"Remarkably, all 150 patients were enrolled into this clinical trial while they were still drinking heavily (defined as more than 5 standard drinks a day for men and more than 4 for women)," said Dr. Bankole A. Johnson, study coauthor. "Next, these patients were randomized to receive either oral topiramate (up to 300 mg a day) or placebo for 3 months along with a minimum intervention behavioral treatment. Patients who took topiramate were 6 times more likely than those who received placebo to be continuously abstinent for at least 1 month during the 3-month trial. Over the same period, those taking the placebo were 4 times more likely to drink heavily for an entire month during the trial."

Alcohol-dependent patients frequently have liver disease, one indicator of which is a rise in the plasma level of gamma glutamyl transferase. "It is of considerable clinical importance that topiramate was superior to placebo at significantly reducing the plasma [enzyme] levels during the trial," Johnson said. "Further, topiramate was shown to be effective treatment for all types of alcohol-dependent patients."

Leading researchers in the field found the findings to be significant for treatment of alcoholism. "The strength of their findings is likely to change the direction of clinical alcoholism treatment and will be welcome news for practitioners," said Robert Malcolm, M.D., who had not been involved with the research. He said "the results of Professor Johnson's study suggest that topiramate, even in low doses early in treatment, has the capacity to ameliorate the turbulence of anxiety and mood instability that accompanies cessation from alcohol. Topiramate also produced a robust effect on improving maintenance of abstinence and reduced alcohol use. A single pharmacologic agent that enhances early abstinence, stabilizes mood and anxiety symptoms, and promotes long-term abstinence with only modest psychosocial intervention is indeed a remarkable treatment advance."

Otto Michael Lesch, M.D., Ph.D., of the European Society of Biomedical Research on Alcoholism, said scientists should confirm the finding in an American-European-Australian trial. He said "this study is much better than other studies," but noted that further clinical trials are needed to identify the optimum dosage of topiramate in the treatment of alcohol dependence.