Paracetamol (Acetaminophen) Overdose

Also known as Acetaminophen overdose · Paracetamol poisoning · N-acetylcysteine · NAC · Rumack-Matthew nomogram · NAPQI · Hepatotoxicity · Acute liver failure · King's College Criteria · Centrilobular necrosis · Glutathione depletion · Modified-release paracetamol · Anaphylactoid reaction · Panadol Osteo · CYP2E1

Paracetamol (acetaminophen) overdose — the commonest overdose and a leading cause of the acute liver failure. The metabolism to the toxic NAPQI via the CYP2E1 and the detoxification by the glutathione; the depletion of the glutathione in the overdose and the centrilobular hepatocyte necrosis. The clinical course (the four phases). The Rumack-Matthew nomogram and the treatment line. The N-acetylcysteine (the NAC) — the antidote that replenishes the glutathione, its timing (the effective within 8 hours), and the rate-related anaphylactoid reactions. The King's College criteria for the liver transplant. The management of the staggered and the massive ingestion.

high15 referencesUpdated 17 Aug 202627 min readSource-verified · Sept 2026

Checked against its sources on 2 Sept 2026

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Overview & definition

Paracetamol (acetaminophen) overdose is the commonest overdose in the developed world and the leading single cause of acute liver failure. Most patients do well — but give N-acetylcysteine (NAC) within 8 hours of ingestion and hepatotoxicity is prevented almost entirely. That 8-hour window is the whole job: recognise the overdose, plot the level, treat early.^[1]

References15Show

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