A double-blind, randomised comparative trial of amisulpride versus olanzapine in the treatment of schizophrenia: short-term results at two months.

Objective: To compare the efficacy and safety of the atypical antipsychotics amisulpride and olanzapine in the treatment of acute psychotic exacerbations of schizophrenia.

Design And Setting: A multinational, double-blind randomised clinical trial.

Patients And Treatment: Three hundred and seventy-seven patients with predominantly positive symptomatology were treated for six months with either amisulpride (200-800 mg/d) or olanzapine (5-20 mg/d).

Main Outcome Measures: Short-term results were analysed after two months of treatment. The primary efficacy measure was the change of score on the Brief Psychiatric Rating Scale (BPRS). Other measures of efficacy and safety were also evaluated.

Results: Psychotic symptoms, as measured on the BPRS score, improved with both treatments, amisulpride being equivalent to olanzapine. All BPRS factor scores, as well as depressive symptoms, improved to a similar extent with both treatments. Less than five per cent of patients withdrew for adverse events, and there was no evidence for the emergence of extrapyramidal symptoms with either treatment. Statistically significant greater weight gain (2.7 +/- 3.9 kg) was observed during the study in the olanzapine group, compared with the amisulpride group (0.9 +/- 3.2 kg, p < 0.0001).

Conclusions: Amisulpride and olanzapine show equivalent efficacy at 2 months in the treatment of acute psychotic exacerbations of schizophrenia. Amisulpride offers a significant advantage in preserving body weight.