ETHANOL INHIBITION OF HEPATIC-UPTAKE OF DL-[2-C-14] METHADONE IN THE RAT AND ITS CONSEQUENCE

Misuse of alcohol by methadone patients could be accounted for by a number of factors: (a) availability, (b) ability of alcohol to go undetected in most spot-check urine tests for other drugs that addicts may be taking, thus meeting treatment program requirements, (c) synergistic effects of ethanol and methadone at the site of the receptors, or (d) a potentiation of the pharmacological effects of methadone by an ethanol-induced alteration in the pharmacokinetics of methadone. The present investigation has addressed itself to the latter point. Since the biotransformation of methadone in rats closely resembles that in humans (3), the rat was chosen as an animal model to study the effect of a single oral dose of ethanol on concomitantly administered dl-[2-14C]methadone.