6-beta-naltrexol reduces alcohol consumption in rats

Background: In humans, 6-beta-naltrexol is the major metabolite of naltrexo ne, and its effectiveness at suppressing alcohol consumption in any species has not been previously investigated. Naltrexone is an opiate antagonist t hat reduces excessive drinking in many species, including humans with alcoh ol dependence. Whether 6-beta-naltrexol is an active metabolite that contri butes to the efficacy of naltrexone remains unknown. Methods: Placebo and four doses of 6-beta-naltrexol were given by intraperi toneal injection to outbred Wistar rats and alcohol consumption was measure d using a limited access model. Results: 6-beta-Naltrexol reduced alcohol consumption in a dose-dependent m anner. At doses 7.5, 12.5, and 25 mg/kg, 6-beta-naltrexol significantly dec reased consumption of a 6% ethanol solution compared with saline control gr oups. Conclusions: These data suggest that there may be a potential clinical use for 6-beta-naltrexol in recovering alcoholics.