Differences in Baseline Characteristics of Patients Treated with Olanzapine or Other Antipsychotics in Japanese Patients with Acute Schizophrenia: A 1-Year Observational Study under Routine Clinical Practice in Japan

Objective: Baseline characteristics of acute schizophrenia patients were analyzed to identify differences in the baseline characteristics of patients treated with olanzapine monotherapy compared with those treated with other antipsychotic monotherapies. Methods: This prospective, naturalistic observational study was designed to evaluate discontinuation rates of olanzapine and non-olanzapine antipsychotic monotherapy in Japanese adult patients with acute schizophrenia. Results: A total of 1089 patients were assessed: 578 patients were treated with olanzapine, 487 with non-olanzapine atypical antipsychotics, and 24 with typical antipsychotics. The mean Clinical Global Impression-Severity (CGI-S) Schizophrenia, Brief Psychiatric Rating Scale (BPRS) total, and BPRS positive scores were higher in patients treated with olanzapine compared with most of the non-olanzapine treated patients. The majority of patients with a CGI-S Schizophrenia score of 7 (29/41 patients) as well as patients with a BPRS total score of 90 or higher (14/18 patients) were treated with olanzapine. On the other hand, physicians tended to prescribe antipsychotics other than olanzapine for patients with heavier body weight or diabetes mellitus. Conclusion: The present study demonstrated that olanzapine was more likely to be prescribed to patients with more severe schizophrenia symptoms. However, further studies are warranted to reach a definite conclusion.