Sulpiride versus placebo for schizophrenia.

Sulpiride is a relatively old antipsychotic drug reputed to have low incidence of adverse effects and an effect on the negative symptoms of schizophrenia. This relatively inexpensive antipsychotic drug has a similar neuropharmacological profile to several novel atypical drugs. To evaluate the effects of sulpiride for schizophrenia and other similar serious mental illnesses in comparison with placebo. We searched the Cochrane Schizophrenia Group Trials Register (September 2008) and references of all identified studies for further trial citations. We contacted pharmaceutical companies and authors of trials for additional information. We included all randomised controlled trials (RCTs) comparing sulpiride with placebo for people with schizophrenia and other types of schizophrenia-like psychoses. The primary outcome of interest was clinically significant response in global state. We independently inspected citations and abstracts, ordered papers, re-inspected and quality assessed these. IMO and JW extracted data. We analysed dichotomous data using random-effects relative risk (RR) and estimated the 95% confidence interval (CI) around this. Where continuous data were included, we analysed this data using random-effects weighted mean difference (WMD) with a 95% confidence interval. Two trials of short duration compare sulpiride with placebo (total n=113). As regards mental state, there were no clear differences between groups for either positive or negative symptoms (n=18, 1 RCT, WMD Manchester scale negative subscore -0.30 CI -1.66 to 1.06; n=18, 1 RCT, WMD SANS 2.90 CI -0.14 to 5.94). Few people left these studies by three months (n=113, 2 RCTs, RR 1.00 CI 0.25 to 4.00). One subscore finding found sulpiride improved social behavior (n=18, 1 RCT, WMD -2.90 CI -5.60 to -0.20). There were no data for many important outcomes such as general functioning, service use or adverse effects. Sulpiride may be an effective antipsychotic drug but evidence of its superiority over placebo from randomised trials is very limited. Practice will have to use evidence from sources other than trials until better evidence is generated.