Switching clozapine responders to olanzapine

Background; Clozapine is an atypical antipsychotic indicated for the manage ment of severely ill patients with schizophrenia who have failed to respond adequately to standard drug treatment. The significant risk of agranulocyt osis and seizure associated with clozapine has led to the restrictions in i ts use. Additionally, drug-induced sedation, sialorrhea, enuresis, and weig ht gain are often cited as problematic consequences of clozapine treatment. Our primary objective was to determine the effectiveness and safety of a m ethod of slow cross-titration from clozapine to olanzapine among patients r esponsive to clozapine treatment but experiencing medication-induced advers e events. Method: Changes in symptomatology, mood, subjective response, and safety we re examined in 20 outpatients meeting DSM-IV criteria for schizophrenia or schizoaffective disorder who converted from clozapine to olanzapine. Patien ts were considered clozapine-responsive as evidenced by improved social fun ction and decreased symptoms with clozapine therapy; however, they were int erested in alternative pharmacologic treatment because of clozapine-related side effects. Results: Equivalent efficacy of olanzapine to clozapine was found in 90% of the patients (18/20) in the study group, without rehospitalization or suic idal behavior in any of the patients. Also notable was a reduction in drug- induced side effects and improved subjective response to pharmacotherapy. Conclusion; The successful conversion from clozapine to olanzapine has the potential to provide great benefits for the patient, including reducing dru g-induced side effects while maintaining symptom control. These preliminary results suggest that further research on converting clozapine responders t o olanzapine is warranted.