Role of caffeine in combined analgesic drugs from the point of view of experimental pharmacology.
The interactions of caffeine (CAS 58-08-2) with acetylsalicylic acid (CAS 50-78-2, ASA) and paracetamol (CAS 103-90-2) were investigated with regard to the analgesic, antiphlogistic, antipyretic and other properties. The inhibitory effect of paracetamol and ASA on the prostaglandin biosynthesis in a cyclooxygenase preparation from bovine brain in vitro was not affected by the addition of caffeine. Caffeine additively increases the antinociceptive effect of paracetamol with regard to the heat-induced pain in the mouse, as does aminophenazone. The antinociceptive effect of aminophenazone on the mechanically induced pain in the mouse is also additively increased by caffeine. In contrast to the effect of aminophenazone on the inflammatory pain in the rat, the effect of ASA is not increased by caffeine and that of paracetamol only negligibly. The antipyretic effect of paracetamol is additively increased by caffeine in the normothermic rat. The antipyretic effect of ASA and paracetamol on the yeast-induced pyrexia of the rat is not affected by caffeine. Caffeine additively increases the acute antiexudative effect of ASA and aminophenazone on the carageenin-induced oedema of the hind paw of the rat. The increase in locomotor activity caused by caffeine in mouse and rat is neutralised or diminished when the caffeine is given in combination with paracetamol. This effect is maintained even if the rats are pretreated with the combination of active ingredients for 3 weeks. The ulcerogenic effect of ASA in the stomach of the rat is not increased by caffeine. The protective effect of ASA against the hepatotoxic effect of paracetamol in the mouse is not influenced by the addition of caffeine. The plasma levels after the oral administration of 20 mg/caffeine/ kg and 80 mg paracetamol/kg in the rat are not significantly changed when the substances are given in combination. The toxicological advantages resulting from combining ASA and paracetamol with caffeine are discussed.
Engelhardt
G
G
Department of Biological Research, Boehringer Ingelheim, Biberach/Riss, Germany.
Mauz
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AB
Pairet
M
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D000082:Acetaminophen / Q000494:pharmacology / Q000633:toxicity; D018712:Analgesics, Non-Narcotic / Q000494:pharmacology* / Q000633:toxicity; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D001241:Aspirin / Q000494:pharmacology / Q000633:toxicity; D001923:Brain Chemistry / Q000187:drug effects; D002110:Caffeine / Q000494:pharmacology* / Q000633:toxicity; D002417:Cattle; D000697:Central Nervous System Stimulants / Q000494:pharmacology* / Q000633:toxicity; D004338:Drug Combinations; D004558:Electric Stimulation; D004798:Enzymes / Q000097:blood; D066298:In Vitro Techniques; D007249:Inflammation / Q000473:pathology / Q000523:psychology; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D008815:Mice, Inbred Strains; D009043:Motor Activity / Q000187:drug effects; D010147:Pain Measurement / Q000187:drug effects; D010812:Physical Stimulation; D011453:Prostaglandins / Q000096:biosynthesis; D051381:Rats; D011919:Rats, Inbred Strains; D013276:Stomach Ulcer / Q000139:chemically induced / Q000473:pathology
D018712:Analgesics, Non-Narcotic; D000894:Anti-Inflammatory Agents, Non-Steroidal; D000697:Central Nervous System Stimulants; D004338:Drug Combinations; D004798:Enzymes; D011453:Prostaglandins; D000082:Acetaminophen; D002110:Caffeine; D001241:Aspirin