'As we learn more about how the brain is affected by alcohol, we are discovering how best to provide treatment -- like adding a safe medication to counseling. A long-acting injectable, which eliminates the burden of daily pill taking, will open new doors for our patients and give hope to them and their families.'

Study results show 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, report researchers from the University of Pennsylvania School of Medicine, who conducted the study in conjunction with 23 other sites across the United States.

100,000 Preventable Deaths Each Year

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

"It is so important that our field find new treatments for alcohol dependence," says Helen Pettinati, PhD, Research Professor in Penn's Department of Psychiatry, Director, Treatment Research Division in the Center for the Study of Addictions, and lead investigator for Penn's component of the trial.

"Long-acting naltrexone represents a promising new development for treatment, and I hope that it can play a role in helping the large number of individuals in the US who suffer from alcohol dependence," Dr. Pettinati said.

Burden of Daily Pill Taking Eliminated

Naltrexone was approved in pill form by the US Food and Drug Administration in 1994 for treating alcohol dependence. It 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 would have to take daily.

"Alcoholism is a serious disease that destroys lives. As we learn more about how the brain is affected by alcohol, we are discovering how best to provide treatment -- like adding a safe medication to counseling. A long-acting injectable, which eliminates the burden of daily pill taking, will open new doors for our patients and give hope to them and their families," adds Dr. Pettinati.

Lasting Progress Begins in First Week

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. In addition to an 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 was conducted at 24 sites nationwide, including public and private hospitals, Veterans Administration clinics and tertiary-care medical centers.

Other study authors included researchers from the medical schools at the University of Connecticut, Yale University, and Harvard University, and from Cambridge, Massachusetts-based Alkermes Incorporated, a biotechnology company that manufactures the long-acting naltrexone formulation (Vivitrex) used in the study.