Addiction Drug May Promote Weight Loss

Author: Madeline Ellis

The millions of Americans who are overweight or obese are putting their health in jeopardy. Obesity is the second leading cause of preventable death, and can raise your risk of developing heart disease, cancer, diabetes, arthritis, asthma and even gum disease. The underlying causes of obesity are numerous, from genetic disposition to binge eating, which may be caused by the same brain changes responsible for addiction. This link prompted researchers to test a potential addiction drug on lab rats bred to be obese-with surprising results.

Researchers at the U.S. Department of Energy's Brookhaven National Laboratory tested the drug, called vigabatrin or GVG, in 50 rats, some of which were bred obese and some were of normal weight. The animals were either given injections of various amounts of vigabatrin or a placebo for up to 40 days. The genetically obese rats lost up to 19 percent of their body weight, and normal-weight rats lost 12 to 20 percent of their body weight. "Our results appear to demonstrate that vigabratrin induced satiety in these animals," said Amy DeMarco, who worked on the study. "When we gave GVG, they would steadily lose weight, and when we took them off GVG, they would steadily gain weight," she told Reuters Health.

Vigabratrin works by preventing the increase of dopamine, a chemical produced in the brain that has been linked to addiction and overeating. "Given the growing obesity epidemic, we felt that examining vigabatrin's therapeutic efficacy for obesity was particularly relevant," said lead researcher Dr. Stephen Dewey, who has conducted more than 20 years of preclinical research with the medication. "A fairly significant proportion of subjects who are obese suffer from something called binge eating disorders. They binge-eat based on cues. They see a cake, they smell a hamburger and they crave and they start to eat. One of the great things about this drug is it stops this."

Vigabatrin was originally made by Sanofi Aventis and is sold as Sabril in Canada, Mexico and Britain. Ovation Pharmaceuticals currently hold the U.S. rights to develop vigabatrin as a treatment for epilepsy. It is also currently in U.S. Food and Drug Administration (FDA)-approved Phase II clinical trials as a possible treatment against cocaine and methamphetamine addiction. "The fact that these results occurred in genetically obese animals offers hope that this drug could potentially treat severe obesity," Dr. Dewey said. "This would appear to be true even if the obesity results from binge eating, as this disorder is characterized by eating patterns that are similar to drug-taking patterns in those with cocaine dependency."

The study was published in the August 20 issue of the journal Synapse.