News Release - Gene Variant Predicts Medication Response in Patients with Alcohol DependenceFor Immediate Release:
Thursday, February 7, 2008
Patients with a certain gene variant drank less and experienced better overall clinical outcomes than patients without the variant while taking the medication naltrexone, according to an analysis of participants in the National Institutes of Health's 2001-2004 COMBINE (Combined Pharmacotherapies and Behavioral Interventions for Alcohol Dependence) Study. About 87 percent of patients with the variant who received naltrexone. experienced good outcomes, compared with about 49 percent of those who received a placebo. About 55 percent of patients without the variant experienced a good outcome regardless of whether they received naltrexone or placebo. Good outcome was defined as abstinence or moderate drinking without related problems, according to an article in the Feb. 4 issue of the Archives of General Psychiatry
Drinking alcohol increases the release of endogenous opioids, compounds that originate in the body and promote a sense of pleasure or well-being. An opioid antagonist, naltrexone blocks brain receptors for endogenous opioids, making it easier for patients to remain abstinent or stop quickly in the event of a slip. In clinical studies, naltrexone has been shown to reduce relapse and craving for alcohol in some but not all treated patients. Earlier studies had suggested that a specific DNA variant of the opioid receptor gene (OPRM1) might have role in patients' response to naltrexone.
"Analysis of the large COMBINE patient population increases confidence that the OPRM1 variant is in part responsible for positive responses to naltrexone. This study points to the promise of research on gene-medication interactions to refine treatment selection, improve clinical results, and inform ongoing medications development," said National Institute on Alcohol Abuse and Alcoholism (NIAAA) director Ting-Kai Li, M.D.
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