosage may be initiated with one tablet 3 or 4 times a day. However, this will not provide an adequate amount of carbidopa for many patients. Dosage may be increased by one tablet every day or every other day until a total of eight tablets (two tablets q.i.d.) is reached.

Levodopa must be discontinued at least twelve hours before starting carbidopa and levodopa orally disintegrating tablets. A daily dosage of carbidopa and levodopa orally disintegrating tablets should be chosen that will provide approximately 25 percent of the previous levodopa dosage. Patients who are taking less than 1500 mg of levodopa a day should be started on one carbidopa and levodopa orally disintegrating tablet 25 mg/100 mg 3 or 4 times a day. The suggested starting dosage for most patients taking more than 1500 mg of levodopa is one carbidopa and levodopa orally disintegrating tablet 25 mg/250 mg 3 or 4 times a day.

Therapy should be individualized and adjusted according to the desired therapeutic response. At least 70 mg to 100 mg of carbidopa per day should be provided. When a greater proportion of carbidopa is required, one carbidopa and levodopa orally disintegrating tablet 25 mg/100 mg may be substituted for each carbidopa and levodopa orally disintegrating tablet 10 mg/100 mg. When more levodopa is required, carbidopa and levodopa orally disintegrating 25 mg/250 mg tablets should be substituted for carbidopa and levodopa orally disintegrating 25 mg/100 mg tablets or carbidopa and levodopa orally disintegrating 10 mg/100 mg tablets. If necessary, the dosage of carbidopa and levodopa orally disintegrating tablet 25 mg/250 mg tablets may be increased by one-half or one tablet every day or every other day to a maximum of eight tablets a day. Experience with total daily dosages of carbidopa greater than 200 mg is limited.

Because both therapeutic and adverse responses occur more rapidly with carbidopa and levodopa orally disintegrating tablets than with levodopa alone, patients should be monitored closely during the dose adjustment period. Specifically, involuntary movements will occur more rapidly with carbidopa and levodopa orally disintegrating tablets than with levodopa. The occurrence of involuntary movements may require dosage reduction. Blepharospasm may be a useful early sign of excess dosage in some patients.

Standard drugs for Parkinson's disease, other than levodopa without a decarboxylase inhibitor, may be used concomitantly while carbidopa and levodopa orally disintegrating tablets are being administered, although dosage adjustments may be required.

Sporadic cases of a symptom complex resembling Neuroleptic Malignant Syndrome (NMS) have been associated with dose reductions and withdrawal of carbidopa and levodopa. Patients should be observed carefully if abrupt reduction or discontinuation of carbidopa and levodopa orally disintegrating tablets is required, especially if the patient is receiving neuroleptics. (See WARNINGS.)

If general anesthesia is required, carbidopa and levodopa orally disintegrating tablets may be continued as long as the patient is permitted to take fluids and medication by mouth. If therapy is interrupted temporarily, the patient should be observed for symptoms resembling NMS, and the usual daily dosage may be administered as soon as the patient is able to take oral medication.

The optimum daily dosage of carbidopa and levodopa must be determined by careful titration in each patient. Carbidopa and levodopa tablets are available in a 1:4 ratio of carbidopa to levodopa (25 mg/100 mg) as well as 1:10 ratio (25 mg/250 mg and 10 mg/100 mg). Tablets of the two ratios may be given separately or combined as needed to provide the optimum dosage.

Studies show that peripheral dopa decarboxylase is saturated by carbidopa at approximately 70 to 100 mg a day. Patients receiving less than this amount of carbidopa are more likely to experience nausea and vomiting.

Usual Initial Dosage: Dosage is best initiated with one tablet of carbidopa and levodopa

25 mg/100 mg three times a day. This dosage schedule provides 75 mg of carbidopa per day. Dosage may be increased by one tablet every day or every other day, as necessary, until a dosage of eight tablets of carbidopa and levodopa 25 mg/100 mg a day is reached.

If carbidopa and levodopa 10 mg/100 mg is used, dosage may be initiated with one tablet three or four times a day. However, this will not provide an adequate amount of carbidopa for many patients. Dosage may be increased by one tablet every day or every other day until a total of eight tablets (2 tablets q.i.d.) is reached.

How To Transfer Patients From Levodopa: Levodopa must be discontinued at least twelve hours before starting this combination product. A daily dosage of carbidopa and levodopa should be chosen that will provide approximately 25% of the previous levodopa dosage. Patients who are taking less than 1500 mg of levodopa a day should be started on one tablet of carbidopa and levodopa 25 mg/100 mg three or four times a day. The suggested starting dosage for most patients taking more than 1500 mg of levodopa is one tablet of carbidopa and levodopa 25 mg/250 mg three or four times a day.

Maintenance: Therapy should be individualized and adjusted according to the desired therapeutic response. At least 70 to 100 mg of carbidopa per day should be provided. When a greater proportion of carbidopa is required, one 25 mg/100 mg tablet may be substituted for each 10 mg/100 mg tablet. When more levodopa is required, each 25 mg/250 mg tablet should be substituted for a 25 mg/100 mg tablet or a 10 mg/100 mg tablet. If necessary, the dosage of carbidopa and levodopa 25 mg/250 mg may be increased by one-half or one tablet every day or every other day to a maximum of eight tablets a day. Experience with total daily dosages of carbidopa greater than 200 mg is limited.

Because both therapeutic and adverse responses occur more rapidly with this combination product than with levodopa alone, patients should be monitored closely during the dose adjustment period. Specifically, involuntary movements will occur more rapidly with carbidopa and levodopa than with levodopa. The occurrence of involuntary movements may require dosage reduction. Blepharospasm may be a useful early sign of excess dosage in some patients.

Addition Of Other Antiparkinsonian Medications: Standard drugs for Parkinson's disease, other than levodopa without a decarboxylase inhibitor, may be used concomitantly while carbidopa and levodopa is being administered, although dosage adjustments may be required.

