Clozapine and associated diabetes mellitus

Background: Clozapine is an effective therapy for the treatment of refractory psychosis. Clozapine-associated adverse effects include sedation, weight gain, sialorrhea, palpitations, seizures, and hematologic changes such as agranulocytosis. Method: We present a four-case series in which clozapine use was associated with either a de novo onset or severe exacerbation of preexisting diabetes mellitus. Results: The change in glycemic control was not significantly related to weight gain. Three of the patients have been able to continue on clozapine therapy and have experienced a reduction in psychotic symptoms. Conclusion: Patients with a family history of diabetes mellitus or with preexisting diabetes mellitus may need to have blood sugar monitored closely during initiation of clozapine treatment.