The importance of dose in isocarboxazid therapy.

Little information is available on the effectiveness and safety of particular doses of isocarboxazid. In a study using isocarboxazid doses of 30 and 50 mg/day in depressed inpatients, the higher dose was well tolerated and did not result in any greater toxicity than the 30 mg dose. Significantly greater elevation of plasma serotonin (Week 2) and platelet MAO inhibition were seen with 50 mg/day. In nonmelancholic depressions, 50 mg proved to be more effective than 30 mg in symptoms of depression and anxiety. However, this did not apply to the vegetative-physiologic symptoms of depression.