Risperidone versus clozapine in treatment-resistant schizophrenia: a randomized pilot study

Abstract

1. The atypical antipsychotic risperidone may constitute an alternative to clozapine, the current treatment of choice for refractory schizophrenia. The objectives of this study were to evaluate the effectiveness of risperidone in comparison to clozapine in everyday practice and to assess the feasibility of a pragmatic trial procedure. 2. Patients were randomly assigned to open-label clozapine or risperidone treatment for 10 weeks and treatment outcomes were assessed blindly. Twenty-one patients were recruited and nineteen entered the randomized phase. 3. Five of 10 participants allocated to clozapine and one of nine risperidone participants dropped out before study completion. Five clozapine patients and six risperidone patients achieved clinical improvement, defined as a 20% decrease in the Positive and Negative Symptom Scale (PANSS) total score. No significant differences between the groups were detected in baseline or endpoint positive or negative symptoms, disease severity, or global or social functioning scores. Patients' opinion on the drugs did not differ between groups. 4. The findings of the intention-to-treat analysis of this study corroborates previous findings that risperidone may be equally effective as clozapine, and supports the feasibility and need of a multicenter randomized pragmatic trial with sufficient power to detect differences between treatments.