Genetics Plays Role in Efficacy of Naltrexone
Naltrexone more strongly blunts effects of alcohol in people with the G allele of the OPRM1 gene
FRIDAY, Sept. 28 (HealthDay News) -- Alcohol-induced highs are blunted more strongly by naltrexone in patients who have at least one copy of the G allele of the OPRM1 gene, according to study findings published in the September issue of the Archives of General Psychiatry.
Lara A. Ray, Ph.D., of Brown University in Providence, R.I., and Kent E. Hutchison, Ph.D., of the University of Colorado in Boulder, conducted a double-blind, placebo-controlled study of 40 heavy drinkers who were not seeking treatment, who received either 50 mg naltrexone or placebo, and then were monitored for the effects of intravenous alcohol intake.
Among the sample, 15 subjects had at least one copy of the G variant, while the other 25 were homozygous for the A allele. Those with the G allele reported stronger alcohol-induced highs with rising intoxication levels than those without the G allele. Naltrexone dampened the stimulation, positive mood, craving and enjoyment effects of alcohol and the drug was more effective among subjects with the G allele.
Understanding the role of genetic moderators and mechanism of action of drug therapies is more important than ever, the authors write. "Focusing on the neurobiologic aspects of alcohol-induced reward as a mechanism of action and its underlying genetic basis may be especially useful in characterizing which subgroups of patients are more likely to respond to a pharmacotherapy," they conclude.