High-dose olanzapine orally disintegrating tablets for treatment-resistant psychosis.

Sir: Olanzapine is a thienobenzodiazepine antipsychotic that has a broad in vitro affinity for several receptors, including serotonergic, cholinergic, dopaminergic, and adrenergic receptors. Olanzapine is approved for treatment of psychoses at doses up to 20 mg/day. New research suggests benefits of higher doses of olanzapine. Anecdotal case reports highlight the benefits of olanzapine at 50 mg/day in patients with refractory schizoaffective disorders. In the United Kingdom, a trial of high-dose olanzapine (range, 20– 60 mg/day) showed moderate to marked clinical improvement in patients with clozapine-resistant schizophrenia. Treatment-resistant psychosis is generally treated with clozapine, which requires frequent blood tests and is associated with several side effects, including weight gain, sedation, and agranulocytosis. Regular blood draws and the myriad of side effects often contribute to poor compliance with clozapine. However, when patients fail clozapine, few other options exist. We describe a patient who, after failing clozapine treatment, responded to the orally disintegrating formulation of high-dose olanzapine.