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Paracetamol. Andrew Dawson. Paracetamol: 2 Cases. A 16-year-old female (50 Kg): 2 hours following the ingestion of 10 grams of paracetamol. A 16-year-old female (50 Kg): 15 hours following the ingestion 12 grams of paracetamol. . 90% Conjugation. P450. Glutathione. NAPQI. NAPQI.
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Paracetamol Andrew Dawson
Paracetamol: 2 Cases • A 16-year-old female (50 Kg): 2 hours following the ingestion of 10 grams of paracetamol. • A 16-year-old female (50 Kg): 15 hours following the ingestion 12 grams of paracetamol.
90% Conjugation P450 Glutathione NAPQI NAPQI Paracetamol Toxicity
Conjugation Glucuronidation & Sulphation Paracetamol 85% P450 Toxic Metabolite Glutathione (SH) Non toxic metabolites Paracetamol • N-acetylcysteine • Methonine
Time to N-acetylcysteine (hours) and hepatotoxicity (%) Smilkstein MJ et al. Efficacy of oral N-acetylcysteine in the treatment of acetaminophen overdose: Analysis of the national multicenter study (1976 to 1985). N Engl J Med 1988; 319:1557-1562
Paracetamol • Risk of death is low • Risk of hepato-toxicity • >150 mgs/kg (conservative) • >200 mgs/kg • Blood level • Treatment is best if started within 8 hours • 15-20% patients early reaction to NAC (mild)
Paracetamol: 2 Cases • A 16-year-old female (50 Kg): 2 hours following the ingestion of 10 grams of paracetamol. • A 16-year-old female (50 Kg): 15 hours following the ingestion 12 grams of paracetamol.