Olanzapine versus haloperidol in the treatment of schizoaffective disorder. Acute and long-term therapy.

BACKGROUND: The effectiveness of antipsychotic monotherapy in schizoaffective disorder is limited, and further constrained by safety concerns.

AIMS: We aimed to compare the efficacy, tolerability and safety profile of the new pharmaceutical, olanzapine, with haloperidol.

METHOD: Data were assessed from 300 DSM-III-R schizoaffective subjects from a larger double-blind prospective international study. Subjects were randomly allocated to six weeks of olanzapine (5-20 mg) or haloperidol (5-20 mg) treatment; responders were followed for up to one year of double-blind, long-term maintenance therapy.

RESULTS: Olanzapine-treated patients achieved a statistically significant greater improvement than haloperidol treated patients on overall measures of efficacy, including clinical response. Significantly fewer olanzapine patients left the study early, and fewer adverse events were observed among those receiving olanzapine. During maintenance, olanzapine-treated patients continued to experience additional improvement, with fewer EPS but more weight gain than those on haloperidol.

CONCLUSIONS: Olanzapine demonstrated substantial advantages over the conventional antipsychotic haloperidol in the management of schizoaffective disorder.