Objective: The relative effectiveness of newly started antipsychotic drugs for individuals with schizophrenia may depend on multiple factors, including each patient's previous treatment response and the reason for a new medication trial. This randomized, double-blind study compared olanzapine, quetiapine, and risperidone in patients who had just discontinued the older antipsychotic perphenazine.
Method: Subjects with schizophrenia (N=114) who had been randomly assigned to and then discontinued perphenazine in phase 1 of the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) schizophrenia study were reassigned randomly to double-blinded treatment with olanzapine, 7.5-30.0 mg/day (N=38); quetiapine, 200-800 mg/day (N=38); or risperidone, 1.5-6.0 mg/day (N=38). The primary aim was to determine whether there were differences among these three treatments in effectiveness, as measured by time to treatment discontinuation for any reason. Secondary outcomes included reasons for treatment discontinuation and measures of drug tolerability.
Results: The time to treatment discontinuation was longer for patients treated with quetiapine (median, 9.9 months) and olanzapine (7.1 months) than with risperidone (3.6 months). There were no significant differences between treatments on discontinuation due to inefficacy, intolerability, or patient decision.
Conclusions: Among this group of patients with chronic schizophrenia who had just discontinued the older antipsychotic perphenazine, quetiapine and olanzapine were more effective than risperidone, as reflected by longer time to discontinuation for any reason. In the context of other results from the CATIE study, the effectiveness and acceptability of antipsychotic drugs appears to vary considerably according to clinical circumstances.