Interruption Of Therapy: Sporadic cases of a symptom complex resembling Neuroleptic Malignant Syndrome (NMS) have been associated with dose reductions and withdrawal of carbidopa and levodopa. Patients should be observed carefully if abrupt reduction or discontinuation of carbidopa and levodopa is required, especially if the patient is receiving neuroleptics. (See WARNINGS.)

If general anesthesia is required, carbidopa and levodopa may be continued as long as the patient is permitted to take fluids and medication by mouth. If therapy is interrupted temporarily, the patient should be observed for symptoms resembling NMS, and the usual daily dosage may be administered as soon as the patient is able to take oral medication.

The optimum daily dosage of carbidopa and levodopa must be determined by careful titration in each patient. Carbidopa and levodopa tablets are available in a 1:4 ratio of carbidopa to levodopa (25 mg/100 mg) as well as 1:10 ratio (25 mg/250 mg and 10 mg/100 mg). Tablets of the two ratios may be given separately or combined as needed to provide the optimum dosage.

Studies show that peripheral dopa decarboxylase is saturated by carbidopa at approximately 70 to 100 mg a day. Patients receiving less than this amount of carbidopa are more likely to experience nausea and vomiting.

Usual Initial Dosage: Dosage is best initiated with one tablet of carbidopa and levodopa

25 mg/100 mg three times a day. This dosage schedule provides 75 mg of carbidopa per day. Dosage may be increased by one tablet every day or every other day, as necessary, until a dosage of eight tablets of carbidopa and levodopa 25 mg/100 mg a day is reached.

If carbidopa and levodopa 10 mg/100 mg is used, dosage may be initiated with one tablet three or four times a day. However, this will not provide an adequate amount of carbidopa for many patients. Dosage may be increased by one tablet every day or every other day until a total of eight tablets (2 tablets q.i.d.) is reached.

How To Transfer Patients From Levodopa: Levodopa must be discontinued at least twelve hours before starting this combination product. A daily dosage of carbidopa and levodopa should be chosen that will provide approximately 25% of the previous levodopa dosage. Patients who are taking less than 1500 mg of levodopa a day should be started on one tablet of carbidopa and levodopa 25 mg/100 mg three or four times a day. The suggested starting dosage for most patients taking more than 1500 mg of levodopa is one tablet of carbidopa and levodopa 25 mg/250 mg three or four times a day.

Maintenance: Therapy should be individualized and adjusted according to the desired therapeutic response. At least 70 to 100 mg of carbidopa per day should be provided. When a greater proportion of carbidopa is required, one 25 mg/100 mg tablet may be substituted for each 10 mg/100 mg tablet. When more levodopa is required, each 25 mg/250 mg tablet should be substituted for a 25 mg/100 mg tablet or a 10 mg/100 mg tablet. If necessary, the dosage of carbidopa and levodopa 25 mg/250 mg may be increased by one-half or one tablet every day or every other day to a maximum of eight tablets a day. Experience with total daily dosages of carbidopa greater than 200 mg is limited.

Because both therapeutic and adverse responses occur more rapidly with this combination product than with levodopa alone, patients should be monitored closely during the dose adjustment period. Specifically, involuntary movements will occur more rapidly with carbidopa and levodopa than with levodopa. The occurrence of involuntary movements may require dosage reduction. Blepharospasm may be a useful early sign of excess dosage in some patients.

Addition Of Other Antiparkinsonian Medications: Standard drugs for Parkinson's disease, other than levodopa without a decarboxylase inhibitor, may be used concomitantly while carbidopa and levodopa is being administered, although dosage adjustments may be required.

Interruption Of Therapy: Sporadic cases of a symptom complex resembling Neuroleptic Malignant Syndrome (NMS) have been associated with dose reductions and withdrawal of carbidopa and levodopa. Patients should be observed carefully if abrupt reduction or discontinuation of carbidopa and levodopa is required, especially if the patient is receiving neuroleptics. (See WARNINGS.)

If general anesthesia is required, carbidopa and levodopa may be continued as long as the patient is permitted to take fluids and medication by mouth. If therapy is interrupted temporarily, the patient should be observed for symptoms resembling NMS, and the usual daily dosage may be administered as soon as the patient is able to take oral medication.

Carbidopa and levodopa extended-release tablet contains carbidopa and levodopa in a 1:4 ratio as either the 50 mg/200 mg tablet or the 25 mg/100 mg tablet. The daily dosage of carbidopa and levodopa extended-release tablets must be determined by careful titration. Patients should be monitored closely during the dose adjustment period, particularly with regard to appearance or worsening of involuntary movements, dyskinesias or nausea. Carbidopa and levodopa extended-release tablets should not be chewed or crushed.
Standard drugs for Parkinson's disease, other than levodopa without a decarboxylase inhibitor, may be used concomitantly while carbidopa and levodopa extended-release tablet is being administered, although their dosage may have to be adjusted.
Since carbidopa prevents the reversal of levodopa effects caused by pyridoxine, carbidopa and levodopa extended-release tablets can be given to patients receiving supplemental pyridoxine (vitamin B6).

Patients currently treated with conventional carbidopa and levodopa preparations:
Studies show that peripheral dopa-decarboxylase is saturated by the bioavailable carbidopa at doses of 70 mg a day and greater. Because the bioavailabilities of carbidopa and levodopa in carbidopa and levodopa tablets and carbidopa and levodopa extended-release tablets are different, appropriate adjustments should be made, as shown in Table 2.

Dosage with carbidopa and levodopa extended-release tablets should be substituted at an amount that provides approximately 10% more levodopa per day, although this may need to be increased to a dosage that provides up to 30% more levodopa per day depending on clinical response (see DOSAGE AND ADMINISTRATION, Titration with carbidopa and levodopa extended-release tablets). The interval between doses of carbidopa and levodopa extended-release tablets should be 4 to 8 hours during the waking day. (See CLINICAL PHARMACOLOGY, Pharmacodynamics.)
A guideline for initiation of carbidopa and levodopa extended-release tablets is shown in Table 3.

