Amisulpride as adjunct to clozapine in treatment-resistant schizophrenia and schizoaffective disoder: An open-label pilot study

Abstract

Background. Although clozapine is the treatment of choice for treatment-resistant schizophrenia, many patients remain symptomatic despite adequate treatment with this medication. One suggested strategy to improve efficacy has been the addition of a potent D2 blocker such as amisulpride to treatment with clozapine. Methods. In this study, 20 subjects who were treatment-resistant to conventional antipsychotics and who were still symptomatic despite adequate treatment with clozapine received amisulpride as adjunctive treatment. After baseline assessment all subjects were titrated to amisulpride 400 mg per day and then reassessed after 8 weeks by a blinded rater. Results. Analysis showed statistically significant improvements in PANSS (Positive and Negative Symptom Scale) total score (t = 3.49, df = 18, p = 0.003), PANSS negative subscale score (t = 3.22, df = 18, p = 0.005), and PANSS depression factor score (t = 3.89, df = 19, p = 0.001). Discussion. This study suggests that addition of the second- generation antipsychotic amisulpride to a stable treatment regimen with clozapine may offer additional benefits in terms of negative and depressive symptoms.