Drinking and medication

NEW YORK (Reuters Health) - A drug that blocks opioid receptors in the brain may help curb problem drinking, even without extensive alcohol counseling, a study suggests. Researchers in Finland found that a medication called nalmefene helped problem drinkers cut down on their heavy drinking. Over six months of treatment, the average number of "heavy drinking days" fell by nearly half among patients randomly assigned to take nalmefene.

In addition, the benefits came without any significant behavioral therapy, the study authors report in the journal Alcoholism: Clinical & Experimental Research.

Study patients received advice on reducing their drinking, and their treatment progress was monitored, but they did not have any formal psychological counseling.

Nalmefene belongs to a class of drugs known as opioid antagonists, which means they block the brain receptors that are stimulated by heroin and other opiate drugs. Opioid antagonists also appear to curb the urge to drink; naltrexone, another medication in this class, is already used to treat alcoholism.

Nalmefene is not yet approved in the U.S. for treating alcohol abuse.
For the current study, Finnish researchers randomly assigned 403 people with alcohol abuse problems to take either nalmefene or a placebo (inactive pills). They were instructed to take the pills as needed, when drinking seemed "imminent."
At the start of the study, participants reported drinking heavily on an average of 15 to 16 days out of the month. During treatment, this average fell to eight to nine days in the nalmefene group, and 10 to 12 days in the placebo group.

The researchers verified patients' reported drinking levels with blood tests that measured certain substances indicative of alcohol use.
There was also evidence that nalmefene works over the long term. After 28 weeks of treatment, the researchers assigned some nalmefene patients to keep taking the medication for another 24 weeks, while the rest were switched to a placebo.
Overall, placebo patients tended to return to more frequent heavy drinking, while nalmefene patients maintained their lower levels of alcohol use.
The findings suggest that nalmefene "has a robust and sustained effect in reducing harmful heavy drinking in a large study population," lead study author Dr. Sakari Karhuvaara said in a statement.
Karhuvaara is a former researcher with Turku, Finland-based Biotie Therapies Corp., which makes nalmefene and funded the current study.
It's "particularly noteworthy," Karhuvaara and his colleagues write, that the study patients cut down on their heavy drinking even though they were being treated by their primary care doctors, with little alcohol counseling.

The study found no serious side effects of the drug, but one-quarter to one-third of nalmefene patients suffered nausea, insomnia, fatigue or dizziness.