Olanzapine in the treatment of delirium.

Delirium is an organic psychiatric syndrome characterized by fluctuating consciousness and impaired cognitive functioning. Eleven delirious patients were treated with olanzapine (dosage mean +/- standard deviation [SD]: 8.2 +/- 3.4 mg qhs), and 11 delirious control patients were treated with haloperidol (dosage mean +/- SD: 5.1 +/- 3.5 mg qhs). Peak response time was similar in both groups. Five of the 11 olanzapine patients showed significant improvement (> 50% score reduction) on the Delirium Rating Scale (DRS) and no patients had side effects, whereas 6 of the 11 control subjects showed improvement on the DRS and 5 had extrapyramidal symptoms or excessive sedation. Olanzapine may be a useful alternative to haloperidol in the treatment of delirium in hospitalized patients.