Seizure Incidence in Patients under Clozapine

Clozapine can cause potentially fatal side effects, including seizures. In the absence of therapeutic alternatives, well-coded guidelines are required for the management of this adverse effect in order to maintain treatment. Our aim is to determine the incidence of seizures associated with clozapine use in our hospital, to study the factors associated with this side effect, and to establish a clear, unified attitude based on a review of the literature. Among 483 patients treated with clozapine, 11 cases of seizures were reported, with a rate of 2.27% and an incidence of 1.62 cases per 1000 person-years. 80% of these patients presented tonic-clonic seizures, preceded by myoclonus in 2 cases, and the average seizure onset dose was estimated at 560mg/day. The course of action varied from one psychiatrist to another. Clozapine was discontinued in the case of one patient after the first episode, and doses were reduced in 8 patients from 28 to 75% of the therapeutic dose reached before. Six patients received additional antiepileptic agent.