Amisulpride versus other atypical antipsychotics for schizophrenia

Background In many countries of the industrialised world second generation (atypical) antipsychotics have become first line drug treatments for people with schizophrenia. The question as to whether, and if so how much, the effects of the various second generation antipsychotics differ is a matter of debate. In this review we examine how the efficacy and tolerability of amisulpride differs from that of other second generation antipsychotics. Objectives To evaluate the effects of amisulpride compared with other atypical antipsychotics for people with schizophrenia and schizophrenia‐like psychoses. Search methods We searched the Cochrane Schizophrenia Group Trials Register (April 2007) which is based on regular searches of BIOSIS, CINAHL, EMBASE, MEDLINE and PsycINFO. We updated this search in July 2012 and added 47 new trials to the awaiting classification section. Selection criteria We included randomised, at least single‐blind, trials comparing oral amisulpride with oral forms of aripiprazole, clozapine, olanzapine, quetiapine, risperidone, sertindole, ziprasidone or zotepine in people with schizophrenia or schizophrenia‐like psychoses. Data collection and analysis We extracted data independently. For continuous data we calculated weighted mean differences (MD), for dichotomous data we calculated relative risks (RR) and their 95% confidence intervals (CI) on an intention‐to‐treat basis based on a random effects model. We calculated numbers needed to treat/harm (NNT/NNH) where appropriate. Main results The review currently includes ten short to medium term trials with 1549 participants on three comparisons: amisulpride versus olanzapine, risperidone and ziprasidone. The overall attrition rate was considerable (34.7%) with no significant difference between groups. Amisulpride was similarly effective as olanzapine and risperidone and more effective than ziprasidone (leaving the study early due to inefficacy: n=123, 1 RCT, RR 0.21 CI 0.05 to 0.94, NNT 8 CI 5 to 50). Amisulpride induced less weight gain than risperidone (n=585, 3 RCTs, MD ‐0.99 CI ‐1.61 to ‐0.37) or olanzapine (n=671, 3 RCTs, MD ‐2.11 CI ‐2.94 to ‐1.29). Olanzapine was also associated with a higher increase of glucose (n=406, 2 RCTs, MD ‐7.30 CI ‐7.62 to ‐6.99). There was no difference in terms of cardiac effects and extra pyramidal symptoms (EPS) compared with olanzapine (akathisia: n= 587, 2 RCTs, RR 0.66 CI 0.36 to 1.21), compared with risperidone (akathisia: n=586, 3 RCTs, RR 0.80 CI 0.58 t