Comparison of antipsychotic dose equivalents for acute bipolar mania and schizophrenia

Question

Are antipsychotic dose equivalents between acute mania and schizophrenia the same?

Study selection and analysis

Six databases were systematically searched (from inception to 17 September 2022) to identify blinded randomised controlled trials (RCTs) that used a flexible-dose oral antipsychotic drug for patients with acute mania. The mean and SD of the effective dose and the pre–post changes in manic symptoms were extracted. A network meta-analysis (NMA) under a frequentist framework was performed to examine the comparative efficacy between the antipsychotics. A classic mean dose method (sample size weighted) was used to calculate each antipsychotic dose equivalent to 1 mg/day olanzapine for acute mania. The antipsychotic dose equivalents of acute mania were compared with published data for schizophrenia.

Findings

We included 42 RCTs which enrolled 11 396 participants with acute mania. The NMA showed that risperidone was superior to olanzapine (reported standardised mean difference: –022, 95% CI –0.41 to –0.02), while brexpiprazole was inferior to olanzapine (standardised mean difference: 0.36, 95% CI 0.08 to 0.64). The dose equivalents to olanzapine (with SD) were 0.68 (0.23) for haloperidol, 0.32 (0.07) for risperidone, 0.60 (0.11) for paliperidone, 8.00 (1.41) for ziprasidone, 41.46 (5.98) for quetiapine, 1.65 (0.32) for aripiprazole, 1.23 (0.20) for asenapine, 0.53 (0.14) for cariprazine and 0.22 (0.03) for brexpiprazole. Compared with the olanzapine dose equivalents for schizophrenia, those of acute mania were higher for quetiapine (p<0.001, 28.5%) and aripiprazole (p<0.001, 17.0%), but lower for haloperidol (p<0.001, –8.1%) and risperidone (p<0.001, –15.8%).

Conclusions

Antipsychotic drugs have been considered first-line treatment for acute mania, warranting specific dose equivalence for scientific and clinical purposes.