Patients currently treated with levodopa without a decarboxylase inhibitor:
Levodopa must be discontinued at least twelve hours before therapy with carbidopa and levodopa extended-release tablets is started. Carbidopa and levodopa extended-release tablets should be substituted at a dosage that will provide approximately 25% of the previous levodopa dosage. In patients with mild to moderate disease, the initial dose is usually 1 tablet of carbidopa and levodopa extended-release tablets 50 mg/200 mg b.i.d.
Patients not receiving levodopa:
In patients with mild to moderate disease, the initial recommended dose is 1 tablet of carbidopa and levodopa extended-release tablets 50 mg/200 mg b.i.d. Initial dosage should not be given at intervals of less than 6 hours.

Following initiation of therapy, doses and dosing intervals may be increased or decreased depending upon therapeutic response. Most patients have been adequately treated with doses of carbidopa and levodopa extended-release tablets that provide 400 to 1,600 mg of levodopa per day, administered as divided doses at intervals ranging from 4 to 8 hours during the waking day. Higher doses of carbidopa and levodopa extended-release tablets (2,400 mg or more of levodopa per day) and shorter intervals (less than 4 hours) have been used, but are not usually recommended.
When doses of carbidopa and levodopa extended-release tablets are given at intervals of less than 4 hours, and/or if the divided doses are not equal, it is recommended that the smaller doses be given at the end of the day.
An interval of at least 3 days between dosage adjustments is recommended.

Because Parkinson's disease is progressive, periodic clinical evaluations are recommended; adjustment of the dosage regimen of carbidopa and levodopa extended-release tablets may be required.

Anticholinergic agents, dopamine agonists, and amantadine can be given with carbidopa and levodopa extended-release tablets. Dosage adjustment of carbidopa and levodopa extended-release tablets may be necessary when these agents are added.

A dose of carbidopa and levodopa tablets  25 mg/100 mg or 10 mg/100 mg (one half or a whole tablet) can be added to the dosage regimen of carbidopa and levodopa extended-release tablets in selected patients with advanced disease who need additional immediate-release levodopa for a brief time during daytime hours.

Sporadic cases of hyperpyrexia and confusion have been associated with dose reductions and withdrawal of carbidopa and levodopa tablets or carbidopa and levodopa extended-release tablets.
Patients should be observed carefully if abrupt reduction or discontinuation of carbidopa and levodopa extended-release tablets is required, especially if the patient is receiving neuroleptics. (See WARNINGS).
If general anesthesia is required, carbidopa and levodopa extended-release tablets may be continued as long as the patient is permitted to take oral medication. If therapy is interrupted temporarily, the patient should be observed for symptoms resembling NMS, and the usual dosage should be administered as soon as the patient is able to take oral medication.

The optimum daily dosage of carbidopa and levodopa tablets USP must be determined by careful titration in each patient. Carbidopa and levodopa tablets USP are available in a 1:4 ratio of carbidopa to levodopa (25 mg/100 mg) as well as a 1:10 ratio (25 mg/250 mg and 10 mg/100 mg). Tablets of the two ratios may be given separately or combined as needed to provide the optimum dosage.

Studies show that peripheral dopa decarboxylase is saturated by carbidopa at approximately 70 to 100 mg a day. Patients receiving less than this amount of carbidopa are more likely to experience nausea and vomiting.

Dosage is best initiated with one carbidopa and levodopa tablet USP, 25 mg/100 mg three times a day. This dosage schedule provides 75 mg of carbidopa per day. Dosage may be increased by one tablet every day or every other day, as necessary, until a dosage of eight carbidopa and levodopa tablets USP, 25 mg/100 mg a day is reached.

If carbidopa and levodopa tablets USP, 10 mg/100 mg are used, dosage may be initiated with one tablet three or four times a day. However, this will not provide an adequate amount of carbidopa for many patients. Dosage may be increased by one tablet every day or every other day until a total of eight tablets (2 tablets q.i.d.) is reached.

Levodopa must be discontinued at least twelve hours before starting this combination product. A daily dosage of carbidopa and levodopa tablets USP should be chosen that will provide approximately 25% of the previous levodopa dosage. Patients who are taking less than 1500 mg of levodopa a day should be started on one carbidopa and levodopa tablet USP, 25 mg/100 mg three or four times a day. The suggested starting dosage for most patients taking more than 1500 mg of levodopa is one carbidopa and levodopa tablet USP, 25 mg/250 mg three or four times a day.

Therapy should be individualized and adjusted according to the desired therapeutic response. At least 70 to 100 mg of carbidopa per day should be provided. When a greater proportion of carbidopa is required, one carbidopa and levodopa tablet USP, 25 mg/100 mg may be substituted for each carbidopa and levodopa tablet USP, 10 mg/100 mg. When more levodopa is required, each carbidopa and levodopa tablet USP, 25 mg/250 mg should be substituted for a carbidopa and levodopa tablet USP, 25 mg/100 mg or a carbidopa and levodopa tablet USP, 10 mg/100 mg. If necessary, the dosage of carbidopa and levodopa tablets USP, 25 mg/250 mg may be increased by one-half or one tablet every day or every other day to a maximum of eight tablets a day. Experience with total daily dosages of carbidopa greater than 200 mg is limited.

Because both therapeutic and adverse responses occur more rapidly with this combination product than with levodopa alone, patients should be monitored closely during the dose adjustment period. Specifically, involuntary movements will occur more rapidly with carbidopa and levodopa than with levodopa. The occurrence of involuntary movements may require dosage reduction. Blepharospasm may be a useful early sign of excess dosage in some patients.

Standard drugs for Parkinson’s disease, other than levodopa without a decarboxylase inhibitor, may be used concomitantly while carbidopa and levodopa therapy is being administered, although dosage adjustments may be required.

