Antipsychotic prescription patterns in outpatient settings: 24-month results from the Intercontinental Schizophrenia Outpatient Health Outcomes (IC-SOHO) study

Abstract

This report describes antipsychotic prescription patterns for outpatients with schizophrenia prescribed olanzapine (n=3222), clozapine (n=236), risperidone (n=1117), quetiapine (n=189) or haloperidol (n=256) monotherapy at study entry and treated in a naturalistic, clinical practice setting over 24 months. Predictive factors associated with remaining on monotherapy were also identified. Olanzapine patients had significantly greater odds of remaining on their initial monotherapy compared to other treatment groups, while clozapine or risperidone recipients were more likely to remain on monotherapy, compared to haloperidol patients. Switching antipsychotic medication was more common than addition of another antipsychotic agent, and the most common reason for modifying treatment was lack of effectiveness. The odds of modifying antipsychotic prescription due to intolerability were lower for patients treated with olanzapine, compared to patients treated with risperidone or haloperidol (p≤.001). However, treatment modification due to patient request was significantly greater for olanzapine-treated patients, compared to risperidone-, quetiapine- or haloperidol-treated patients (p≤.001).