Last update:
12-Jul-2004

Paracetamol (acetaminophen) is the most widely used analgesic in the world and is one of the most frequent causes of poisoning due to pharmaceutical agents. The primary clinical effect of paracetamol poisoning is hepatotoxicity which occurs through accumulation of the toxic intermediate metabolite N-acetyl-p-benzoquinoneimine (NAPQI) when hepatic glutathione stores are depleted. N-acetylcysteine (NAC) is the treatment of choice for paracetamol poisoning and it is most effective when administered during the first 8 hours. However, late administration (15 hours after paracetamol overdose) has now been shown to be safe, while beneficial results may be obtained up to and possibly beyond 24 hours. Furthermore, administration of NAC to patients who have already developed fulminant hepatic failure has been shown to reduce morbidity and mortality. Adverse effects have been reported in a small proportion of patients after NAC administration, many of which are dose dependent. There is no evidence that either paracetamol or NAC are teratogenic when administered in pregnancy.

Key words: N-acetylcysteine, Paracetamol intoxication, Paracetamol poisoning.