title: Naloxone-morphine synergism: support for dual system hypothesis of pain perception.
mesh_terms: D000698:Analgesia; D004357:Drug Synergism; D006801:Humans; D009020:Morphine / Q000494:pharmacology*; D009270:Naloxone / Q000494:pharmacology*; D010146:Pain / Q000503:physiopathology*
chemical_list: D009270:Naloxone; D009020:Morphine