The dose-related effects of paracetamol on hyperalgesia and nociception in the rat.
1. We have studied the effects of 3 low doses of paracetamol (25, 50 and 100 mg kg-1 p.o.) on inflammatory hyperalgesia, inflammatory oedema, and nociceptive thresholds in rats. 2. At the lower dose (25 mg kg-1), paracetamol reduces only central hyperalgesia. 3. At the doses of 50 and 100 mg kg-1, paracetamol reduces also peripheral hyperalgesia; moreover, it enhances nociceptive thresholds to a mechanical stimulus in the non-inflamed paws. 4. Neither paw inflammatory oedema nor tail nociceptive thresholds to a thermal stimulus were modified by paracetamol administration. 5. Our results suggest that paracetamol can reduce hyperalgesia without affecting physiological nociception and inflammation.
Bianchi
M
M
Department of Pharmacology, University of Milano, Italy.
Panerai
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AE
D000082:Acetaminophen / Q000494:pharmacology*; D018712:Analgesics, Non-Narcotic / Q000494:pharmacology*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D006614:Hindlimb; D007249:Inflammation / Q000209:etiology / Q000503:physiopathology*; D008297:Male; D009183:Mycotoxins; D010147:Pain Measurement / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012441:Saccharomyces cerevisiae; D013623:Tail
D018712:Analgesics, Non-Narcotic; D009183:Mycotoxins; D000082:Acetaminophen