Selective attenuation of ethanol-induced performance impairment by naloxone in humans

Healthy human subjects performed a vigilance task involving decision making and motor responses under four drug conditions involving random assignment and double blind procedures. Naloxone (0.4 mg) or saline was injected intravenously before subjects consumed a drink of alcohol (0.56 gm ethanol per kg body weight) or a simulated alcoholic drink. Blood alcohol concentrations averaged 60 mg/dl. The impaired performance of the task by this blood alcohol concentration was ameliorated by prior administration of naloxone at one testing point in the study sequence (40 minutes after ingesting the alcohol). The effect was associated with a history of light drinking (mean intake 0.93 gm/kg of body weight/month). Further studies to characterize this phenomenon more fully are proposed.