Treating Bulimia Nervosa with Topiramate

Along with repeated episodes of uncontrolled binge eating and purging, patients with bulimia nervosa must deal with an obsession with food and body weight, distorted body image, low self-esteem, high anxiety, and depression. They struggle each day with the psychological impact of the illness, and binge-eating and purging may give temporary relief of the emotional pain.

Recent treatment approaches have included a multimodal approach with tricyclic antidepressants and selective serotonin reuptake inhibitors, as well as cognitive behavioral therapy and interpersonal therapies. Dr. Dawson W. Hedges and colleagues report that in a recent industry-supported study of outpatients with bulimia nervosa, use of the antiepileptic agent topiramate improved binge-purge behaviors and led to improved self-esteem, eating attitudes, and body image, while diminishing anxiety and depression (J Clin Psychiatry 2003; 64:1449).

Study design

Thirty-five outpatients received topiramate, starting at a dosage of 25 mg/day; this dosage was titrated by 25 to 50 mg/week to a maximum dosage of 400 mg/day. A control group of 34 patients were given a placebo. All patients were tested with the Eating Attitudes Test (EAT), the Eating Disorders Inventory (EDI), and the Hamilton scales for anxiety and depression (HAM-A and HAM-D). All but one patient were female (1 male was included in the topiramate group), and the mean age (29.6 years) was similar in both groups.

Antiepileptic agent led to improvements on the EAT and EDI

On the EDI, patients treated with topiramate showed a greater change in mean score in 5 scales than patients treated with placebo; those in the topiramate group also had a statistically greater change in mean score on the bulimia/food preoccupation and dieting subscales of the EAT than did patients in the placebo group. Those treated with topiramate had significantly greater reductions than those in the placebo group in HAM-A and HAM-D scores and in both binge and purge behaviors. The mean number of days on which patients binged and/or purged fell 44.8% in the topiramate group, compared with 10.7% in the placebo group.

The authors report that baseline EDI scores for ineffectiveness, interpersonal distrust, interoceptive awareness and maturity fears were already at normal levels in both groups, which may explain why these values did not change significantly with treatment.

The most common side effects reported among the topiramate group were fatigue in 32% (versus 24% in the placebo group), flu-like symptoms in 29% (18% in the placebo group), and paresthesias in 24% (6% in the placebo group).

A therapeutic effect beyond slowing binge eating and purging

According to Dr. Hedges and colleagues, improvements in the two eating disorder scales suggest a therapeutic effect that goes beyond moderating binge eating and purging behaviors. They feel that the results on the EAT test suggest relief from obsession with food, while the EDI results show a lessening of obsession with food and body weight.