Sporadic cases of a symptom complex resembling Neuroleptic Malignant Syndrome (NMS) have been associated with dose reductions and withdrawal of carbidopa and levodopa tablets USP. Patients should be observed carefully if abrupt reduction or discontinuation of carbidopa and levodopa tablets USP is required, especially if the patient is receiving neuroleptics (see WARNINGS).

If general anesthesia is required, carbidopa and levodopa therapy may be continued as long as the patient is permitted to take fluids and medication by mouth. If therapy is interrupted temporarily, the patient should be observed for symptoms resembling NMS, and the usual daily dosage may be administered as soon as the patient is able to take oral medication.

Carbidopa and levodopa extended-release tablets contain carbidopa and levodopa in a 1:4 ratio as either the 50 mg/200 mg tablet or the 25 mg/100 mg tablet. The daily dosage of carbidopa and levodopa extended-release tablets must be determined by careful titration. Patients should be monitored closely during the dose adjustment period, particularly with regard to appearance or worsening of involuntary movements, dyskinesias or nausea. Carbidopa and levodopa extended-release tablets should not be chewed or crushed.

Standard drugs for Parkinson’s disease, other than levodopa without a decarboxylase inhibitor, may be used concomitantly while carbidopa and levodopa extended-release tablets are being administered, although their dosage may have to be adjusted.

Since carbidopa prevents the reversal of levodopa effects caused by pyridoxine, carbidopa and levodopa extended-release tablets can be given to patients receiving supplemental pyridoxine (vitamin B6).

Studies show that peripheral dopa-decarboxylase is saturated by the bioavailable carbidopa at doses of 70 mg a day and greater. Because the bioavailabilities of carbidopa and levodopa in carbidopa and levodopa immediate-release tablets and carbidopa and levodopa extended-release tablets are different, appropriate adjustments should be made, as shown in Table 2.

Tablet

Amount of Levodopa
(mg) in Each Tablet

Approximate
Bioavailability

Approximate Amount
of Bioavailable Levodopa
(mg) in Each Tablet

Carbidopa and Levodopa
Extended-release Tablets
50 mg/200 mg

200

0.70 to 0.75†

140 to 150

Carbidopa and Levodopa
Immediate-release Tablets
25 mg/100 mg

100

0.99‡

99

Dosage with carbidopa and levodopa extended-release tablets should be substituted at an amount that provides approximately 10% more levodopa per day, although this may need to be increased to a dosage that provides up to 30% more levodopa per day depending on clinical response (see DOSAGE AND ADMINISTRATION: Titration with Carbidopa and Levodopa Extended-release Tablets). The interval between doses of carbidopa and levodopa extended-release tablets should be 4 to 8 hours during the waking day (see CLINICAL PHARMACOLOGY: Pharmacodynamics).

A guideline for initiation of carbidopa and levodopa extended-release tablets is shown in Table 3.

Carbidopa and Levodopa Immediate-release Tablets

Carbidopa and Levodopa Extended-release Tablets

Total Daily Dose* Levodopa (mg)

Suggested Dosage Regimen

300–400

200 mg b.i.d.

500–600

300 mg b.i.d. or
200 mg t.i.d.

700–800

A total of 800 mg in 3 or more divided doses (e.g., 300 mg a.m., 300 mg early p.m. and 200 mg later p.m.)

900–1000

A total of 1000 mg in 3 or more divided doses (e.g., 400 mg a.m., 400 mg early p.m., and 200 mg later p.m.)

Levodopa must be discontinued at least 12 hours before therapy with carbidopa and levodopa extended-release tablets is started. Carbidopa and levodopa extended-release tablets should be substituted at a dosage that will provide approximately 25% of the previous levodopa dosage. In patients with mild to moderate disease, the initial dose is usually one tablet of 50 mg/200 mg carbidopa and levodopa extended-release tablets b.i.d.

In patients with mild to moderate disease, the initial recommended dose is one tablet of 50 mg/200 mg carbidopa and levodopa extended-release tablets b.i.d. Initial dosage should not be given at intervals of less than 6 hours.

Following initiation of therapy, doses and dosing intervals may be increased or decreased depending upon therapeutic response. Most patients have been adequately treated with doses of carbidopa and levodopa extended-release tablets that provide 400 mg to 1600 mg of levodopa per day, administered as divided doses at intervals ranging from 4 to 8 hours during the waking day. Higher doses of carbidopa and levodopa extended-release tablets (2400 mg or more of levodopa per day) and shorter intervals (less than 4 hours) have been used, but are not usually recommended.

When doses of carbidopa and levodopa extended-release tablets are given at intervals of less than 4 hours, and/or if the divided doses are not equal, it is recommended that the smaller doses be given at the end of the day.

An interval of at least 3 days between dosage adjustments is recommended.

Because Parkinson's disease is progressive, periodic clinical evaluations are recommended; adjustment of the dosage regimen of carbidopa and levodopa extended-release tablets may be required.

Anticholinergic agents, dopamine agonists, and amantadine can be given with carbidopa and levodopa extended-release tablets. Dosage adjustment of carbidopa and levodopa extended-release tablets may be necessary when these agents are added.

A dose of carbidopa and levodopa immediate-release tablets 25 mg/100 mg or 10 mg/100 mg (one half or a whole tablet) can be added to the dosage regimen of carbidopa and levodopa extended-release tablets in selected patients with advanced disease who need additional immediate-release levodopa for a brief time during daytime hours.

Sporadic cases of hyperpyrexia and confusion have been associated with dose reductions and withdrawal of carbidopa and levodopa immediate-release tablets or carbidopa and levodopa extended-release tablets.

Patients should be observed carefully if abrupt reduction or discontinuation of carbidopa and levodopa extended-release tablets is required, especially if the patient is receiving neuroleptics (see WARNINGS).

If general anesthesia is required, carbidopa and levodopa extended-release tablets may be continued as long as the patient is permitted to take oral medication. If therapy is interrupted temporarily, the patient should be observed for symptoms resembling NMS, and the usual dosage should be administered as soon as the patient is able to take oral medication.

