Dosage And Administration
PRISTIQ is not indicated for use in children under 18 years of age (see WARNINGS AND PRECAUTIONS, Potential Association with Behavioural and Emotional Changes, Including Self-Harm).
Recommended Dose and Dosage Adjustment
The recommended starting dose of PRISTIQ (desvenlafaxine succinate extended-release tablets) is 50 mg once daily, with or without food. In clinical studies, no additional benefit was demonstrated at doses greater than 50 mg/day. If the physician, based on clinical judgment, decides a dose increase above 50 mg/day is warranted for an individual patient, the maximum recommended dose should not exceed 100 mg/day. In clinical studies, doses of 50-400 mg/day were shown to be effective, although no additional benefit was demonstrated at doses greater than 50 mg/day, and adverse events and discontinuations were more frequent at higher doses. Patients should be periodically reassessed to determine the need for continued treatment.
It is generally agreed that acute episodes of major depression require several months or longer of sustained pharmacologic therapy beyond response to the acute episode. Long-term efficacy of PRISTIQ (50 daily) for up to 26 weeks, following response during 20 weeks of acute, open-label treatment, was established in a placebo-controlled trial. Patients should be periodically reassessed to determine the need for maintenance treatment.
It is recommended that PRISTIQ be taken at approximately the same time each day.
PRISTIQ tablets must be swallowed whole with liquids, and must not be chewed, divided or crushed. The medication is contained within a non-absorbable shell designed to release the drug at a controlled rate. The tablet shell, along with insoluble core components, is eliminated from the body; patients should not be concerned if they occasionally notice something that looks like a tablet in their stool. Due to the controlled-release design, PRISTIQ tablets should only be used in patients who are able to swallow the tablets whole.
A patient missing a dose should take it as soon as they remember to. If it is almost time for the next dose, the missed dose should be skipped. The patient should be cautioned against taking two doses concomitantly to “make up” for the missed dose.
Symptoms associated with discontinuation of PRISTIQ, other SNRIs and SSRIs have been reported (see WARNINGS AND PRECAUTIONS, Discontinuation Symptoms and ADVERSE REACTIONS, Discontinuation symptoms). Patients should be monitored for these symptoms when discontinuing treatment. A gradual reduction in the dose rather than abrupt cessation is recommended. 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. In some patients, discontinuation may need to occur over periods of months or longer.
Switching Patients from Other Antidepressants to PRISTIQ
Discontinuation symptoms have been reported when switching patients from other antidepressants, including venlafaxine, to PRISTIQ. Tapering of the initial antidepressant may be necessary to minimize discontinuation symptoms (see CONTRAINDICATIONS).
Switching Patients to or from a Monoamine Oxidase Inhibitor
At least 14 days should elapse between discontinuation of an MAOI and initiation of therapy with PRISTIQ. In addition, based on the half-life of desvenlafaxine succinate, at least 7 days should be allowed after stopping desvenlafaxine succinate before starting an MAOI.
Use of PRISTIQ with Reversible MAOIs such as Linezolid or Methylene Blue
Do not start PRISTIQ in a patient who is being treated with a reversible MAOI such as linezolid or in whom intravenous methylene blue has been administered because there is increased risk of serotonin syndrome (see CONTRAINDICATIONS). In a patient who requires more urgent treatment of a psychiatric condition, non-pharmacological interventions, including hospitalization, should be considered.
In some cases, a patient already receiving PRISTIQ 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 are judged to outweigh the risks of serotonin syndrome in a particular patient, PRISTIQ should be stopped promptly, and linezolid or intravenous methylene blue can be administered. The patient should be monitored for symptoms of serotonin syndrome for two weeks or until 24 hours after the last dose of linezolid or intravenous methylene blue, whichever comes first (see WARNINGS AND PRECAUTIONS). Therapy with PRISTIQ may be resumed 24 hours after the last dose of linezolid or intravenous methylene blue.
Patients with severe renal impairment and end-stage renal disease
The recommended dose in patients with severe renal impairment (24-hr CrCl < 30 mL/min) or end-stage renal disease (ESRD) is 50 mg every other day. Because of individual variability in clearance in these patients, individualization of dosage may be desirable. Supplemental doses should not be given to patients after dialysis (see ACTION AND CLINICAL PHARMACOLOGY, Renal Insufficiency).
Use in patients with hepatic impairment
No dosage adjustment is necessary for patients with hepatic impairment (see ACTION AND CLINICAL PHARMACOLOGY, Hepatic Insufficiency).
Geriatrics (≥ 65 years of age)
No dosage adjustment is required solely on the basis of age; however, possible reduced clearance of PRISTIQ should be considered when determining dose (see ACTION AND CLINICAL PHARMACOLOGY, Geriatrics).
PRISTIQ is not indicated for use in children under the age of 18. Two placebo controlled studies in 587 pediatric patients 7 to 17 years of age with MDD failed to demonstrate efficacy; neither short term, placebo-controlled study demonstrated statistically or clinically significant differences between PRISTIQ and placebo (see WARNINGS AND PRECAUTIONS, Potential Association with Behavioural and Emotional Changes, Including Self-Harm; ACTION AND CLINICAL PHARMACOLOGY, Pediatrics).
Discontinuation of Therapy
A gradual reduction in the dose rather than abrupt cessation is recommended whenever possible. Discontinuation regimens should take into account the individual circumstances of the patient, such as duration of treatment and dose at discontinuation (see WARNINGS AND PRECAUTIONS and ADVERSE REACTIONS).