458. EFFECTIVENESS OF LONG-ACTING INJECTABLE PALIPERIDONE PALMITATE ON RELAPSE PREVENTION OF SCHIZOPHRENIA

Abstract Background Long-acting injectable (LAI) antipsychotics have been widely used in treating people with schizophrenia. Aims & Objectives This study aimed to explore and compare the effectiveness of paliperidone palmitate once monthly (PP1M) and paliperidone palmitate 3-monthly (PP3M) in relapse prevention of schizophrenia in the real-world clinical practice. Method This was a cohort study conducted from 2014 to 2024 in a university hospital of Taiwan. Patients were categorized into 3 groups according to their naturalistic treatment: oral antipsychotics (OA) group, PP1M group, and PP3M group. Age, sex, previous hospitalization history, and previous psychiatric emergency history were collected. Patients were followed up to the end of the study or the event of relapse indicated by re-hospitalization or emergency. Kaplan-Meier survival analysis and Cox proportional hazard modeling were applied to analyze the outcomes. Results In Table 1, OA group had less previous admission and emergency than other groups, and less relapse according to Kaplan-Meier statistics. In Figure 1, PP3M group showed non-inferiority with OA group (HR 1.2, 95%CI 0.6 to 2.3, p=0.579), while PP1M group had higher risk of re-hospitalization (HR 2.1, 95%CI 1.4 to 3.2, p<0.001). Discussion & Conclusions Longer half-life of LAI antipsychotics may be more effective in relapse prevention of schizophrenia.