Study objective: To explore the clinical characteristics of hyperglycemia in patients treated with risperidone.
Design: Pharmacovigilance survey of spontaneously reported adverse events in risperidone-treated patients, with reports of haloperidol-associated hyperglycemia used as a control.
Setting: Government-affiliated drug evaluation center.
Intervention: The Food and Drug Administration MedWatch surveillance program was queried (risperidone, 1993-February 2002; haloperidol, late 1970s-February 2002) and results pooled with published cases.
Measurements and main results: We identified 131 reports of risperidone-associated hyperglycemia in addition to seven reports of patients with hyperglycemia who received combined risperidone-haloperidol therapy and six reports of acidosis that occurred in the absence of hyperglycemia. We found 13 reports of haloperidol-associated hyperglycemia and 11 reports of acidosis without hyperglycemia. Of the reports of risperidone-associated hyperglycemia (monotherapy), 78 patients had newly diagnosed hyperglycemia, 46 had exacerbated preexisting diabetes, and 7 could not be classified. Mean +/- SD age was 39.8 +/- 17.4 years (range 8-96 yrs). Patients with new-onset diabetes (mean +/- SD age 34.8 +/- 15.7 yrs) were younger than those with preexisting diabetes (mean +/- SD age 48.8 +/- 17.5 yrs). The overall male:female ratio was 1.5. In most patients, hyperglycemia appeared within 3 months of the start of risperidone therapy. Severity of disease ranged from mild glucose intolerance to diabetic ketoacidosis or hyperosmolar coma. Twenty-six patients with acidosis or ketosis were reported. Four patients died.
Conclusion: Atypical antipsychotic treatment may unmask or precipitate hyperglycemia. Although such cases attributed to clozapine or olanzapine are more numerous than those associated with risperidone, the number for risperidone-associated hyperglycemia is relatively higher than that observed with the conventional neuroleptic haloperidol.