Amisulpride is an "atypical" antipsychotic associated with low weight gain

Rationale. It is possible that amisulpride, with its unique receptor binding profile, is not associated with significant weight gain, a serious side effect of most "atypical" antipsychotic drugs. While most "atypicals" have a high affinity for both dopamine and serotonin receptors, amisulpride has only dopamine receptor action. Objectives. To analyse the weight gain associated with amisulpride. Methods. A pooled database of prospective randomised amisulpride studies was analysed. The mean weight gain after 10 weeks of treatment was estimated by regression analysis. Results. Eleven studies with a total of 1422 patients were pooled, providing 1392 patients who were eligible for evaluation. In the main analysis of all effective doses (50-1200 mg/day) the mean weight gain associated with amisulpride at 10 weeks was 0.8 kg, 95% CI (0.48-1.18). Linear regression showed no dependence of weight gain on daily dose levels (P=0.7). When patients with mean daily doses below 400 mg/day were excluded in a sensitivity analysis, the mean weight gain at ten weeks was again 0.80 kg, 95% CI (0.47-1.16) with n=874. The mean weight gain at study endpoints in 1-year studies was 1.4 kg, 95% CI (0.85-1.90), n=548. Conclusion. Amisulpride is an atypical antipsychotic associated with low weight gain.