Amisulpride versus placebo in the medium-term treatment of the negative symptoms of schizophrenia

Background Amisulpride is a substituted benzamide with high selectivity for dopamine D-2 and D-3 receptors. The purpose of the study waste evaluate the effect of 100 mg amisulpride in patients with predominantly negative symptoms of schizophrenia. Method This was a multi-centre, randomised, parallel-group double-blind study Patients received either amisulpride (100 mg/day) or placebo over a six-month treatment period. Results A total of 141 patients were included, 69 received amisulpride, 72 placebo. Fifty-eight patients (41%) had received neuroleptic treatment prior to inclusion. The percentage of amisulpride patients completing the study (55%) was significantly higher than that with placebo (32%), and drop-out rates due to lack of efficacy were 27% with amisulpride and 47% with placebo. All efficacy assessments were statistically in favour of amisulpride compared with placebo. The overall incidence of extrapyramidal symptoms was comparable in both groups; only five patients star-ted anti-Parkinsonian treatment during the study (one in the placebo and four in the amisulpride group). Conclusion Amisulpride is effective in the medium-term treatment of schizophrenic patients with predominantly negative symptoms.