2.1 General Instruction for Use
The recommended dose for Desvenlafaxine Extended-Release Tablets is 50 mg once daily, with or without food.
In clinical studies, doses of 50 mg to 400 mg per day were shown to be effective, although no additional benefit was demonstrated at doses greater than 50 mg per day and adverse reactions and discontinuations were more frequent at higher doses.
When discontinuing therapy, gradual dose reduction is recommended whenever possible to minimize discontinuation symptoms [see Dosage and Administration (2.4 ) and Warnings and Precautions (5.7 )].
Desvenlafaxine Extended-Release Tablets should be taken at approximately the same time each day. Tablets must be swallowed whole with fluid and not divided, crushed, chewed, or dissolved.
2.2 Special Populations
Patients with renal impairment
The maximum recommended dose in patients with moderate renal impairment (24-hr creatinine clearance [CrCl] = 30 to 50 mL/min, Cockcroft-Gault [C-G]) is 50 mg per day. The maximum recommended dose in patients with severe renal impairment (24-hr CrCl less than 30 mL/min, C-G) or end-stage renal disease (ESRD) is 50 mg every other day. Supplemental doses should not be given to patients after dialysis [see Use in Specific Populations (8.6 ) and Clinical Pharmacology (12.3 .)].
Patients with hepatic impairment
The recommended dose in patients with moderate to severe hepatic impairment is 50 mg per day. Dose escalation above 100 mg per day is not recommended [see Clinical Pharmacology (12.3 )].
2.3 Maintenance/Continuation/Extended Treatment
It is generally agreed that acute episodes of major depressive disorder require several months or longer of sustained pharmacologic therapy. Patients should be periodically reassessed to determine the need for continued treatment.
2.4 Discontinuing Desvenlafaxine Extended-Release Tablets
Symptoms associated with discontinuation of Desvenlafaxine Extended-Release Tablets, other SNRIs and SSRIs have been reported [see Warnings and Precautions (5.7 )]. Patients should be monitored for these symptoms when discontinuing treatment. A gradual reduction in the dose rather than abrupt cessation is recommended whenever possible. If intolerable symptoms occur following a decrease in the dose or upon discontinuation of treatment, then resuming the previously prescribed dose may be considered. Subsequently, the physician may continue decreasing the dose, but at a more gradual rate.
2.5 Switching Patients From Other Antidepressants to Desvenlafaxine Extended-Release Tablets
Discontinuation symptoms have been reported when switching patients from other antidepressants, including venlafaxine, to desvenlafaxine. Tapering of the initial antidepressant may be necessary to minimize discontinuation symptoms.
2.6 Switching Patients To or From a Monoamine Oxidase Inhibitor (MAOI) Intended to Treat Psychiatric Disorders
At least 14 days should elapse between discontinuation of an MAOI intended to treat psychiatric disorders and initiation of therapy with Desvenlafaxine Extended-Release Tablets. Conversely, at least 7 days should be allowed after stopping Desvenlafaxine Extended-Release Tablets before starting an MAOI intended to treat psychiatric disorders [see Contraindications (4 )].
Use of Desvenlafaxine Extended-Release Tablets with other MAOIs such as Linezolid or Methylene Blue
Do not start Desvenlafaxine Extended-Release Tablets in a patient who is being treated with linezolid or intravenous methylene blue because there is increased risk of serotonin syndrome. In a patient who requires more urgent treatment of a psychiatric condition, other interventions, including hospitalization, should be considered [see Contraindications (4 )] .
In some cases, a patient already receiving Desvenlafaxine Extended-Release Tablets therapy may require urgent treatment with linezolid or intravenous methylene blue. If acceptable alternatives to linezolid or intravenous methylene blue treatment are not available and the potential benefits of linezolid or intravenous methylene blue treatment are judged to outweigh the risks of serotonin syndrome in a particular patient, Desvenlafaxine Extended-Release Tablets should be stopped promptly, and linezolid or intravenous methylene blue can be administered. The patient should be monitored for symptoms of serotonin syndrome for 7 days or until 24 hours after the last dose of linezolid or intravenous methylene blue, whichever comes first. Therapy with Desvenlafaxine Extended-Release Tablets may be resumed 24 hours after the last dose of linezolid or intravenous methylene blue [see Warnings and Precautions (5.2 )].
The risk of administering methylene blue by non-intravenous routes (such as oral tablets or by local injection) or in intravenous doses much lower than 1 mg/kg with Desvenlafaxine Extended-Release Tablets is unclear. The clinician should, nevertheless, be aware of the possibility of emergent symptoms of serotonin syndrome with such use [see Warnings and Precautions (5.2 )].