Antimanic effect of zotepine.

The antimanic effect of zotepine was investigated in 16 patients with manic-depressive psychosis or manic schizoaffective psychosis. Zotepine markedly improved manic symptoms in 75% and afforded at least slight improvement in all patients studied. However, in 50%, zotepine caused conversion from mania to depression. The most frequent side effects were dysarthria in 50%, parkinsonian symptoms in 33%, dry mouth in 28%, and sleepiness in 28%. EEG abnormalities were noted in 22% of patients. The antimanic effect of zotepine was enhanced by lithium carbonate; however, concomitant use of zotepine and lithium possibly increased the incidence of EEG abnormalities. The conversion-to-depression effect of zotepine was not inhibited by lithium. Overall, the concomitant use of zotepine and lithium may be important in the treatment of manic psychoses.