FDA approves combination therapy for acute bipolar mania

[Andi]

Aug 6, 2003 The US Food and Drug Administration approved the use of olanzapine (Zyprexa) in combination with lithium or valproate (Depakote) to treat acute manic episodes of bipolar I disorder.

Olanzapine is an antipsychotic drug indicated for short-term treatment of acute manic episodes in bipolar I patients, either alone or in combination with lithium or valproate. It is also indicated for long-term therapy and maintenance of treatment response of schizophrenia.

Two 6-week, double-blind, randomized, placebo-controlled trials of 344 patients indicated that olanzapine in combination therapy was more effective in treating manic and depressive symptoms during a manic or mixed episode compared with lithium or valproate alone. Patients with inadequately controlled manic or mixed symptoms on lithium (therapeutic range of 0.6 milliequivalents/liter [mEq/L] to 1.2 mEq/L) or valproate (therapeutic range of 50 micrograms/milliliter [mcg/mL] to 125 mcg/mL) received either placebo or olanzapine (5-20 milligrams [mg] a day, starting at 10 mg/day).

Olanzapine dosing should be initiated at 10 mg a day without regard to meals; dosage adjustment of lithium or valproate is not necessary when used in combination with olanzapine.

To reduce the risk of neuroleptic malignant syndrome (potentially fatal), tardive dyskinesia (possibly irreversible), seizures, and orthostatic hypotension, olanzapine should be prescribed cautiously. As the duration of treatment and the total cumulative dose of antipsychotic drugs increase so does the risk of developing tardive dyskinesia. The incidence of orthostatic hypotension is higher during the initial dose-titration period and may be minimized by initiating therapy at 5 mg a day.

The most common adverse effect of olanzapine in combination therapy is dry mouth. Other adverse events are weight gain, increased appetite, dizziness, back pain, constipation, speech disorder, increased salivation, amnesia, and paresthesia.

The FDA is currently reviewing olanzapine for the use of long-term treatment of bipolar disorder and a olanzapine fluoxetine combination (Symbyax) for the treatment of bipolar depression.

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