The optimum daily dosage of carbidopa and levodopa tablets must be determined by careful titration in each patient. Carbidopa and levodopa tablets are available in a 1:4 ratio of carbidopa to levodopa (carbidopa and levodopa tablets 25 mg/100 mg) as well as 1:10 ratio (carbidopa and levodopa tablets 25 mg/250 mg and carbidopa and levodopa tablets 10 mg/100 mg). Tablets of the two ratios may be given separately or combined as needed to provide the optimum dosage.

Studies show that peripheral dopa decarboxylase is saturated by carbidopa at approximately 70 mg to 100 mg a day. Patients receiving less than this amount of carbidopa are more likely to experience nausea and vomiting.

Dosage is best initiated with one tablet of carbidopa and levodopa 25 mg/100 mg 3 times a day. This dosage schedule provides 75 mg of carbidopa per day. Dosage may be increased by one tablet every day or every other day, as necessary, until a dosage of eight tablets of carbidopa and levodopa 25 mg/100 mg a day is reached.

If carbidopa and levodopa 10 mg/100 mg is used, dosage may be initiated with one tablet 3 or 4 times a day. However, this will not provide an adequate amount of carbidopa for many patients. Dosage may be increased by one tablet every day or every other day until a total of eight tablets (two tablets q.i.d.) is reached.

Levodopa must be discontinued at least 12 hours before starting carbidopa and levodopa tablets. A daily dosage of carbidopa and levodopa should be chosen that will provide approximately 25% of the previous levodopa dosage. Patients who are taking less than 1500 mg of levodopa a day should be started on one tablet of carbidopa and levodopa 25 mg/100 mg 3 or 4 times a day. The suggested starting dosage for most patients taking more than 1500 mg of levodopa is one tablet of carbidopa and levodopa 25 mg/250 mg 3 or 4 times a day.

Therapy should be individualized and adjusted according to the desired therapeutic response. At least 70 mg to 100 mg of carbidopa per day should be provided. When a greater proportion of carbidopa is required, one tablet of carbidopa and levodopa 25 mg/100 mg may be substituted for each tablet of carbidopa and levodopa 10 mg/100 mg. When more levodopa is required, carbidopa and levodopa 25 mg/250 mg should be substituted for carbidopa and levodopa 25 mg/100 mg or carbidopa and levodopa 10 mg/100 mg. If necessary, the dosage of carbidopa and levodopa 25 mg/250 mg may be increased by one-half or one tablet every day or every other day to a maximum of eight tablets a day. Experience with total daily dosages of carbidopa greater than 200 mg is limited.

Because both therapeutic and adverse responses occur more rapidly with carbidopa and levodopa than with levodopa alone, patients should be monitored closely during the dose adjustment period. Specifically, involuntary movements will occur more rapidly with carbidopa and levodopa than with levodopa. The occurrence of involuntary movements may require dosage reduction. Blepharospasm may be a useful early sign of excess dosage in some patients.

Standard drugs for Parkinson's disease, other than levodopa without a decarboxylase inhibitor, may be used concomitantly while carbidopa and levodopa tablets are being administered, although dosage adjustments may be required.

Sporadic cases of a symptom complex resembling Neuroleptic Malignant Syndrome (NMS) have been associated with dose reductions and withdrawal of carbidopa and levodopa. Patients should be observed carefully if abrupt reduction or discontinuation of carbidopa and levodopa is required, especially if the patient is receiving neuroleptics. (See WARNINGS.)

If general anesthesia is required, carbidopa and levodopa tablets may be continued as long as the patient is permitted to take fluids and medication by mouth. If therapy is interrupted temporarily, the patient should be observed for symptoms resembling NMS and the usual daily dosage may be administered as soon as the patient is able to take oral medication.

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Acne Treatment Gel

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The optimum daily dosage of carbidopa and levodopa tablets USP must be determined by careful titration in each patient. Carbidopa and levodopa tablets USP are available in a 1:4 ratio of carbidopa to levodopa (25 mg/100 mg) as well as a 1:10 ratio (25 mg/250 mg and 10 mg/100 mg). Tablets of the two ratios may be given separately or combined as needed to provide the optimum dosage.

Studies show that peripheral dopa decarboxylase is saturated by carbidopa at approximately 70 to 100 mg a day. Patients receiving less than this amount of carbidopa are more likely to experience nausea and vomiting.

Dosage is best initiated with one carbidopa and levodopa tablet USP, 25 mg/100 mg three times a day. This dosage schedule provides 75 mg of carbidopa per day. Dosage may be increased by one tablet every day or every other day, as necessary, until a dosage of eight carbidopa and levodopa tablets USP, 25 mg/100 mg a day is reached.

If carbidopa and levodopa tablets USP, 10 mg/100 mg are used, dosage may be initiated with one tablet three or four times a day. However, this will not provide an adequate amount of carbidopa for many patients. Dosage may be increased by one tablet every day or every other day until a total of eight tablets (2 tablets q.i.d.) is reached.

Levodopa must be discontinued at least twelve hours before starting this combination product. A daily dosage of carbidopa and levodopa tablets USP should be chosen that will provide approximately 25% of the previous levodopa dosage. Patients who are taking less than 1500 mg of levodopa a day should be started on one carbidopa and levodopa tablet USP, 25 mg/100 mg three or four times a day. The suggested starting dosage for most patients taking more than 1500 mg of levodopa is one carbidopa and levodopa tablet USP, 25 mg/250 mg three or four times a day.

Therapy should be individualized and adjusted according to the desired therapeutic response. At least 70 to 100 mg of carbidopa per day should be provided. When a greater proportion of carbidopa is required, one carbidopa and levodopa tablet USP, 25 mg/100 mg may be substituted for each carbidopa and levodopa tablet USP, 10 mg/100 mg. When more levodopa is required, each carbidopa and levodopa tablet USP, 25 mg/250 mg should be substituted for a carbidopa and levodopa tablet USP, 25 mg/100 mg or a carbidopa and levodopa tablet USP, 10 mg/100 mg. If necessary, the dosage of carbidopa and levodopa tablets USP, 25 mg/250 mg may be increased by one-half or one tablet every day or every other day to a maximum of eight tablets a day. Experience with total daily dosages of carbidopa greater than 200 mg is limited.

