Zonisamide Enhances Weight Loss, but at a Cost

The antiepileptic drug zonisamide moderately enhances the weight loss achieved with diet and lifestyle counseling, but is associated with a high incidence of adverse events. In a one-year study at Duke University Medical Center, 134 obese women and 91 obese men, all without diabetes mellitus, were randomized to receive daily doses of a placebo, 200 mg of zonisamide, or 400 mg of zonisamide. Change in body weight was −4.0 kg for placebo, −4.4 kg for 200 mg of zonisamide, and −7.3 kg for 400 mg of zonisamide. Gastrointestinal, nervous system, and psychiatric adverse events occurred at a higher incidence with both doses of zonisamide than with placebo.

Funding for the study was provided by the National Institute of Diabetes and Digestive and Kidney Diseases.