Optimal dose for the efficacy of asenapine in patients with schizophrenia: Real-world data

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.