OBJECTIVE: The purpose of this study was to compare the side effect
+profiles of clozapine and risperidone. METHOD: The subjects were 20
outpatients with schizophrenia or schizoaffective disorder who were
clinically stable on a regimen of clozapine at the time of screening. They
underwent a randomized-order crossover comparison of 6 weeks of risperidone
treatment and 6 weeks of clozapine treatment. Clinical and neurocognitive
variables were assessed by raters blind to medication status, and severity
of side effects was determined from patients' self- reports. RESULTS: Side
effect measures, but not clinical ratings, were significantly different
after 6 weeks of treatment with the two drugs. Patients required more
benztropine for motor effects and complained of more insomnia with
risperidone and more sedation with clozapine. Body weight was higher at the
end of clozapine treatment than at the end of risperidone treatment.
CONCLUSIONS: In this exploratory study, the side effect profiles of
clozapine and risperidone were consistent with the different
pharmacodynamic profiles of the two drugs.