Metabolic consequences of using low-dose quetiapine for insomnia in psychiatric patients.

Quetiapine is frequently prescribed for insomnia that is comorbid with psychiatric disorders, but there has been no documentation of metabolic adverse effects associated with this practice. The objective of this study was to document changes in weight, body mass index, and waist circumference that occurred when low-dose quetiapine was used at bedtime for insomnia. The study was a retrospective chart review conducted at a community mental health center. Patients were non-elderly (19-65 years old) psychiatric patients who received quetiapine at < or =200 mg at bedtime for the explicit indication of insomnia. Forty-three patients were included in the study. Weight and BMI increased by an average of 4.9 lb. (P = 0.037) and 0.8 points (P = 0.048), respectively. Males experienced statistically significant increases in weight and BMI, and Caucasians experienced a statistically significant increase in BMI. There were no significant differences between baseline and endpoint metabolic parameters when examined by baseline BMI, age category, psychiatric diagnosis, or concomitant psychotropic medication. Despite the low doses typically used when quetiapine is prescribed for insomnia, metabolic adverse effects can occur and should be considered in the overall benefit to risk analysis.