Kazuto Oya, Taro Kishi, Nakao Iwata

We conducted a systematic review and meta-analysis of the efficacy of aripiprazole once monthly (AOM) for schizophrenia. Randomized controlled trials (RCTs) on AOM, published until June 25, 2015, were retrieved from PubMed, Cochrane, and PsycINFO databases. Relative risk (RR), standardized mean difference (SMD), 95% confidence intervals (95% CIs), and numbers needed to treat/harm (NNT/NNH) were calculated. We identified four relevant RCTs (total n=1,860), two placebo-controlled trials, one noninferiority trial comparing AOM to oral aripiprazole (OA), and one including therapeutic doses of AOM and OA, as well as an AOM dose below therapeutic threshold (control arm). AOM was superior to placebo for decreasing Positive and Negative Syndrome Scale (PANSS) total scores (SMD =-0.65, 95% CI =-0.90 to -0.41, n=1,126). However, PANSS total scores did not differ significantly between pooled AOM and OA groups. The pooled AOM group showed significantly lower incidence of all-cause discontinuation (RR =0.54, 95% CI =0.41-0.71, n=1,139, NNH =4) and inefficacy (RR =0.28, 95% CI =0.21-0.38, n=1,139, NNH =5) than placebo, but was not superior to placebo regarding discontinuation due to adverse events (AEs) or death. The AOM group exhibited a lower incidence of all-cause discontinuation than OA (RR =0.78, 95% CI =0.64-0.95, n=986, NNH =14), but there were no intergroup differences in discontinuation due to inefficacy, AEs, or death. There were no significant differences in extrapyramidal symptoms scale scores between AOM and placebo or between AOM and OA. AOM resulted in higher weight gain than placebo (SMD =0.41, 95% CI =0.18-0.64, n=734) but lower than OA (SMD =-0.16, 95% CI =-0.29 to -0.02, n=847). AOM has antipsychotic efficacy and low risk of discontinuation due to AEs.