Toshihiko Kinoshita

Aims A meta‐analysis of short‐term studies revealed no significant differences between the doses of asenapine, 10 and 20 mg/day, in the acute treatment of schizophrenia. However, it should be noted that many patients from clinical practice were excluded, and the dose–response to asenapine in a real‐world setting is still unclear. Additionally, the dose–response in the maintenance phase is not clear. This study aimed to evaluate the differences in the efficacy of different asenapine doses in patients with maintenance phase of schizophrenia in a real‐world setting. Methods This study conducted post‐marketing surveillance of asenapine in clinical settings in Japan. It followed patients diagnosed with schizophrenia who received asenapine for the first time for a maximum of 52 weeks. These patients were divided into two categories based on their average daily asenapine dosage: ≤10 mg/day and >10 mg/day. Asenapine efficacy was assessed by adjusting for patient demographics using multivariate logistic regression analysis, employing the Clinical Global Impression‐Global Improvement (CGI‐I) scale, which has seven categories. Results A total of 2774 patients were included in the analysis. Of these, 1689 and 1085 patients were treated with asenapine ≤10 mg/day and >10 mg/day, respectively. The CGI‐I improvement rate was significantly higher in the asenapine >10 group ( p = 0.012) after adjusting for patient background factors. Conclusion These results suggest that asenapine doses >10 mg/day may be more effective than 10 mg/day in the treatment of schizophrenia; however, further studies are needed to confirm these findings.