Naltrexone in the treatment of alcohol dependence: a Canadian trial

Alcohol dependence is a prevalent psychiatric disorder affecting approximately 12% of the adult population at some point in their lifetime. Psychosocial treatments are associated with only modest success rates. The first Canadian clinical trial with naltrexone, an opiate antagonist, was conducted to evaluate its safety and usefulness as an adjunctive treatment in the management of alcohol dependence.

One hundred twenty alcohol-dependent individuals were assessed to receive treatment with 50 mg of naltrexone orally for 12 weeks in an open-label trial. Patients were seen biweekly and received a concurrent psychosocial intervention. Treatment was conducted at multiple sites in Canada.

Fifty-four per cent of subjects completed the entire 12 weeks of treatment. During the study, 39% of patients abstained, while of the individuals reporting drinking at baseline, 86% were consuming less alcohol by their final visit. These reductions were accompanied by a significant decrease in craving for alcohol at week 12, as measured by the Obsessive Compulsive Drinking Scale (P<0.01). Naltrexone was well tolerated and no serious adverse events were experienced.

The data lend support to the hypothesis that endogenous opioid activity is involved in the regulation of alcohol intake, and that antagonists of endogenous opioids decrease craving and drinking. Opiate antagonists such as naltrexone are a new strategy in the treatment of alcohol dependence. Naltrexone can be safely given to female and male alcoholics, is acceptable to patients, and plays a role in reducing alcohol consumption and preventing relapse to heavy drinking.