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IV N-acetylcysteine dosing for acetaminophen overdose
Weight-based 21-hour three-bag IV acetylcysteine regimen.
IV N-acetylcysteine dosing for acetaminophen overdose
Body weight
Doses are capped at a weight of 100 kg per the standard protocol.
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When to use
- Calculating the classic 21-hour IV acetylcysteine regimen once treatment is indicated by the nomogram or clinical criteria.
- Treatment decisions still rely on the Rumack-Matthew nomogram and time since ingestion, not this calculator.
Formula
150 mg/kg loading dose, then 50 mg/kg over 4 h, then 100 mg/kg over 16 h (total 300 mg/kg over 21 h). Dosing weight capped at 100 kg.
Pearls and pitfalls
- NAC is nearly fully protective when started within 8 hours of ingestion.
- Newer two-bag protocols reduce anaphylactoid reactions but deliver the same total dose.