Acetaminophen toxicity - Revision history

Danbot: Strip excess bold

2026-03-22T09:29:24Z

Strip excess bold

Danbot: Major update: Rumack-Matthew nomogram use, IV/PO NAC protocols, 2-bag protocol, King College Criteria, when to stop NAC, NAPQI mechanism, risk factors, anaphylactoid management, references with PMIDs

2026-03-21T19:55:26Z

Major update: Rumack-Matthew nomogram use, IV/PO NAC protocols, 2-bag protocol, King College Criteria, when to stop NAC, NAPQI mechanism, risk factors, anaphylactoid management, references with PMIDs

Show changes

Danbot: Add MedicationDose SMW annotations (NAC IV, NAC PO, activated charcoal); dosing verified per toxicology guidelines

2026-03-20T16:26:10Z

Add MedicationDose SMW annotations (NAC IV, NAC PO, activated charcoal); dosing verified per toxicology guidelines

← Older revision		Revision as of 16:26, 20 March 2026
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	{{Pediatric NAC dosing}}		{{Pediatric NAC dosing}}


			<div style="display:none">
			<!-- SMW MedicationDose annotations for acetaminophen toxicity medications -->
			{{MedicationDose\|drug=N-Acetylcysteine\|dose=150 mg/kg IV in 100 mL D5W over 60 min (load), then 50 mg/kg in 250 mL D5W over 4h, then 100 mg/kg in 500 mL D5W over 16h\|route=IV\|context=Antidote (IV protocol, preferred)\|indication=Acetaminophen toxicity\|display=NAC (IV)\|notes=Almost 100% effective if given <8h post-ingestion; continue until LFTs improve}}
			{{MedicationDose\|drug=N-Acetylcysteine\|dose=140 mg/kg PO load, then 70 mg/kg PO q4h x17 additional doses\|route=PO\|context=Antidote (PO protocol)\|indication=Acetaminophen toxicity\|display=NAC (PO)\|notes=Less preferred due to unpleasant taste/smell; dilute to 5% solution}}
			{{MedicationDose\|drug=Activated charcoal\|dose=1 g/kg PO (if <3h post-ingestion)\|route=PO\|context=GI decontamination\|indication=Acetaminophen toxicity\|notes=No role for multidose activated charcoal}}
			</div>
	==Disposition==		==Disposition==
	*Consider discharge for asymptomatic patients who do not require NAC		*Consider discharge for asymptomatic patients who do not require NAC

Imogen: /* External Links */ add consensus statement

2025-08-16T04:44:10Z

External Links: add consensus statement

← Older revision		Revision as of 04:44, 16 August 2025
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	*[http://www.mdcalc.com/kings-college-criteria-for-acetaminophen-toxicity/ MDCalc - King's College Criteria for Acetaminophen Toxicity]		*[http://www.mdcalc.com/kings-college-criteria-for-acetaminophen-toxicity/ MDCalc - King's College Criteria for Acetaminophen Toxicity]
	*[https://www.merckmanuals.com/professional/injuries-poisoning/poisoning/acetaminophen-poisoning?query=acetaminophen%20poisoning\| Merk Manual: Acetaminophen Poisoning]		*[https://www.merckmanuals.com/professional/injuries-poisoning/poisoning/acetaminophen-poisoning?query=acetaminophen%20poisoning\| Merk Manual: Acetaminophen Poisoning]
			*[https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2808062 Management of Acetaminophen Poisoning in the US and Canada: A Consensus Statement (2023)]

	==References==		==References==

Rossdonaldson1: /* Video */

2024-04-17T20:08:54Z

Video

← Older revision		Revision as of 20:08, 17 April 2024
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	*[http://www.mdcalc.com/kings-college-criteria-for-acetaminophen-toxicity/ MDCalc - King's College Criteria for Acetaminophen Toxicity]		*[http://www.mdcalc.com/kings-college-criteria-for-acetaminophen-toxicity/ MDCalc - King's College Criteria for Acetaminophen Toxicity]
	*[https://www.merckmanuals.com/professional/injuries-poisoning/poisoning/acetaminophen-poisoning?query=acetaminophen%20poisoning\| Merk Manual: Acetaminophen Poisoning]		*[https://www.merckmanuals.com/professional/injuries-poisoning/poisoning/acetaminophen-poisoning?query=acetaminophen%20poisoning\| Merk Manual: Acetaminophen Poisoning]

