Clinical Trial of the Cannabinoid CB1 Receptor Antagonist, SR141716 (Rimonabant), to Reduce Voluntary Ethanol Drinking in Healthy, Non-Treatment Seeking Individuals Who Consume Between 20 and 50 Drinks Per Week

This study will examine whether Rimonabant, a drug that blocks cannabinoid-1 (CB1) receptors in the brain, affects alcohol consumption. Substances called endocannabinoids, which have many of the same effects of marijuana, bind to CB1 receptors. Animal studies show that when CB1 receptors are blocked, the animals consume less alcohol. Healthy normal volunteers between 21 and 40 years of age who consume between 20 and 40 alcoholic drinks per week, drink at least 4 days a week, and are not seeking treatment for alcoholism may be eligible for this study. Candidates are screened with a medical history, including questions about alcohol and drug use, physical examination, blood and urine tests, breath alcohol test, and electrocardiogram. Participants are asked about their mental health history and use of alcohol, cigarettes and illicit drugs, and fill out questionnaires evaluating their emotional state and personality. Then, they begin a baseline evaluation in which they call a number at the NIH Clinical Center for 21 days to report how much alcohol they drank that day. One week after starting the baseline evaluation, they are randomly assigned to take either Rimonabant or placebo (a pill with no active ingredient) for 2 weeks. Before starting the drug, they have a urine drug screen and measurement of blood alcohol level. After 1 week on the test medication, they return to the Clinical Center to monitor drug or placebo side effects, if any, and to have a blood alcohol level test, urine drug screen, and blood tests for routine blood chemistries. After 2 weeks on the test medication, they come to the Clinical Center at noon for an alcohol self-administration test. Before the test, they are given a breath alcohol test and a urine drug test. The results of both tests must be negative to continue in the study. The alcohol self-administration test is videotaped. A heparin lock is placed in a vein in the participant's arm. This small needle remains in the arm for the duration of the study to avoid multiple needle sticks for blood draws. Blood is drawn periodically during the test to determine routine laboratory values, cotinine level (assessment of smoking status), the amount of Rimonabant or placebo in the body, and levels of various hormones. Thirty minutes before the test begins and every 30 minutes during the test, participants complete questionnaires and rating scales regarding their mood and desire to drink. Five minutes before the test be...