title: History and development of mixed opioid agonists, partial agonists and antagonists.
abstract: 1 A brief history of the development of narcotic antagonists is outlined. 2 The clinical and pharmacological observations leading to the discovery of dualism of opiate receptors are reviewed. 3 An extension of this theory to a three-receptor model (mu, kappa and sigma) is required to rationalize the pharmacology of the antagonists analgesics cyclazocine, pentazocine and nalorphine. 4 The methodologies available for the study of compounds with dual agonist-antagonist activity are discussed in the light of the above receptor multiplicity, and data appertaining to the kappa-partial agonist, nalorphine and the mu-partial agonist buprenorphine are outlined.
mesh_terms: D000818:Animals; D004285:Dogs; D049673:History, 20th Century; D006801:Humans; D009020:Morphine / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000266:history* / Q000494:pharmacology; D009294:Narcotics / Q000266:history* / Q000494:pharmacology; D019966:Substance-Related Disorders
chemical_list: D009292:Narcotic Antagonists; D009294:Narcotics; D009020:Morphine