Ondansetron could help sufferers of the eating disorder bulimia nervosa, according to a report published in the Lancet (2000;355:792). The study authors found that when sufferers were given the anti-nausea drug, it reduced binge-vomiting episodes by half.
The American researchers propose that, as a result of chronic self-induced vomiting, afferent vagal fibres, which are involved in satiety, become hyperactive. This results in a loss of voluntary control, with patients feeling driven to engage in binge eating and vomiting, the authors believe. Their hypothesis was that ondansetron, a 5HT3 antagonist, might reduce abnormal afferent vagal activity. To test this, 26 women suffering from chronic bulimia nervosa were treated with either ondansetron (24mg daily) or placebo for four weeks. This randomised, double-blind phase followed a one-week, single-blind placebo phase.
At the end of the trial, women in the ondansetron group had on average one binge-vomiting episode per day compared with an average of two episodes per day in the placebo group. Patients receiving ondansetron were also eating a greater number of meals without vomiting.
Professor Patricia Faris (lead author of the study, department of psychiatry, University of Minnesota medical school) says: "Our work presents evidence that engaging in bulimic behaviours may induce a significant physiological change in the nervous system."
Dr Alexander Kiss (department of psychosomatics, university hospital, Basle), writing in an accompanying commentary (ibid, p769), welcomes the new treatment but says: "There is no doubt that ondansetron reduces bulimic symptoms, but some questions remain about how the drug works and whether it is really a treatment option for patients with bulimia."
A spokesperson for Glaxo Wellcome, manufacturer of ondansetron (Zofran), told The Journal on March 7 that the research was interesting and this use of ondansetron warranted further investigation.