Effectiveness and Safety of Switching from Oral Antipsychotics to Once-Monthly Paliperidone Palmitate (PP1M) in the Management of Schizophrenia: A Systematic Review and Meta-Analysis

BACKGROUND: Considering the improvement in adherence and convenience, once-monthly paliperidone palmitate (PP1M) has been increasingly used in the treatment of schizophrenia. However, the outcomes for patients who switch from oral antipsychotics (OAPs) to PP1M have not been reliably assessed. The objective of this systematic review and meta-analysis was to investigate the efficacy and safety of PP1M in the management of patients with schizophrenia with a prior history of OAP use. METHODS: We conducted a systematic search in PubMed, EMBASE, and the Cochrane Library on 19 July 2022 to identify eligible studies. All studies that examined the effectiveness and safety of switching from OAPs to PP1M in patients with schizophrenia were included. The primary outcomes were relapse rate, hospitalisation rate, and the change from baseline in the Positive and Negative Syndrome Scale (PANSS) total score. The secondary outcomes included the changed number of inpatient visits, changed length of stay hospitalisation, change from baseline in the Clinical Global Impressions-Severity (CGI-S) score and the personal and social performance (PSP) total score, response rate, proportion of treatment discontinuation, and adverse events. We included randomised-controlled trials (RCTs), single-arm studies, and observational studies. Case reports, case series, and reviews were excluded. The quality assessment of included studies was performed using the Revised Cochrane risk-of-bias tool for randomised trials (RoB2), the 9-point Newcastle-Ottawa Scale (NOS) instrument for non-randomised studies and cohort studies, and the 12-item National Institutes of Health (NIH) quality assessment tool for before-after (Pre-Post) study without control group. Follow-up times were reported as short- (≤ 13 weeks), medium- (14–26 weeks), and long term (≥ 27 weeks). Data were pooled using meta-analysis. RESULTS: Fifteen studies with a total of 4740 patients were included. The long-term relapse rates and hospitalisation rates were 12% (95% CI 0.07–0.18) and 18% (95% CI 0.15–0.20), respectively. The short-, medium-, and long-term change in PANSS total score was − 21.69 (95% CI − 30.02 to −13.36), − 14.98 (95% CI − 21.45 to − 8.51) and − 17.88 (95% CI − 31.94 to −3.82), respectively. Approximately 50% of patients reported at least a 30% reduction in the PANSS score at the short-term follow-up. Improvements in CGI-S and PSP score were observed during various periods. There was a reduction in the length of stay hospitalisation and the number of inpatient visits at the medium- and long-term follow-ups. Low discontinuation and adverse event rates were reported. CONCLUSION: Based on our findings, this study may support the efficacy and safety of switching from OAPs to PP1M for the treatment of patients with schizophrenia. Future large-scale studies are warranted to confirm our findings. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40263-023-01028-1.