A person’s genetic makeup determines the effectiveness of an experimental medication for alcoholism, according to a new study supported by the National Institute on Alcohol Abuse and Alcoholism (NIAAA).
“This study represents an important milestone in the search for personalized treatments for alcohol dependence,” says NIAAA Acting Director Kenneth R. Warren, Ph.D. A report of the findings appears online in the American Journal of Psychiatry.
Researchers sought to determine whether the medication ondansetron (currently used for nausea and vomiting during chemotherapy) could help alcohol-dependent individuals cut back on compulsive drinking.
Ondansetron blocks receptors for serotonin, a brain chemical which helps control the rewarding effects of alcohol. The research shows that variants in the gene that encodes a protein regulating serotonin between nerve cells can drastically reduce compulsive drinking.
Two serotonin transporter variants, called LL and TT, have been associated with severe drinking problems. For the study, genetic analysis was used to first determine which serotonin transporter gene variant each participant was carrying; each individual was then randomly given a treatment regimen for either ondansetron or placebo.
Among participants with the LL genotype, those who took the placebo continued to have an average of five or more drinks per day. However, the subjects who took ondansetron reduced their average number of daily drinks to less than five; they also had far more days of abstinence compared to those who received placebo.
The effects of ondansetron were even more prominent in subjects who carried both the LL and TT gene variants. However, for those participants who lacked the LL variant, ondansetron had no effect.
“By being able to do genetic screening beforehand, clinicians can eliminate a great deal of the trial and error approach to prescribing medicine,” says Bankole Johnson, M.D., Ph.D., professor and chair of the Department of Psychiatry and Neurobehavioral Sciences at the University of Virginia, Charlottesville.
“Personalized medicine allows them to better predict a successful treatment option.”
Source: National Institutes of Health