Because both therapeutic and adverse responses occur more rapidly with this combination product than with levodopa alone, patients should be monitored closely during the dose adjustment period. Specifically, involuntary movements will occur more rapidly with carbidopa and levodopa than with levodopa. The occurrence of involuntary movements may require dosage reduction. Blepharospasm may be a useful early sign of excess dosage in some patients.

Standard drugs for Parkinson’s disease, other than levodopa without a decarboxylase inhibitor, may be used concomitantly while carbidopa and levodopa therapy is being administered, although dosage adjustments may be required.

Sporadic cases of a symptom complex resembling Neuroleptic Malignant Syndrome (NMS) have been associated with dose reductions and withdrawal of carbidopa and levodopa tablets USP. Patients should be observed carefully if abrupt reduction or discontinuation of carbidopa and levodopa tablets USP is required, especially if the patient is receiving neuroleptics (see WARNINGS).

If general anesthesia is required, carbidopa and levodopa therapy may be continued as long as the patient is permitted to take fluids and medication by mouth. If therapy is interrupted temporarily, the patient should be observed for symptoms resembling NMS, and the usual daily dosage may be administered as soon as the patient is able to take oral medication.

The optimum daily dosage of carbidopa and levodopa tablets USP must be determined by careful titration in each patient. Carbidopa and levodopa tablets USP are available in a 1:4 ratio of carbidopa to levodopa (25 mg/100 mg) as well as 1:10 ratio (25 mg/250 mg and 10 mg/100 mg). Tablets of the two ratios may be given separately or combined as needed to provide the optimum dosage.

Studies show that peripheral dopa decarboxylase is saturated by carbidopa at approximately 70 to 100 mg a day. Patients receiving less than this amount of carbidopa are more likely to experience nausea and vomiting.

Dosage is best initiated with one carbidopa and levodopa tablet USP, 25 mg/100 mg three times a day. This dosage schedule provides 75 mg of carbidopa per day. Dosage may be increased by one tablet every day or every other day, as necessary, until a dosage of eight carbidopa and levodopa tablets USP, 25 mg/100 mg a day is reached.

If carbidopa and levodopa tablets USP, 10 mg/100 mg are used, dosage may be initiated with one tablet three or four times a day. However, this will not provide an adequate amount of carbidopa for many patients. Dosage may be increased by one tablet every day or every other day until a total of eight tablets (2 tablets q.i.d.) is reached.

Levodopa must be discontinued at least twelve hours before starting this combination product. A daily dosage of carbidopa and levodopa tablets USP should be chosen that will provide approximately 25% of the previous levodopa dosage. Patients who are taking less than 1500 mg of levodopa a day should be started on one carbidopa and levodopa tablet USP, 25 mg/100 mg three or four times a day. The suggested starting dosage for most patients taking more than 1500 mg of levodopa is one carbidopa and levodopa tablet USP, 25 mg/250 mg three or four times a day.

Therapy should be individualized and adjusted according to the desired therapeutic response. At least 70 to 100 mg of carbidopa per day should be provided. When a greater proportion of carbidopa is required, one carbidopa and levodopa tablet USP, 25 mg/100 mg may be substituted for each carbidopa and levodopa tablet USP, 10 mg/100 mg. When more levodopa is required, each carbidopa and levodopa tablet USP, 25 mg/250 mg should be substituted for a carbidopa and levodopa tablet USP, 25 mg/100 mg or a carbidopa and levodopa tablet USP, 10 mg/100 mg. If necessary, the dosage of carbidopa and levodopa tablets USP, 25 mg/250 mg may be increased by one-half or one tablet every day or every other day to a maximum of eight tablets a day. Experience with total daily dosages of carbidopa greater than 200 mg is limited.

Because both therapeutic and adverse responses occur more rapidly with this combination product than with levodopa alone, patients should be monitored closely during the dose adjustment period. Specifically, involuntary movements will occur more rapidly with carbidopa and levodopa than with levodopa. The occurrence of involuntary movements may require dosage reduction. Blepharospasm may be a useful early sign of excess dosage in some patients.

Standard drugs for Parkinson’s disease, other than levodopa without a decarboxylase inhibitor, may be used concomitantly while carbidopa and levodopa therapy is being administered, although dosage adjustments may be required.

Sporadic cases of hyperpyrexia and confusion have been associated with dose reductions and withdrawal of carbidopa and levodopa tablets USP. Patients should be observed carefully if abrupt reduction or discontinuation of carbidopa and levodopa tablets USP is required, especially if the patient is receiving neuroleptics (see WARNINGS).

If general anesthesia is required, carbidopa and levodopa therapy may be continued as long as the patient is permitted to take fluids and medication by mouth. If therapy is interrupted temporarily, the patient should be observed for symptoms resembling NMS, and the usual daily dosage may be administered as soon as the patient is able to take oral medication.

The optimum daily dosage of carbidopa and levodopa tablets must be determined by careful titration in each patient. Carbidopa and levodopa tablets are available in a 1:4 ratio of carbidopa to levodopa (carbidopa and levodopa tablets, USP 25 mg/100 mg) as well as 1:10 ratio (carbidopa and levodopa tablets, USP 25 mg/250 mg and carbidopa and levodopa tablets, USP 10 mg/100 mg). Tablets of the two ratios may be given separately or combined as needed to provide the optimum dosage.

Studies show that peripheral dopa decarboxylase is saturated by carbidopa at approximately 70 to 100 mg a day. Patients receiving less than this amount of carbidopa are more likely to experience nausea and vomiting.

