Long-acting injections of the drug Naltrexone, combined with psychotherapy, significantly reduced heavy drinking in patients being treated for alcohol dependence.


Oral naltrexone is effective in treating alcohol and opiate dependencies, but poor patient adherence and widely fluctuating plasma levels limit its efficacy.

To overcome these problems, an extended-release formulation of Naltrexone ( Vivitrex ) was developed by encapsulating Naltrexone into injectable, biodegradable polymer microspheres.

Acohol dependence ranks as the fourth leading cause of disability worldwide, as reported by the World Health Organization's Global Burden of Disease project.
In the U.S., approximately 18 million people are dependent on or abuse alcohol and an estimated 2.3 million adults seek treatment each year . Even among individuals currently seeking treatment, the majority relapse . Alcohol is causally related to more than 60 medical conditions, including heart disease, liver disease, infectious disease, and cancer, and contributes to more than 100,000 deaths in the U.S. each year.

A Phase III multicenter, double-blind, placebo-controlled clinical trial, led by James C. Garbutt, M.D., Professor of Psychiatry at University of North Carolina at Chapel Hill, included 624 patients, more than 90% of whom were actively drinking at study enrollment.
Patients were randomized to receive either Vivitrex 380 mg (n = 205), Vivitrex 190 mg (n = 210), or a placebo (n = 209) administered by injection in a clinical setting once per month for six months. All patients received standardized, low-intensity counseling consisting of 12 sessions during the six-month study.

The primary endpoint of the study was the reduction in the event rate of heavy drinking days. Heavy drinking is defined as five or more drinks per day for men and four or more drinks per day for women. Of the various measures of drinking behavior, heavy drinking shows the highest correlation with negative life consequences such as impaired driving, interpersonal problems and injuries .

In the overall study population, Vivitrex was associated with a statistically significant reduction in the rate of heavy drinking relative to placebo (p = 0.0245). Additional highlights for the Vivitrex 380 mg treatment group include:

- The median number of heavy drinking days was reduced from 19 days per month in the month prior to the study to three days per month over the six months of Vivitrex treatment.

- Vivitrex 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.

- Adverse events were predominantly mild and decreased over time. The three most common adverse events reported were: nausea, headache and fatigue.

- Injection site reactions were more commonly seen in the treatment groups versus the placebo group. Approximately 1% of subjects discontinued participation in the trial due to injection site reaction.

Source: Journal of American Medical Association, 2005


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