title: The effect of naltrexone on alcohol's stimulant properties and self-administration behavior in social drinkers: influence of gender and genotype.
abstract: BACKGROUND
  Few pharmacological treatments for alcohol dependence are available. Moreover, the best supported treatment, naltrexone hydrochloride, appears to work for only some.
  
  
  METHODS
  To investigate potential predictors of these differential responses, 40 social drinkers (20 women) were administered 6 days of treatment with naltrexone vs. placebo in a double-blind, counterbalanced, crossover design. At the end of each treatment period, participants received a single dose of their preferred alcoholic beverage followed by the opportunity to work for additional alcohol units using a progressive ratio (PR) breakpoint paradigm. All subjects but one were genotyped for the A118G polymorphism of the mu opioid receptor gene (OPRM1).
  
  
  RESULTS
  Naltrexone decreased the ethanol-induced 'euphoria' to a priming dose of alcohol in two subgroups: (i) in women, and (ii) in subjects with the A118G polymorphism of the mu opioid receptor gene (OPRM1). Naltrexone did not decrease motivation to work for additional alcoholic beverages on the PR task regardless of gender or genotype.
  
  
  CONCLUSIONS
  The results add to the evidence that naltrexone decreases positive subjective effects of alcohol, with preferential effects in distinct subgroups. Similar effects in heavier drinkers might decrease alcohol use.
authors.affiliation: Department of Neurology and Neurosurgery, McGill University, Montréal, QC, Canada.
authors.forename: Elaine
authors.initials: E
authors.lastname: Setiawan
authors.forename: Robert O
authors.initials: RO
authors.lastname: Pihl
authors.forename: Sylvia M L
authors.initials: SM
authors.lastname: Cox
authors.forename: Christina
authors.initials: C
authors.lastname: Gianoulakis
authors.forename: Roberta M
authors.initials: RM
authors.lastname: Palmour
authors.forename: Chawki
authors.initials: C
authors.lastname: Benkelfat
authors.forename: Marco
authors.initials: M
authors.lastname: Leyton
mesh_terms: D000293:Adolescent; D000328:Adult; D000428:Alcohol Drinking / Q000188:drug therapy* / Q000235:genetics* / Q000523:psychology; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D009271:Naltrexone / Q000494:pharmacology / Q000627:therapeutic use*; D017450:Receptors, Opioid, mu / Q000235:genetics / Q000378:metabolism; D012646:Self Administration; D012727:Sex Characteristics; D055815:Young Adult
chemical_list: C485764:OPRM1 protein, human; D017450:Receptors, Opioid, mu; D009271:Naltrexone