Dosage is best initiated with one tablet of carbidopa and levodopa 25 mg/100 mg three times a day. This dosage schedule provides 75 mg of carbidopa per day. Dosage may be increased by one tablet every day or every other day, as necessary, until a dosage of eight tablets of carbidopa and levodopa 25 mg/100 mg a day is reached.

If carbidopa and levodopa tablets10 mg/100 mg is used, dosage may be initiated with one tablet three or four times a day. However, this will not provide an adequate amount of carbidopa for many patients. Dosage may be increased by one tablet every day or every other day until a total of eight tablets (2 tablets q.i.d.) is reached.

Levodopa must be discontinued at least twelve hours before starting carbidopa and levodopa tablets. A daily dosage of carbidopa and levodopa tablets should be chosen that will provide approximately 25% of the previous levodopa dosage. Patients who are taking less than 1500 mg of levodopa a day should be started on one tablet of carbidopa and levodopa 25 mg/100 mg three or four times a day. The suggested starting dosage for most patients taking more than 1500 mg of levodopa is one tablet of carbidopa and levodopa 25 mg/250 mg three or four times a day.

Therapy should be individualized and adjusted according to the desired therapeutic response. At least 70 to 100 mg of carbidopa per day should be provided. When a greater proportion of carbidopa is required, one tablet of carbidopa and levodopa 25 mg/100 mg may be substituted for each tablet of carbidopa and levodopa 10 mg/100 mg. When more levodopa is required, carbidopa and levodopa 25 mg/250 mg should be substituted for carbidopa and levodopa 25 mg/100 mg or carbidopa and levodopa 10 mg/100 mg. If necessary, the dosage of carbidopa and levodopa 25 mg/250 mg may be increased by one-half or one tablet every day or every other day to a maximum of eight tablets a day. Experience with total daily dosages of carbidopa greater than 200 mg is limited.

Because both therapeutic and adverse responses occur more rapidly with carbidopa and levodopa tablets than with levodopa alone, patients should be monitored closely during the dose adjustment period. Specifically, involuntary movements will occur more rapidly with carbidopa and levodopa tablets than with levodopa. The occurrence of involuntary movements may require dosage reduction. Blepharospasm may be a useful early sign of excess dosage in some patients.

Standard drugs for Parkinson's disease, other than levodopa without a decarboxylase inhibitor, may be used concomitantly while carbidopa and levodopa tablets are being administered, although dosage adjustments may be required.

Sporadic cases of hyperpyrexia and confusion have been associated with dose reductions and withdrawal of carbidopa and levodopa tablets. Patients should be observed carefully if abrupt reduction or discontinuation of carbidopa and levodopa tablets is required, especially if the patient is receiving neuroleptics. (See WARNINGS.)

If general anesthesia is required, carbidopa and levodopa tablets may be continued as long as the patient is permitted to take fluids and medication by mouth. If therapy is interrupted temporarily, the patient should be observed for symptoms resembling NMS, and the usual daily dosage may be administered as soon as the patient is able to take oral medication.

The optimum daily dosage of carbidopa and levodopa tablets USP must be determined by careful titration in each patient. Carbidopa and levodopa tablets USP are available in a 1:4 ratio of carbidopa to levodopa (25 mg/100 mg) as well as 1:10 ratio (25 mg/250 mg and 10 mg/100 mg). Tablets of the two ratios may be given separately or combined as needed to provide the optimum dosage.

Studies show that peripheral dopa decarboxylase is saturated by carbidopa at approximately 70 to 100 mg a day. Patients receiving less than this amount of carbidopa are more likely to experience nausea and vomiting.

Dosage is best initiated with one carbidopa and levodopa tablet USP, 25 mg/100 mg three times a day. This dosage schedule provides 75 mg of carbidopa per day. Dosage may be increased by one tablet every day or every other day, as necessary, until a dosage of eight carbidopa and levodopa tablets USP, 25 mg/100 mg a day is reached.

If carbidopa and levodopa tablets USP, 10 mg/100 mg are used, dosage may be initiated with one tablet three or four times a day. However, this will not provide an adequate amount of carbidopa for many patients. Dosage may be increased by one tablet every day or every other day until a total of eight tablets (2 tablets q.i.d.) is reached.

Levodopa must be discontinued at least twelve hours before starting this combination product. A daily dosage of carbidopa and levodopa tablets USP should be chosen that will provide approximately 25% of the previous levodopa dosage. Patients who are taking less than 1500 mg of levodopa a day should be started on one carbidopa and levodopa tablet USP, 25 mg/100 mg three or four times a day. The suggested starting dosage for most patients taking more than 1500 mg of levodopa is one carbidopa and levodopa tablet USP, 25 mg/250 mg three or four times a day.

Therapy should be individualized and adjusted according to the desired therapeutic response. At least 70 to 100 mg of carbidopa per day should be provided. When a greater proportion of carbidopa is required, one carbidopa and levodopa tablet USP, 25 mg/100 mg may be substituted for each carbidopa and levodopa tablet USP, 10 mg/100 mg. When more levodopa is required, each carbidopa and levodopa tablet USP, 25 mg/250 mg should be substituted for a carbidopa and levodopa tablet USP, 25 mg/100 mg or a carbidopa and levodopa tablet USP, 10 mg/100 mg. If necessary, the dosage of carbidopa and levodopa tablets USP, 25 mg/250 mg may be increased by one-half or one tablet every day or every other day to a maximum of eight tablets a day. Experience with total daily dosages of carbidopa greater than 200 mg is limited.

Because both therapeutic and adverse responses occur more rapidly with this combination product than with levodopa alone, patients should be monitored closely during the dose adjustment period. Specifically, involuntary movements will occur more rapidly with carbidopa and levodopa than with levodopa. The occurrence of involuntary movements may require dosage reduction. Blepharospasm may be a useful early sign of excess dosage in some patients.

Standard drugs for Parkinson’s disease, other than levodopa without a decarboxylase inhibitor, may be used concomitantly while carbidopa and levodopa therapy is being administered, although dosage adjustments may be required.

