Pharmacogenetics of Alcohol: Treatment Implications

Not Applicable

Completed

Interventions: Drug: placebo medication + placebo alcohol
Drug: placebo medication + ethanol
Drug: dutasteride + placebo alcohol
Drug: dutasteride + ethanol

Brief Summary: This study will explore the hypothesis that effects of alcohol are in part mediated by increased production of neuroactive steroids, which interact with GABAA-receptors. We propose to study non-dependent drinkers using a 4-session within-subjects design in which alcohol / placebo is paired with dutasteride / placebo pretreatment. Dutasteride is a 5-alpha steroid reductase (5AR) inhibitor that limits the production of dihydrotestosterone and the 5a-reduced neuroactive steroids allopregnanolone, pregnanolone and 3a,5a-androstanediol.

Detailed Description: 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).

Recruitment & Eligibility

Inclusion Criteria

Main Study: Subjects will be healthy volunteers with or without parental history of alcoholism who are 21-45 years old and who have a BMI >18.5 and <32.5. Drinking history: All subjects must report at least one occasion in the prior month of drinking at least 3 drinks on a single day; additionally, LD subjects will be selected if they drink 1-3 drinks, 1-3 times per week (up to 5 drinks per week on average), with no more than one occasion in the past 2 months on which they drank >4 drinks. HD subjects will be selected if they report drinking at least 10 drinks per week, with at least one episode per week of heavy drinking.

Exclusion Criteria

Main Study: Subjects cannot have a current or past DSM-IV diagnosis of alcohol or drug dependence, current or past 24-months diagnosis of alcohol or drug abuse or another major psychiatric disorder, neurological illness, have had a hypersensitivity reaction to dutasteride, evidence of liver dysfunction, currently be using benzodiazepines, other psychotropic medications or medications that are known to influence steroid hormone levels or metabolism or modify the effects of alcohol. Nicotine-dependent subjects will be excluded to avoid the confounding effects of nicotine withdrawal during day-long laboratory sessions. Women are not allowed to participate. Subjects anticipating moving from the area during the period of their planned study participation will be excluded from study entry.

Arm && Interventions

Group	Intervention	Description
Placebo medication + placebo alcohol	placebo medication + placebo alcohol	-
Placebo Medication + 0.8 gr/kg Ethanol	placebo medication + ethanol	-
4 mg Dutasteride + Placebo Alcohol	dutasteride + placebo alcohol	-
4 mg Dutasteride + 0.8 gr/kg Ethanol	dutasteride + ethanol	-

Primary Outcome Measures

Name	Time	Method
Breath Alcohol	40 minutes after beginning drink	Breath Alcohol level
BAES Sedation Response, Average of 6 Time Points	40, 80, 120, 160, 210 and 240 minutes after start of drinking	Biphasic Alcohol Effects Scale (BAES) Sedation items - sum of subjective responses - 0(not at all)to 10 (extremely)- for 7 sedation related questions regarding effects of alcohol. Total BAES sedation subscale score 0-70 with higher numbers indicating greater sedative effects of alcohol. \[Martin, C. S., M. Earleywine, R. E. Musty, M. W. Perrine and R. M. Swift (1993a). Development and validation of the Biphasic Alcohol Effects Scale. Alcohol Clin Exp Res 17(1): 140-6.\]
BAES Stimulation Response, Average of 6 Time Points	40, 80, 120, 160, 210 and 240 minutes after start of drinking	Biphasic Alcohol Effects Scale (BAES)Simulation items - sum of subjective responses - 0(not at all)to 10 (extremely)- for 7 stimulation related questions regarding effects of alcohol. Total BAES stimulation subscale score 0-70 with higher numbers indicating greater stimulating effects of alcohol. \[Martin, C. S., M. Earleywine, R. E. Musty, M. W. Perrine and R. M. Swift (1993a). Development and validation of the Biphasic Alcohol Effects Scale. Alcohol Clin Exp Res 17(1): 140-6.\]

Secondary Outcome Measures

Name	Time	Method
Change in Serum 3a-androstanediol Glucuronide	Baseline (pre medication administration) and 2-4 days post-medication (alcohol session)	Ratio of serum 3a-androstanediol drawn prior to alcohol administration (2-4 days after medication administration) compared to the baseline level prior to medication dose. The pharmacologic effect of dutasteride was measured by assay of serum 5a-androstan-3a,17b-diol,17-glucuronide (aka 3a-androstanediol glucuronide) as a biochemical measure of 5a-reductase enzyme inhibition. 3a-androstanediol glucuronide is the primary metabolic excretion product of 3a,5a-androstane neuroactive steroids. The