RT Journal Article SR Electronic T1 NARCOTIC-ANTAGONIST ANALGESICS: INTERACTIONS WITH CHOLINERGIC SYSTEMS JF Journal of Pharmacology and Experimental Therapeutics JO J Pharmacol Exp Ther FD American Society for Pharmacology and Experimental Therapeutics SP 17 OP 22 VO 169 IS 1 A1 LOUIS S. HARRIS A1 WILLIAM L. DEWEY A1 JOHN F. HOWES A1 JAMES S. KENNEDY A1 HARRY PARS YR 1969 UL http://jpet.aspetjournals.org/content/169/1/17.abstract AB It has been found that the previously inactive narcoticantagonist analgesics become active in the mouse tail-flick test in the presence of physostigmine. Physostigmine itself and the centrally acting cholinergic agent oxotremorine are potent inhibitors of this reflex. Naloxone, a pure narcotic antagonist, can block the effects of physostigmine and oxotremorine. The narcotic-antagonist analgesics also block the contractions of the isolated coaxially stimulated guinea-pig ileum. In a wide variety of narcotic antagonists, a high correlation has been found between the activity of these compounds in this test procedure and their potency as analgesics in man. These results are discussed in support of the hypothesis that cholinergic systems may be involved in the analgesic action of these drugs. © 1969, by The Williams & Wilkins Company