title: Origin and history of antagonists.
mesh_terms: D049673:History, 20th Century; D006801:Humans; D007977:Levallorphan / Q000138:chemical synthesis; D008745:Methylation; D009019:Morphinans / Q000138:chemical synthesis; D009269:Nalorphine / Q000266:history / Q000494:pharmacology / Q000627:therapeutic use; D009292:Narcotic Antagonists / Q000138:chemical synthesis / Q000266:history*; D019966:Substance-Related Disorders / Q000188:drug therapy
chemical_list: D009019:Morphinans; D009292:Narcotic Antagonists; D007977:Levallorphan; D009269:Nalorphine