Sulpiride augmentation for schizophrenia.

Sulpiride may be used in combination with other antipsychotic drugs in the hope of augmenting effectiveness - especially for those whose schizophrenia has proved resistant to treatment. To evaluate the effects of sulpiride augmentation versus monotherapy for people with schizophrenia. We searched the Cochrane Schizophrenia Group Trials Register (July 2009) which is based on regular searches of CINAHL, EMBASE, MEDLINE and PsycINFO. All relevant randomised clinical trials (RCTs). We extracted data independently. For dichotomous data we calculated relative risks (RR) and their 95% confidence intervals (CI) based on a fixed-effect model. For continuous data, we calculated weighted mean differences (WMD) again based on a fixed-effect model. We included three short-term and one long-term trial (total N=221). All participants had schizophrenia that was either treatment-resistant or with prominent negative symptoms. All studies compared sulpiride plus clozapine with clozapine (+/- placebo), were small and at considerable risk of bias.Short-term data of 'no clinically significant response' in global state tended to favour sulpiride augmentation of clozapine compared with clozapine alone (n=193, 3 RCTs, RR 0.58 CI 0.3 to 1.09).People allocated to sulpiride plus clozapine had more movement disorders (n=70, 1 RCT, RR 48.24 CI 3.05 to 762.56) and an increase in serum prolactin (skewed data, 1 RCT), but less incidence of hypersalivation (n=162, 3 RCTs, RR 0.49 CI 0.29 to 0.83) and less weight gain (n=64, 1 RCT, RR 0.30 CI 0.09 to 0.99). The augmentation of clozapine by sulpiride also caused less appetite loss (n=70, 1 RCT, RR 0.09 CI 0.01 to 0.70, NNT 4 CI 4 to 12, Z=2.31, P=0.02) and less abdominal distension (n=70, 1 RCT, RR 0.10 CI 0.01 to 0.78, NNT 5 CI 4 to 19, Z=2.20, P=0.03).Long-term data showed no significant difference in global state (n=70, 1 RCT, RR 0.67 CI 0.42 to 1.08) and relapse (n=70, 1 RCT, RR 0.85 CI 0.5 to 1.3). Sulpiride plus clozapine is probably more effective than clozapine alone in producing clinical improvement in some people whose illness has been resistant to other antipsychotic drugs including clozapine. However, much more robust data are needed.