Paliperidone palmitate vs. paliperidone extended-release for the acute treatment of adults with schizophrenia: a systematic review and pairwise and network meta-analysis

Is paliperidone palmitate (PP) a useful treatment option for adults with acute symptoms of schizophrenia? We conducted a systematic review and a random-effects pairwise and network meta-analysis that compared PP (25−150 mg equivalent) with paliperidone extended-release (PAL-ER, 3−12 mg/d) regarding their efficacy and safety in adults with acute symptoms of schizophrenia. The outcomes were the total score of the Positive and Negative Syndrome Scale (PANSS-T) at week 6 (the primary outcome for efficacy) and all-cause discontinuation(the primary outcome for acceptability), discontinuation due to inefficacy, discontinuation due to adverse events, discontinuation due to the withdrawal of consent, and the incidence of individual adverse events. Five studies on PP and seven studies on PAL-ER, which involved 4970 individuals in total, were included in this study. For the primary outcomes, we only included data from the treatment arms that used 100 or 150 mg equivalent as an initial dose of PP and data from the treatment arms that used 6, 9, or 12 mg as an initial dose of PAL-ER. The pairwise meta-analyses showed that both PP and PAL-ER outperformed placebo regarding PANSS-T at week 6 and all-cause discontinuation. However, there were no statistically significant differences in these outcomes between the effect sizes of PP and that of PAL-ER. Both PP and PAL-ER increased blood prolactin levels in both females and males compared with placebo. PAL-ER significantly increased blood prolactin in both females and males compared with PP. There were no statistically significant differences in other outcomes between the effect sizes of PP and that of PAL-ER. Similar results in all outcomes were observed in the network meta-analyses. In conclusion, PP might be a useful treatment option for adults with acute symptoms of schizophrenia. A noninferiority study that directly compares PP with PAL-ER for acute schizophrenia, conducted according to the recommended regimen, is required to provide solid evidence.