Venlafaxinedosage

Venlafaxine extended-release tablets should be administered in a single dose with food either in the morning or in the evening at approximately the same time each day. Each tablet should be swallowed whole with fluid and not divided, crushed, chewed, or placed in water. Initial Treatment Indication Starting Dose Dose Increase Maximum Dose Major Depressive Disorder 75 mg/day (in some patients, 37.5 mg/day for 4-7 days) 75 mg/day increments at intervals of 4 days or longer 225 mg/day Social Anxiety Disorder 75 mg/day No benefit at higher doses 75 mg/day Venlafaxine extended-release tablets should be taken as a single daily dose with food in either the morning or evening at the same time each day.

Discontinuation: Gradual; individualized as necessary.

2.1 Initial

Treatment Major Depressive Disorder For most patients, the recommended starting dose for venlafaxine extended-release tablets is 75 mg/day, administered in a single dose. In the clinical trials establishing the efficacy of venlafaxine hydrochloride extended-release capsules in moderately depressed outpatients, the initial dose of venlafaxine was 75 mg/day. For some patients, it may be desirable to start at 37.5 mg/day for 4 to 7 days to allow new patients to adjust to the medication before increasing to 75 mg/day. While the relationship between dose and antidepressant response for venlafaxine hydrochloride extended-release capsules has not been adequately explored, patients not responding to the initial 75 mg/day dose may benefit from dose increases to a maximum of approximately 225 mg/day. Dose increases should be in increments of up to 75 mg/day, as needed, and should be made at intervals of not less than 4 days, since steady state plasma levels of venlafaxine and its major metabolites are achieved in most patients by day 4. In the clinical trials establishing efficacy, upward titration was permitted at intervals of 2 weeks or more; the average doses were about 140 to 180 mg/day. It should be noted that, while the maximum recommended dose for moderately depressed outpatients is also 225 mg/day for venlafaxine hydrochloride immediate-release tablets, more severely depressed inpatients in one study of the development program for that product responded to a mean dose of 350 mg/day (range of 150 to 375 mg/day). Whether or not higher doses of venlafaxine extended-release tablets are needed for more severely depressed patients is unknown; however, the experience with venlafaxine hydrochloride extended-release capsule doses higher than 225 mg/day is very limited. Social Anxiety Disorder (Social Phobia) The recommended dose is 75 mg/day, administered in a single dose. There was no evidence that higher doses confer any additional benefit.

2.2 Maintenance

Treatment There is no body of evidence available from controlled trials to indicate how long patients with major depressive disorder should be treated with venlafaxine extended-release tablets. It is generally agreed that acute episodes of major depressive disorder require several months or longer of sustained pharmacological therapy beyond response to the acute episode. In one study, in which patients responding during 8 weeks of acute treatment with venlafaxine hydrochloride extended-release capsules were assigned randomly to placebo or to the same dose of venlafaxine hydrochloride extended-release capsules (75, 150, or 225 mg per day, qAM) during 26 weeks of maintenance treatment as they had received during the acute stabilization phase, longer-term efficacy was demonstrated. A second longer-term study has demonstrated the efficacy of venlafaxine hydrochloride immediate-release tablets in maintaining a response in patients with recurrent major depressive disorder who had responded and continued to be improved during an initial 26 weeks of treatment and were then randomly assigned to placebo or venlafaxine hydrochloride immediate-release tablets for periods of up to 52 weeks on the same dose (100 to 200 mg/day, on a b.i.d. schedule). Based on these limited data, it is not known whether or not the dose of venlafaxine extended-release tablets needed for maintenance treatment is identical to the dose needed to achieve an initial response. Patients should be periodically reassessed to determine the need for maintenance treatment and the appropriate dose for such treatment.

2.3 Special

Populations Treatment of Pregnant Women During the Third Trimester Neonates exposed to venlafaxine hydrochloride extended-release capsules, other SNRIs, or SSRIs, late in the third trimester have developed complications requiring prolonged hospitalization, respiratory support, and tube feeding. When treating pregnant women with venlafaxine extended-release tablets during the third trimester, the physician should carefully consider the potential risks and benefits of treatment. Patients with Hepatic Impairment Given the decrease in clearance and increase in elimination half-life for both venlafaxine and ODV that is observed in patients with hepatic cirrhosis and mild and moderate hepatic impairment compared with normal subjects, it is recommended that the total daily dose be reduced by 50% in patients with mild to moderate hepatic impairment. Since there was much individual variability in clearance between patients with cirrhosis, it may be necessary to reduce the dose even more than 50%, and individualization of dosing may be desirable in some patients. Patients with Renal Impairment Given the decrease in clearance for venlafaxine and the increase in elimination half-life for both venlafaxine and ODV that is observed in patients with renal impairment (GFR = 10 to 70 mL/min) compared with normal subjects, it is recommended that the total daily dose be reduced by 25% to 50%. In patients undergoing hemodialysis, it is recommended that the total daily dose be reduced by 50%. Because there was much individual variability in clearance between patients with renal impairment, individualization of dosage may be desirable in some patients. Elderly Patients No dose adjustment is recommended for elderly patients solely on the basis of age. As with any drug for the treatment of major depressive disorder or Social Anxiety Disorder, however, caution should be exercised in treating the elderly. When individualizing the dosage, extra care should be taken when increasing the dose.

2.4 Discontinuing

Venlafaxine Extended-Release Tablets Symptoms associated with discontinuation of venlafaxine hydrochloride extended-release capsules, other SNRI's, and SSRI's have been reported. 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. In clinical trials with venlafaxine hydrochloride extended-release capsules, tapering was achieved by reducing the daily dose by 75 mg at 1 week intervals. Individualization of tapering may be necessary.

2.5 Switching

Patients from Venlafaxine Hydrochloride Immediate-Release Tablets Depressed patients who are currently being treated at a therapeutic dose with venlafaxine hydrochloride immediate-release tablets may be switched to venlafaxine extended-release tablets at the nearest equivalent dose (mg/day), e.g., 37.5 mg venlafaxine two-times-a-day to 75 mg venlafaxine extended-release tablets once daily. However, individual dosage adjustments may be necessary.

2.6 Switching a

Patient 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 venlafaxine extended-release tablets. Conversely, at least 7 days should be allowed after stopping venlafaxine extended-release tablets before starting an MAOI intended to treat psychiatric disorders.

2.7 Use of Venlafaxine

Extended-Release Tablets with Other MAOIs, Such as Linezolid or Methylene Blue Do not start venlafaxine 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. In some cases, a patient already receiving venlafaxine 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, venlafaxine 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 venlafaxine extended-release tablets may be resumed 24 hours after the last dose of linezolid or intravenous methylene blue. 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 venlafaxine extended-release tablets is unclear. The clinician should, nevertheless, be aware of the possibility of emergent symptoms of serotonin syndrome with such use.