title: Failure of coffee to inhibit the pharmacodynamic activity of morphine in vivo.
abstract: High doses of caffeine-containing as well as decaffeinated instant coffee neither inhibited morphine-induced analgesia in mice nor the morphine-induced fall of blood pressure, heart rate and respiratory rate in rats. On the contrary, caffeine-containing coffee even enhanced the analgesic effects of morphine in mice. Coffee thus does not exhibit opiate-antagonizing activity in the whole organism in vivo. The very weak morphine-antagonistic efficacy of coffee powder in the myenteric plexus-longitudinal muscle preparation from the guinea pig ileum is of no practical importance.
mesh_terms: D000698:Analgesia; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002110:Caffeine / Q000494:pharmacology*; D003069:Coffee; D006168:Guinea Pigs; D006339:Heart Rate / Q000187:drug effects; D008297:Male; D051379:Mice; D009020:Morphine / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D009130:Muscle, Smooth / Q000187:drug effects; D009270:Naloxone / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D012119:Respiration / Q000187:drug effects
chemical_list: D003069:Coffee; D009270:Naloxone; D002110:Caffeine; D009020:Morphine