Effectivity of zotepine in refractory psychoses: possible relationship between zotepine and non-dopamine psychosis.

We reported the results of a survey of patients who suffered from schizophrenia with predominate hallucinatory and delusional states, and who had been unresponsive to a variety of antipsychotics like haloperidol but responded more favorably to zotepine. In 10 of the 22 zotepine-responsive patients in this study, there was marked improvement with zotepine. Considering the results from previous drug treatment, the phenothiazines (especially levomepromazine) surpassed the butyrophenones in efficacy, suggesting that zotepine might resemble levomepromazine clinically. After administration of zotepine, cenesthesic hallucination, behavior caused by hallucination, egorrhoe, affective symptoms, and catatonic symptoms were markedly improved. However, insight into disease and negative symptoms were minimally improved after administration of zotepine. Zotepine was effective in the refractory psychoses due to its potent action on the delusional dynamics, in spite of producing little marked improvement in such main symptoms as hallucination and delusion. The authors speculate that zotepine's potent activity at serotonin-1 receptors may lead to a beneficial effect in refractory psychoses, just as in the case of its antimanic effect.