Genetic targets help alcohol addiction, study finds
Alcoholics who are tested for genotype specificity prior to receiving ondansetron may have significantly improved outcomes, according to a report published in the March 2011 issue of American Journal of Psychiatry.
In a double-blind controlled trial, a cohort of 283 people with alcohol addiction were randomized by their specific genotype of the serotonin transporter gene: the 5'-regulatory region of the 5-HTT gene (LL/LS/SS) and a polymorphism in the 3'-untranslated region. Study subjects were given either ondansetron (4 μg/kg twice daily) or placebo for 11 weeks, and also received cognitive behavioral therapy. People with the LL genotype who received ondansetron reported a lower mean number of drinks per drinking day (-1.62) and a higher percentage of days abstinent (11.27%) than participants who received placebo. Individuals with non-LL genotype patterns receiving ondansetron responded less favorably than the LL group.
Results from this investigation demonstrate the direct relationship of an alcohol addiction patient's genetic profile and his/her ability to respond to therapy. Based on the results of their study, investigators "propose a new pharmacogenetic approach using ondansetron to treat severe drinking and improve abstinence in alcoholics."
The study further confirms the benefits of genetic targeting for drug therapies, according to lead investigator Bankole A. Johnson, MD, PhD, DSc, chairman of the department of psychiatry and neurobehavioral sciences at the University of Virginia School of Medicine, Charlottesville, Va.
"One side of targeting treatment is tailoring the efficacy of response, that is, giving medicine to people who respond to the medication. The other side of this approach is to have no side effects and no adverse events," said Dr Johnson.
From a payer perspective, Dr Johnson said, "Even if you look at the most successful psychiatric drugs, not much more than half of the people taking a medicine, sometimes less than that, respond to it. This is a huge waste in medical costs, hospital costs, drug expense, and it doesn't help patients."
Johnson BA, Ait-Daoud N, Seneviratne C, et al. Pharmacogenetic approach at the serotonin transporter gene as a method of reducing the severity of alcohol drinking. Am J Psychiatry. 2011;168:265–275.