Long-Term Improvement in Efficacy and Safety After Switching to Ziprasidone in Stable Outpatients with Schizophrenia

Introduction: The long-term efficacy and tolerability of treatment with ziprasidone following a switch from prior antipsychotics was evaluated in outpatients with schizophrenia or schizoaffective disorder in three open-label, flexible-dose, 1-year extension studies. Methods: These studies enrolled completers of 6-week trials in which subjects were switched to ziprasidone from conventional antipsychotics, olanzapine, or risperidone. Identical study designs and the small number of patients entering the extensions supported pooling of the data. Results: Of 185 pooled subjects entering the extension studies, 72 completed 58 weeks of treatment. Median treatment duration was 34.6 weeks; median dose was 120 mg/day at endpoint. The intent-to-treat population showed significant improvement in Positive and Negative Syndrome Scale (PANSS) total scores (-4.3 [P <=.01]), PANSS negative scores (-2.4 [P <=.0001]), and Clinical Global Impression of severity score (-0.3 [P <=.001]). Completers showed significant improvement in mean PANSS total scores (-10.2 [P <.0001]), PANSS positive scores (-2.7 [P <.0001]), PANSS negative scores (-2.7 [P <.001]), and Clinical Global Impression of severity scores (-0.6 [P <.0001]). Conclusion: Ziprasidone was well tolerated, and patients demonstrated significant improvement in metabolic parameters and in all movement disorder assessments. Insomnia and somnolence were the only adverse events with an incidence > 10% in pooled subjects. No subject had a corrected QT interval >= 500 msec.