The efficacy of a rapid-acting intramuscular formulation of olanzapine forpositive symptoms

Rapid tranquilization of acutely psychotic patients with schizophrenia is u sually carried out using typical antipsychotic agents. The objective of suc h treatment is to control agitation, not to treat psychosis, which usually responds only after a few weeks of treatment. An intramuscular formulation of the atypical antipsychotic olanzapine was developed for treatment of agi tation in acutely psychotic patients. Studies conducted to assess control o f agitation in schizophrenia also investigated the positive symptom efficac y of olanzapine when used to provide rapid tranquilization. This article su mmarizes the results of 3 clinical trials with intramuscular olanzapine wit h regard to positive symptom efficacy as measured by the Brief Psychiatric Rating Scale (BPRS; 0-6 scale) positive subscale. In 2 open-label trials, p atients treated with intramuscular olanzapine experienced a mean decrease f rom baseline in BPRS positive subscale score. In 1 double-blind clinical tr ial of intramuscular olanzapine versus intramuscular haloperidol and intram uscular placebo, the mean decrease from baseline in BPRS positive subscale score for patients treated with intramuscular olanzapine was statistically significant (p < .05). In all 3 studies, positive symptom improvement conti nued following transition to oral olanzapine. These results suggest that in tramuscular olanzapine has positive symptom efficacy early in the course of treatment and may provide a smooth transition to maintenance therapy with oral olanzapine.