Sporadic cases of hyperpyrexia and confusion have been associated with dose reductions and withdrawal of carbidopa and levodopa tablets USP. Patients should be observed carefully if abrupt reduction or discontinuation of carbidopa and levodopa tablets USP is required, especially if the patient is receiving neuroleptics (see WARNINGS).

If general anesthesia is required, carbidopa and levodopa therapy may be continued as long as the patient is permitted to take fluids and medication by mouth. If therapy is interrupted temporarily, the patient should be observed for symptoms resembling NMS, and the usual daily dosage may be administered as soon as the patient is able to take oral medication.

Carbidopa and levodopa extended-release tablets contain carbidopa and levodopa in a 1:4 ratio as either the 50 mg/200 mg tablet or the 25 mg/100 mg tablet. The daily dosage of carbidopa and levodopa extended-release must be determined by careful titration. Patients should be monitored closely during the dose adjustment period, particularly with regard to appearance or worsening of involuntary movements, dyskinesias or nausea. Carbidopa and levodopa extended-release tablets should not be chewed or crushed.

Standard drugs for Parkinson's disease, other than levodopa without a decarboxylase inhibitor, may be used concomitantly while carbidopa and levodopa extended-release is being administered, although their dosage may have to be adjusted.

Since carbidopa prevents the reversal of levodopa effects caused by pyridoxine, carbidopa and levodopa extended-release can be given to patients receiving supplemental pyridoxine (vitamin B6).

Patients currently treated with conventional carbidopa levodopa preparations: Studies show that peripheral dopa-decarboxylase is saturated by the bioavailable carbidopa at doses of 70 mg a day and greater. Because the bioavailabilities of carbidopa and levodopa in carbidopa and levodopa and carbidopa and levodopa extended-release are different, appropriate adjustments should be made, as shown in Table 2.

Tablet

Amount of
Levodopa (mg)
in Each Tablet

Approximate
Bioavailability

Approximate Amount
of Bioavailable
Levodopa (mg) in
Each Tablet

Carbidopa and Levodopa Extended-release
50 mg/200 mg

200

0.70 to 0.75†

140 to 150

Carbidopa and Levodopa 25 mg/100 mg

100

0.99‡

99

Dosage with carbidopa and levodopa extended-release should be substituted at an amount that provides approximately 10% more levodopa per day, although this may need to be increased to a dosage that provides up to 30% more levodopa per day depending on clinical response (see DOSAGE AND ADMINISTRATION, Titration with carbidopa and levodopa extended-release). The interval between doses of carbidopa and levodopa extended-release should be 4 to 8 hours during the waking day. (See CLINICAL PHARMACOLOGY: Pharmacodynamics.)

A guideline for initiation of carbidopa and levodopa extended-release is shown in Table 3.

Carbidopa and Levodopa
Total Daily Dose*
Levodopa (mg)

Carbidopa and Levodopa Extended-Release
Suggested
Dosage Regimen

300 to 400

200 mg b.i.d.

500 to 600

300 mg b.i.d. or 200 mg t.i.d.

700 to 800

A total of 800 mg in 3 or more divided doses (e.g., 300 mg a.m., 300 mg early p.m., and 200 mg later p.m.)

900 to 1000

A total of 1000 mg in 3 or more divided doses (e.g., 400 mg a.m., 400 mg early p.m., and 200 mg later p.m.)

Patients currently treated with levodopa without a decarboxylase inhibitor: Levodopa must be discontinued at least twelve hours before therapy with carbidopa and levodopa extended-release is started. Carbidopa and levodopa extended-release should be substituted at a dosage that will provide approximately 25% of the previous levodopa dosage. In patients with mild to moderate disease, the initial dose is usually 1 tablet of 50 mg/200 mg carbidopa and levodopa extended-release tablets b.i.d.

Patients not receiving levodopa: In patients with mild to moderate disease, the initial recommended dose is 1 tablet of 50 mg/200 mg carbidopa and levodopa extended-release tablets b.i.d. Initial dosage should not be given at intervals of less than 6 hours.

Following initiation of therapy, doses and dosing intervals may be increased or decreased depending upon therapeutic response. Most patients have been adequately treated with doses of carbidopa and levodopa extended-release that provide 400 to 1600 mg of levodopa per day, administered as divided doses at intervals ranging from 4 to 8 hours during the waking day. Higher doses of carbidopa and levodopa extended-release (2400 mg or more of levodopa per day) and shorter intervals (less than 4 hours) have been used, but are not usually recommended.

When doses of carbidopa and levodopa extended-release are given at intervals of less than 4 hours, and/or if the divided doses are not equal, it is recommended that the smaller doses be given at the end of the day.

An interval of at least 3 days between dosage adjustments is recommended.

Because Parkinson's disease is progressive, periodic clinical evaluations are recommended; adjustment of the dosage regimen of carbidopa and levodopa extended-release may be required.

Anticholinergic agents, dopamine agonists, and amantadine can be given with carbidopa and levodopa extended-release. Dosage adjustment of carbidopa and levodopa extended-release may be necessary when these agents are added.

A dose of carbidopa and levodopa immediate release 25 mg/100 mg or 10 mg/100 mg (one half or a whole tablet) can be added to the dosage regimen of carbidopa and levodopa extended-release in selected patients with advanced disease who need additional immediate-release levodopa for a brief time during daytime hours.

Sporadic cases of hyperpyrexia and confusion have been associated with dose reductions and withdrawal of carbidopa and levodopa or carbidopa and levodopa extended-release.

Patients should be observed carefully if abrupt reduction or discontinuation of carbidopa and levodopa extended-release is required, especially if the patient is receiving neuroleptics. (See WARNINGS.)

If general anesthesia is required, carbidopa and levodopa extended-release may be continued as long as the patient is permitted to take oral medication. If therapy is interrupted temporarily, the patient should be observed for symptoms resembling NMS, and the usual dosage should be administered as soon as the patient is able to take oral medication.