To report a case of status epilepticus in a patient receiving olanzapine, with no previous history of seizure and no confirmed underlying cause for seizure.

A 48-year-old woman with low weight and psychotic disorder not otherwise specified, was admitted because of provoked vomiting and anorexia. She developed generalized tonic-clonic seizures that progressed to status epilepticus during her hospitalization. Two days earlier, treatment switched from mirtazapine 30 mg plus quetiapine to mirtazapine 30 mg plus olanzapine - with quick titration up to 30mg. No other toxic, metabolic, electrolyte or anatomic abnormality was identified. Olanzapine was discontinued and the patient was started on intravenous phenytoin, which was discontinued without complications one month later. The patient remained seizure free.

To our knowledge this is the second case of status epilepticus described that has been associated with the use of olanzapine, in a patient with no other confirmed predisposing factors for seizure. Olanzapine is an atypical antipsychotic that shares many pharmacological properties with clozapine. However, clozapine has been noted to induce dose-dependent seizures in about 10% of patients, whereas manufacturer's trials gave a seizure rate of 0,88% for olanzapine, similar to other antipsychotics. In our patient it is possible that seizures were induced due to the abrupt change in pharmacotherapy and the quick titration to high dose.

Although olanzapine has infrequently been associated with epileptogenic risk, it should be used cautiously especially when other predisposing factors exist.