State of the art of paracetamol in acute pain therapy.
OBJECTIVE
This review highlights new insights into the mechanism of action of paracetamol (acetaminophen) and therapeutic schemes.


RESULTS
Paracetamol, a centrally acting inhibitor of cyclooxygenases, has weak peripheral effects recently demonstrated. Paracetamol is nevertheless devoid of side effects commonly observed with the use of nonsteroidal anti-inflammatory drugs. Paracetamol is available by the oral, rectal, and, more recently, intravenous routes of administration. Paracetamol efficacy is surgical procedure dependent. The analgesic efficacy of a 2-g starting dose of intravenous paracetamol is superior to the recommended dose of 1 g in terms of magnitude and duration of analgesic effect. The usual scheme of administration (1 g every 6 hours) has a less than 10-mg sparing effect on 24-hour morphine consumption and consequently does not significantly reduce morphine side effects. The combination of nonsteroidal anti-inflammatory drugs and paracetamol is more effective than paracetamol alone, but the benefit is unclear when compared with nonsteroidal anti-inflammatory drugs used alone.


CONCLUSIONS
Further studies are required to assess the opioid-sparing effect and complementary analgesic effect of new intravenous paracetamol therapeutic schemes.
Remy
Camille
C
Service d'Anesthésie--Réanimation, Hôpital Tenon, Paris, France.
Marret
Emmanuel
E
Bonnet
Francis
F
D000082:Acetaminophen / Q000494:pharmacology / Q000627:therapeutic use*; D000208:Acute Disease; D018712:Analgesics, Non-Narcotic / Q000494:pharmacology / Q000627:therapeutic use*; D000818:Animals; D002490:Central Nervous System / Q000187:drug effects / Q000378:metabolism; D002986:Clinical Trials as Topic; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology / Q000627:therapeutic use*; D004359:Drug Therapy, Combination; D006801:Humans; D010147:Pain Measurement; D010149:Postoperative Pain / Q000378:metabolism / Q000517:prevention & control*; D011453:Prostaglandins / Q000378:metabolism
D018712:Analgesics, Non-Narcotic; D016861:Cyclooxygenase Inhibitors; D011453:Prostaglandins; D000082:Acetaminophen