N-Acetylcysteine (NAC)
Acetaminophen overdose, Acute liver failure from acetaminophen
Indications
- Acetaminophen overdose
- Acute liver failure from acetaminophen
Adult dosing
- iv protocol: dose: 150; unit: mg/kg IV over 1h, then 50mg/kg over 4h, then 100mg/kg over 16h; route: IV; weightBased: true; maxDose: 15000; maxDoseAbsolute: true; oral 72h: dose: 140; unit: mg/kg loading, then 70mg/kg q4h x 17 doses; route: PO; weightBased: true; maxDose: 15000; maxDoseAbsolute: true
Pediatric dosing
- iv protocol: dose: 150; unit: mg/kg IV over 1h, then 50mg/kg over 4h, then 100mg/kg over 16h; route: IV; weightBased: true; maxDose: 15000; maxDoseAbsolute: true
Clinical pearls
- Most effective within 8 hours of ingestion but beneficial up to 24+ hours
- Use Rumack-Matthew nomogram to determine need — plot APAP level at 4+ hours post-ingestion
- Anaphylactoid reactions common with IV (10-20%) — slow infusion rate, give antihistamines
- Modified Prescott (2-bag) protocol gaining popularity: 200mg/kg over 4h then 100mg/kg over 16h
Source and review
- Goldfrank's Toxicologic Emergencies; ACT recommendations. Last reviewed: 2024-11-01