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UNC News Service, April 5, 2005.

CHAPEL HILL — Research led by the University of North Carolina at Chapel Hill with 23 other sites nationwide has found that long-acting injections of the drug naltrexone, combined with psychotherapy, significantly reduced heavy drinking in patients being treated for alcohol dependence.

Study results showed that the median number of heavy drinking days was reduced from 19 days in the month prior to the study to three days per month over the six months of treatment.

The study results will be published in the April 6 issue of the Journal of the American Medical Association. The lead author is Dr. James C. Garbutt, a professor in the UNC School of Medicine’s department of psychiatry and a researcher in UNC’s Bowles Center for Alcohol Studies.

“It is so important that our field find new treatments for alcohol dependence,” Garbutt said. “Long-acting naltrexone represents one promising new development for treatment, and I hope that it can play a role in helping some of the millions of individuals who suffer from alcohol dependence.”

Alcohol dependence is a major public health problem, ranking as the fourth leading cause of disability worldwide, as reported by the World Health Organization’s Global Burden of Disease project. Nationwide, it is believed to contribute to more than 100,000 preventable deaths a year.

Naltrexone was approved in pill form by the U.S. Food and Drug Administration in 1994 and belongs to a class of drugs called opioid antagonists, for treating alcohol dependence. Although many clinical trials have shown that oral naltrexone can be effective in treating alcohol dependence, its use in clinical practice has been limited, in part because the drug was given as a pill that patients have to take daily.

“Adherence to a daily oral medication is a general problem in medicine, and it is an even greater problem among patients with addictive disorders,” said Garbutt. “The study showed long-acting naltrexone provides a firm basis for combination with counseling and is effective in treating participants who are actively drinking but are motivated to reduce their drinking.”

A total of 627 alcohol-dependent patients were randomly assigned to receive either an injection of long-acting naltrexone or a placebo injection; 624 ultimately received at least one injection. All participants received low-intensity counseling consisting of 12 sessions during the six-month study, in addition to study medication.

Long-acting naltrexone was associated with a reduction in heavy drinking within the first month of treatment, and this response was maintained over the six-month treatment period. In addition, long-acting naltrexone was generally well tolerated and side effects were predominantly mild and decreased over time. The three most common side effects reported were nausea, headache and fatigue.

The study was one of the largest trials of a medication for alcohol dependence, and the 24 sites nationwide included public hospitals, private and Veterans Administration clinics and tertiary-care medical centers. Other study authors included researchers from the medical schools at the University of Connecticut, Yale University, the University of Pennsylvania and Harvard University, and from Alkermes Inc., a biotechnology company based in Cambridge, Mass., that manufactures the long-acting naltrexone formulation (trade name: Vivitrex) used in the study.

This study was funded and conducted by Alkermes and designed by Alkermes with suggestions from the investigators. Data were collected, monitored, managed and analyzed by Alkermes clinical and regulatory personnel and were interpreted by study authors with input from Alkermes clinical and statistical staff.