Sulpiride may be an effective antipsychotic drug but evidence is limited and data relating to claims for its value against negative symptoms is not trial-based.
The antipsychotic drug sulpiride was formulated over 20 years ago and was marked as having a 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 estimate the clinical efficacy and tolerability of sulpiride.
Electronic searches of Biological Abstracts (1982-1997), CINAHL (1982-1998), Cochrane Schizophrenia Group's Register (March 1998), Cochrane Library (Issue 1, 1998), EMBASE (1980-1998), MEDLINE (1966-1998), PsycLIT (1974-1997), SIGLE (1994-1998), and Sociofile (1974-1997) were supplemented by reference searching, contacting authors and the manufacturers of sulpiride.
All randomised or quasi-randomised clinical trials focusing on the use of different doses of sulpiride or comparing sulpiride to (i) placebo; (ii) typical antipsychotic drugs; or (iii) atypical antipsychotic drugs, for those with schizophrenia or serious mental illness were selected.
Trials were reliably selected and quality rated. Data were independently extracted, by two reviewers (BGOS, MF), and analysed on an intention-to-treat basis. It was assumed that people who did not complete the follow up had no improvement. Authors of trials were contacted for additional and missing data. Relative risk (RR) and 95% confidence intervals (CI) of dichotomous data were calculated with the random effects model and weighted mean difference (WMD) was calculated for continuous data.
The review currently includes 18 studies (30 citations). Studies are generally small and of poor quality. Limited evidence suggests that there is little difference between sulpiride and other drugs although the incidence of side effects may be less for sulpiride. There are no clear findings relating to negative symptoms.