EFFECTS OF OPIOIDS ON THE ABSORPTION OF ALCOHOL

Administration of opiate agonists and antagonists has been shown to in crease and decrease alcohol consumption, respectively. Because opioids can affect gastric emptying and decrease intestinal motility, the pre sent experiments were done to determine whether changes in alcohol con sumption following opioid administration might be due to opioid-induce d changes in the pharmacokinetics of alcohol. rn experiment 1, morphin e in doses ranging from 1.5 to 4.5 mg/kg dose dependently decreased th e absorption of alcohol induced by oral intubation (I g/kg) and reduce d peak blood alcohol levels (BALs). Naltrexone in doses ranging from 1 .5 to 4.5 mg/kg produced a small, but significant, reduction in the ab sorption of alcohol, but the effects were not dose related. Similar ef fects of morphine and naltrexone on alcohol absorption were observed i n rats infused with alcohol (1 g/kg) through an implanted intragastric cannula. The effects of morphine on alcohol absorption were observed whether alcohol levels were determined from tail vein or arterial bloo d samples or from brain samples. The effects of morphine on alcohol ab sorption were not blocked by pretreatment with methyl-naltrexone. Howe ver, the peripherally acting opioid agonist loperamide reduced BALs in a manner similar to morphine. These studies indicate that although op iate agonists and antagonists modify alcohol absorption to different e xtents, their effects on BALs are not a sufficient condition to induce changes in alcohol consumption. (C) 1997 Elsevier Science Inc.