Results from a new study suggest that one of the most prescribed medications for alcohol dependence may be more effective in some people. Preliminary results show that naltrexone (Revia), one of the only medications approved for treating people with alcohol abuse problems, may only be effective in women and those with a specific genetic variation. The new study, conducted by researchers from the Research Institute of the McGill University Health Centre (RI MUHC) and McGill University, will be published in the journal Alcoholism: Clinical and Experimental Research.

Previous work suggested that naltrexone only helped some people with alcohol problems, but the reason for that was unclear. “Our results suggest that we might now be able to predict beforehand who will benefit most,” says Dr. Marco Leyton, lead investigator of the study and a researcher in the Mental Illnesses and Addiction axis at the RI MUHC. “We were quite excited to find that our results supported that naltrexone was specifically effective in women and in people who carried a gene related to the brain’s natural morphine system called the mu opioid receptor gene (OPRM1).”

In this study, researchers followed a small group of “social drinkers” in an effort to validate some very preliminary hints that the efficacy of the treatment might be related to gender and a particular gene that may be inherited. These findings could help ensure that we give the right medication to the right people,” says Dr. Leyton, who is also and associate professor in the Department of Psychiatry at McGill.

Researchers and clinicians might be able to determine who might best respond to this treatment, before it was administrated. “If a particular individual with alcohol dependence had these features, we could then say with much more confidence that this is going to help you. For other individuals who don’t have those features, we’ll be able to say, don’t waste your time with this medication, we should try something else for you”, explains Dr. Leyton. “These findings have the potential to improve the quality of treatment for alcohol dependent patients and they could ultimately lead to a form of personalized medicine.”

Alcohol stimulates the release of the brain’s natural opioids, which conveys a feeling of euphoria in individuals when drinking alcohol. There seem to be individual differences in the magnitude of that effect as well as in the sensitivity of the receptors to those natural opioids. “In other words, an opioid receptor blocker, such as naltrexone, might be an effective treatment for people with alcohol problems by decreasing the euphoria of drinking,” explains Ms. Elaine Setiawan, first author of the study and PhD candidate in McGill’s Integrated Program in Neuroscience.

At this point there is no particular reason to think that these findings couldn’t be applied to other groups, such as those with a family history of alcoholism or those with high alcohol craving. But as Dr. Leyton suggests, “further research needs to be done in all sorts of populations and with a much larger sample to better understand the connection between the brain’s opioid system, genetics and different responses to naltrexone.”

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About the paper:
The study entitled “The Effect of Naltrexone on Alcohol’s Stimulant Properties and Self-Administration Behavior in Social Drinkers: Influence of Gender and Genotype” was supported by McGill University, the Canadian Institutes of Health Research (CIHR), and GlaxoSmithKline Inc. The co-authors of the study are Sylvia M.L. Cox of the Department of Neurology and Neurosurgery at McGill University; Robert O. Pihl of the Department of Psychology and the Department of Psychiatry at McGill University; Christina Gianoulakis and Roberta M. Palmour of the Department of Psychiatry at McGill University; and Chawki Benkelfat of the Department of Neurology and Neurosurgery, and the Department of Psychiatry at McGill University.

The Research Institute of the McGill University Health Centre (RI MUHC) is a world-renowned biomedical and health-care hospital research centre. Research is organized by eleven research axes (or programs). Located in Montreal, Quebec, Canada, the Institute is the research arm of the McGill University Health Centre affiliated with the Faculty of Medicine at McGill University. The Institute supports over 600 researchers, 1,000 graduate students, post-docs and fellows devoted to a broad spectrum of fundamental and clinical research. Over 1000 clinical research studies are conducted within our hospitals each year. The Research Institute of the MUHC is supported in part by the Fonds de la recherche en santé du Québec (FRSQ).

About McGill University
McGill University, founded in Montreal, Que., in 1821, is Canada’s leading post-secondary institution. It has two campuses, 11 faculties, 10 professional schools, 300 programs of study and more than 35,000 students. McGill attracts students from more than 150 countries around the world. Almost half of McGill students claim a first language other than English – including 6,200 francophones – with more than 6,800 international students making up almost 20 per cent of the student body.

Media contact:

Julie Robert
Communications Coordinator (Research)
Public Affairs and Strategic Planning, MUHC
Phone: 514 934-1934 ext. 71381
E-mail: .(JavaScript must be enabled to view this email address)

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Contact: Julie Robert
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514-843-1696
McGill University Health Centre