Topiramate is an anticonvulsant drug used in the treatment of intractable partial epilepsy.

Topiramate is made by Ortho-McNeil and is sold under the brand name Topamax. It is not currently licensed for use in alcohol dependence.

A recent U.S. study by Dr. Bankole A. Johnson (et al) revealed that topiramate may be helpful in the management of alcohol dependence. This randomised controlled trial was conducted at the University of Texas Health Science Centre and was published in The Lancet (May 17 2003).

Participants in the trial were alcohol dependent and were drinking a minimum of five drinks per day for men, and four for women. All the 150 subjects received behaviour therapy and 20 minute weekly counselling sessions, typically about 20 for three months. Half were given topiramate, and half were given a placebo. The duration of treatment was twelve weeks. During the study those prescribed topiramate were six times as likely as those who took the placebo to abstain from drinking for at least four consecutive weeks. In addition, three months after the end of the treatment programme those taking topiramate were much less likely to be drinking alcohol than those taking placebo. Topiramate therapy also resulted in around a quarter more abstinence days compared with those given placebo. Those who returned to drinking drank around three fewer drinks per day when prescribed topiramate compared to those in the placebo group. Topiramate therapy resulted in around a quarter fewer heavy drinking days. Those who took the placebo were four times as likely as those who took topiramate to drink heavily for 28 consecutive days. Liver enzyme (GTT) levels were also substantially reduced for subjects given topiramate.

The duration of prior heavy drinking had no effect on topiramate's effectiveness.

Topiramate may minimise the euphoric effects of alcohol by markedly reducing the influence of dopamine - believed to be responsible for the pleasurable sensations associated with alcohol. Dopamine activity is minimised by increasing the amount of the neurotransmitter gamma-amino butyric acid, and by blocking the activity of the neurotransmitter glutamate.

Excessive glutamate in the brain is believed to contribute to alcohol withdrawal symptoms such as tremulousness. As topiramate blocks glutamate activity, it may significantly ease withdrawal symptoms from alcohol and thereby reduce cravings for alcohol.

If further, more comprehensive, studies support the above findings it is anticipated that topiramate may become an important new form of treatment for alcohol dependency.