Zonisamide in the Treatment of Binge Eating Disorder With Obesity: A Randomized Controlled Trial

Objective: Binge eating disorder (BED) is associated with obesity. Zonisamide is a novel antiepileptic drug associated with weight loss. The purpose of this study was to evaluate zonisamide in the treatment of BED associated with obesity.

Method: In this 16-week, single-center, randomized, double-blind, placebo-controlled, flexible-dose (100-600 mg/day) trial, 60 outpatients with DSM-IV-TR BED received zonisamide (N = 30) or placebo (N = 30). The primary outcome measure was weekly frequency of binge eating episodes. The primary analysis of efficacy was a longitudinal analysis of the intent-to-treat sample, with treatment-by-time interaction as the effect measure. Patients were enrolled from September 5, 2003, through October 1, 2004.

Results: Compared with placebo, zonisamide was associated with a significantly greater rate of reduction in binge eating episode frequency (p = .021), body weight (p < .001), BMI (p = .001), and scores on the Clinical Global Impressions-Severity scale (p < .001), Yale-Brown Obsessive Compulsive Scale Modified for Binge Eating (p < .001), and Three Factor Eating Questionnaire disinhibition scales (p < .001). Plasma ghrelin concentrations increased with zonisamide but decreased with placebo (p = .001). The mean (SD) zonisamide daily dose at endpoint evaluation was 436 (159) mg/day. Twelve patients (N = 8 receiving zonisamide, N = 4 receiving placebo) discontinued because of adverse events. The most common reasons for discontinuing zonisamide were accidental injury with bone fracture (N = 2), psychological complaints (N = 2), and cognitive complaints (N = 2).

Conclusion: Zonisamide was efficacious, but not well tolerated, in the short-term treatment of BED associated with obesity.

Clinical Trials Registration: ClinicalTrials.gov identifier NCT00221442