Improved outcomes following a switch to olanzapine treatment from risperidone treatment in a 1-year naturalistic study of schizophrenia patients in Japan.

Aims: This study assessed clinical and functional outcomes following a switch from risperidone to olanzapine in a 1-year naturalistic study of schizophrenia patients in Japan. Methods: We used data from a large 1-year prospective, multicenter, observational non-interventional study of individuals who were initiated on olanzapine for the treatment of schizophrenia in Japan. Current analyses focused on patients who were switched at study entry from risperidone to olanzapine (n = 258). Repeated measures analysis was employed to assess outcomes on validated measures. Results: At study entry, 45% were inpatients and 55% outpatients. Participants were in their early 40s with mean illness duration of 14 years. Approximately half were male. Most were switched from risperidone to olanzapine due to poor medication efficacy (67.8%) rather than medication intolerability (29.1%). Most patients (67.8%) completed the 1-year study. Patients experienced clinically and statistically significant (P < 0.05) improvements in global symptom severity, positive, negative, depressive, and cognitive symptoms, health-related quality of life, and paid work rates. Most patients (59.2%) demonstrated treatment response to olanzapine and 43.4% experienced symptom remission. Mean weight gain was 2.19 kg, with one-third of patients (33.3%) experiencing clinically significant weight gain (=7%). Conclusions: In this 1-year naturalistic study, inpatients and outpatients who were switched from risperidone to olanzapine experienced clinically and statistically significant improvements in their clinical and functional outcomes. One-third of all patients experienced clinically significant weight gain. Current findings highlight the favorable benefit-to-risk profile of switching to olanzapine therapy following treatment failure on risperidone among patients with schizophrenia in Japan.