Results of a recent study conducted at the Research Institute of the McGill University Health Centre indicate that naltrexon – one of the few medications that is effectively used in the treatment of alcohol abuse – may only be effective in women and those with a specific gene, the mu-opioid receptor gene (OPRM1).
Alcohol stimulates the release of endorphins in the brain, which bind to opioid receptors, a kind of specialized protein. The activation of these opioid receptors creates feelings of euphoria and pleasure, the same experienced in drunkenness. Naltrexone blocks the receptors and thus decreases the euphoric effects of alcohol. OPRM1 plays a crucial role because it affects the sensitivity of the receptor to the pleasurable effects of alcohol and the ability of naltrexone to diminish these effects, said Marco Leyton of the Department of Psychiatry, the head investigator of the study. However, researchers are as of yet unsure as to why the drug is so effective in women, despite the fact that not all women have the OPRM1 gene.
The benefit of these results is clear: “It will help us give the right medication to the right people,” said Leyton. There is a possibility that further research could lead to a new drug that is effective for everyone, but “since there are probably many pathways that lead to alcoholism, there are probably also multiple treatments that will be needed,” he explained. Moreover, he does not advise that people currently taking naltrexone stop taking it until they have consulted their doctor.
The results will be published in the June 2011 issue of Alcoholism: Clinical & Experimental Research.