Dosage must be adjusted according to each patient’s needs. Therapy for either hypertension or angina should be initiated with 30 or 60 mg once daily. Nifedipine Extended-Release Tablets USP should be swallowed whole and should not be bitten or divided. In general, titration should proceed over a 7 to 14 day period so that the physician can fully assess the response to each dose level and monitor blood pressure before proceeding to higher doses. Since steady-state plasma levels are achieved on the second day of dosing, titration may proceed more rapidly, if symptoms so warrant, provided the patient is assessed frequently. Titration to doses above 120 mg are not recommended.
Angina patients controlled on nifedipine capsules alone or in combination with other antianginal medications may be safely switched to nifedipine extended-release tablets at the nearest equivalent total daily dose (e.g., 30 mg t.i.d. of nifedipine capsules may be changed to 90 mg once daily of nifedipine extended-release tablets). Subsequent titration to higher or lower doses may be necessary and should be initiated as clinically warranted. Experience with doses greater than 90 mg in patients with angina is limited. Therefore, doses greater than 90 mg should be used with caution and only when clinically warranted.
Avoid coadministration of nifedipine with grapefruit juice (see CLINICAL PHARMACOLOGY and PRECAUTIONS: Other Interactions).
No “rebound effect” has been observed upon discontinuation of nifedipine extended-release tablets. However, if discontinuation of nifedipine is necessary, sound clinical practice suggests that the dosage should be decreased gradually with close physician supervision.
Care should be taken when dispensing nifedipine extended-release tablets to assure that the extended release dosage form has been prescribed.
Coadministration with Other Antianginal Drugs
Sublingual nitroglycerin may be taken as required for the control of acute manifestations of angina, particularly during nifedipine titration. See PRECAUTIONS, Drug Interactions, for information on coadministration of nifedipine with beta blockers or long-acting nitrates.
