Convulsive seizures in schizophrenic patients induced by zotepine administration.

One hundred twenty-nine schizophrenic inpatients who were administered zotepine were studied to see if they had zotepine-induced convulsive seizures. Twenty-two patients had grand mal seizures during the administration periods. The incidence of the seizure was 17.1% and was higher than that in previous reports. The average duration of zotepine administration before the seizure was 48.3 days. The incidence of the seizure was closely related to the daily dosage of zotepine, but there was no significant correlation between the daily dosage of zotepine and the duration of administration before the onset of the seizure. The patients who received a combined administration with the higher dose of zotepine and other phenothiazines were revealed to be more likely to have the seizure. In addition, young patients and patients with a past history of head injuries showed a high incidence of the seizure with the administration of zotepine.