Pharmacogenetics of Alcohol: Treatment Implications

Alcohol has multiple pharmacological effects, though which of these effects relate to the risk of alcohol dependence is not clear. Animal studies indicate that the neuroactive steroid allopregnanolone is an alcohol-modulated endogenous agonist at GABAA receptors and that genetic variation in steroid 5a-reductase type I gene which generates neuroactive steroids, may moderate alcohol effects. To better define the role of neuroactive steroids we will conduct a laboratory study of non-alcohol dependent drinkers using a 4-session design in which alcohol/placebo beverage is paired with dutasteride/placebo pretreatment. Dutasteride, an inhibitor of both type I and type II 5a-reductase enzymes, blocks the production of 5a-reduced neuroactive steroids. This study will extend our preliminary findings with finasteride by including a) a placebo control for alcohol, b) a more specific inhibitor of both 5a-reductase isoenzymes, c) a larger group of subjects (including both light and heavy drinkers).