Augmentation of Clozapine With Amisulpride in Patients With Treatment-Resistant Schizophrenia An Open Clinical Study

Background: Therapeutic options for patients with treatment-resistant schizophrenia are limited. In such cases, a combination of atypical antipsychotic drugs is an often used strategy. We tested the hypothesis that the combination of amisulpride and clozapine would lead to long-term improvement in this patient group. Objective: 15 patients with treatment-resistant schizophrenia participated in this open clinical trial and received a combination of amisulpride and clozapine. Patients had to have remained on a stable dose of clozapine for at least 6 months in order to ensure a reasonable opportunity to respond to clozapine monotherapy. Clinical status was evaluated at baseline, and 3, 6 and 12 months' follow-up, using the Brief Psychiatric Rating Scale (BPRS). Results: All patients completed 12 months' combination treatment. The mental state of 11 patients (73.3%) was improved and there was a significant reduction in the mean BPRS score over the 12 months of combination treatment. The augmentation of amisulpride in clozapine treated patients did not result in a corresponding increase in side effects. The combination allowed a mean reduction of 12.8% of the daily clozapine dose. Conclusions: The combined application of clozapine and amisulpride follows a neurobiological rationale and appears to be safe and well tolerated, without increasing the risk of side effects (German J Psychiatry 2006; 9: 17-21).