A popular smoking cessation drug dramatically reduced the amount a heavy drinker will consume, a new Yale School of Medicine study has found. Heavy-drinking smokers in a laboratory setting were much less likely to drink after taking the drug varenicline compared to those taking a placebo, according to a study published online in the journal Biological Psychiatry.

The group taking varenicline, sold as a stop-smoking aid under the name Chantix, reported feeling fewer cravings for alcohol and less intoxicated when they did drink. They were also much more likely to remain abstinent after being offered drinks than those who received a placebo, the study found.

Additionally, there were no adverse effects associated with combining varenicline with alcohol in the doses studied. When combined with low doses of alcohol, varenicline did not change blood pressure or heart rate, nor did it seem to induce nausea or dizziness.

"We anticipate that the results of this preliminary study will trigger clinical trials of varenicline as a primary treatment for alcohol use disorders, and as a potential dual treatment for alcohol and tobacco use disorders," said Sherry McKee, associate professor of psychiatry at the Yale School of Medicine and lead author of the study.

Smokers are more likely to drink alcohol and to consume greater quantities of alcohol, and they are four times more likely to meet criteria for alcohol use disorders. Diseases related to tobacco use are the leading causes of death in alcoholics.

"A medication such as varenicline, which may target shared biological systems in alcohol and nicotine use, holds promise as a treatment for individuals with both disorders" according to McKee.

McKee said that 80% of participants receiving varenicline did not take a drink at all, compared to 30% of the placebo group. The findings suggest that varenicline has the potential to be at least as effective in reducing drinking as naltrexone, another drug found to reduce alcohol consumption in heavy drinkers. Unlike naltrexone, varenicline is not metabolized by the liver and may be safe to use by those with impaired liver function, a frequent consequence of heavy alcohol use, McKee said.

Other Yale authors of the study are; Emily L.R. Harrison, Stephanie S. O'Malley, Suchitra Krishnan-Sarin, Julia Shi, Jeanette M. Tetrault, Marina R. Picciotto, Ismene L. Petrakis, Naralys Estevez, and Erika Balchunas.

The study was funded by the National Institute on Alcohol Abuse and Alcoholism of the National Institutes of Health.