RT Journal Article SR Electronic T1 DISPOSITION OF NALOXONE-7,8-3H IN NORMAL AND NARCOTIC-DEPENDENT MEN JF Journal of Pharmacology and Experimental Therapeutics JO J Pharmacol Exp Ther FD American Society for Pharmacology and Experimental Therapeutics SP 575 OP 580 VO 187 IS 3 A1 Jack Fishman A1 Howard Roffwarg A1 Leon Hellman YR 1973 UL http://jpet.aspetjournals.org/content/187/3/575.abstract AB Naloxone-7,8-3H was administered intravenously and orally on separate occasions to the same normal male subject and its disposition was examined. The fate of intravenous naloxone-7,8-3H was also studied in an opiate-dependent subject both while on heroin maintenance and after withdrawal. In all cases the urinary excretioon was rapid but incomplete, nerve exceeding 70% of the dose over 72 hours. Initial plasma concentrations of naloxone were low with a rapid rate of disappearance. Oral naloxone entered plasma quickly but in metabolized form. The volume of distribution, plasma half-life and metabolic clearance rate of naloxone as calculated from the intravenous studies were about 200 liters, 90 minutes and 2500 liters/day, respectively. © 1973 by The Williams & Wilkins Co.