Educational Pearls:

• Acetaminophen overdose can also present in patients taking too much over the course of days to weeks - not just intentional ingestions
• If acute overdose is suspected, refer to the Rumak-Matthew nomogram to guide treatment based on time of ingestion and the time of level
• In chronic overdose, Tylenol levels will not guide treatment
• NAPQI is the toxic metabolite of acetaminophen
• N-acetylcysteine (NAC) can be effective treatment in both acute and chronic overdoses
• 7.5 g is the daily toxic dose of Tylenol in adults, 150mg/kg in children

References:

Smilkstein MJ. Acetaminophen. In: Goldfrank's Toxicologic Emergencies, Goldfrank LR, Flomenbaum NE, Lewin NA, et al (Eds), Appleton & Lange, Stamford 1998. P.541.

Chiew AL, Gluud C, Brok J, Buckley NA. Interventions for paracetamol (acetaminophen) overdose. Cochrane Database Syst Rev. 2018 Feb 23;2:CD003328. doi: 10.1002/14651858.CD003328.pub3. Review. PubMed PMID: 29473717.

Lancaster EM, Hiatt JR, Zarrinpar A. Acetaminophen hepatotoxicity: an updated review. Arch Toxicol. 2015 Feb;89(2):193-9. doi: 10.1007/s00204-014-1432-2. Epub 2014 Dec 24. Review. PubMed PMID: 25537186.

Summarized by Will Dewispelaere, MS3 | Edited by Erik Verzemnieks, MD