New-Onset Seizure Associated with Quetiapine and Olanzapine

Abstract
OBJECTIVE: To report a case involving a witnessed seizure in a patient receiving concurrent olanzapine and quetiapine. CASE SUMMARY: A 27-year-old white woman was observed to have a seizure while receiving a stable dosage of olanzapine 15 mg/d, with the addition of quetiapine 100 mg in the evening 1 day before the occurrence of the seizure. There were no known risk factors for epilepsy. DISCUSSION: This case reports a new-onset seizure in the context of concurrent olanzapine and quetiapine use. Interpretation is complicated by recent discontinuation of low-dose clonazepam. CONCLUSIONS: While uncommon, seizures can occur with non-clozapine atypical antipsychotics. Caution is indicated when using these drugs with other agents that may lower the seizure threshold.