	~~==Video==~~
	~~{{#widget:YouTube\|id=MO__A9k9w2I}}~~

	==References==		==References==

Blsimpso: /* Work-Up */

2021-07-15T01:12:27Z

Work-Up

← Older revision		Revision as of 01:12, 15 July 2021
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	*LFT		*LFT
	**AST and ALT elevation more specific than GGT and alkaline phosphatase		**AST and ALT elevation more specific than GGT and alkaline phosphatase
			**AST levels > 1000 IU/L are more likely to result from acetaminophen poisoning than from chronic hepatitis or alcoholic liver disease<ref>By, O’Malley GF, O’Malley R. Acetaminophen Poisoning - Injuries; Poisoning. Merck Manuals Professional Edition. https://www.merckmanuals.com/professional/injuries-poisoning/poisoning/acetaminophen-poisoning?query=acetaminophen+poisoning. Published April 2020. Accessed July 15, 2021.</ref>
	*PT/PTT/INR		*PT/PTT/INR
	*[[Aspirin]] levels and other co-ingestants		*[[Aspirin]] levels and other co-ingestants

Blsimpso: /* External Links */

2021-07-15T00:56:12Z

External Links

← Older revision		Revision as of 00:56, 15 July 2021
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	*[http://www.mdcalc.com/acetaminophen-overdose-and-iv-nac-dosing/ MDCalc - Acetaminophen Overdose & NAC Dosing]		*[http://www.mdcalc.com/acetaminophen-overdose-and-iv-nac-dosing/ MDCalc - Acetaminophen Overdose & NAC Dosing]
	*[http://www.mdcalc.com/kings-college-criteria-for-acetaminophen-toxicity/ MDCalc - King's College Criteria for Acetaminophen Toxicity]		*[http://www.mdcalc.com/kings-college-criteria-for-acetaminophen-toxicity/ MDCalc - King's College Criteria for Acetaminophen Toxicity]
			*[https://www.merckmanuals.com/professional/injuries-poisoning/poisoning/acetaminophen-poisoning?query=acetaminophen%20poisoning\| Merk Manual: Acetaminophen Poisoning]

	==Video==		==Video==

Kxl328: /* Work-Up */

2020-07-30T18:46:41Z

Work-Up

← Older revision		Revision as of 18:46, 30 July 2020
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	*Chemistry		*Chemistry
	**[[Metabolic acidosis]] seen with extremely large ingestion		**[[Metabolic acidosis]] seen with extremely large ingestion
			**Lactic acid and blood gas<ref>Zein JG, Wallace DJ, Kinasewitz G, Toubia N, Kakoulas C. Early anion gap metabolic acidosis in acetaminophen overdose. Am J Emerg Med. 2010;28:798-802.</ref>
	*LFT		*LFT
	**AST and ALT elevation more specific than GGT and alkaline phosphatase		**AST and ALT elevation more specific than GGT and alkaline phosphatase

Rossdonaldson1: /* Background */

2020-06-04T18:01:30Z

Background

← Older revision		Revision as of 18:01, 4 June 2020
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	*Includes Tylenol and numerous brands and products including [[acetaminophen]]		*Includes Tylenol and numerous brands and products including [[acetaminophen]]
	*Now the most common cause of acute liver failure in the US<ref>Ostapowicz G, Fontana RJ, Schiodt FV, et al. Results of a prospective study of acute liver failure at 17 tertiary care centers in the United States. Ann Intern Med. 2002 Dec 17; 137(12): 947-54.</ref>		*Now the most common cause of acute liver failure in the US<ref>Ostapowicz G, Fontana RJ, Schiodt FV, et al. Results of a prospective study of acute liver failure at 17 tertiary care centers in the United States. Ann Intern Med. 2002 Dec 17; 137(12): 947-54.</ref>
	*Small amount of [[acetaminophen]] is metabolized by Cytochrome[[P450]] into NAPQI, which is a toxic metabolite
	*In therapeutic doses, NAPQI combines rapidly with glutathione to form nontoxic metabolites that are excreted in the urine
	*In overdose, glutathione stores are used up and NAPQI binds to cell proteins in the liver which leads to cell death

	===Maximal acetaminophen daily doses===		===Maximal acetaminophen daily doses===

Rossdonaldson1 at 18:00, 4 June 2020

2020-06-04T18:00:58Z

← Older revision		Revision as of 18:00, 4 June 2020
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	==Background==		==Background==
	*Includes Tylenol and numerous brands and products including [[acetaminophen]]		*Includes Tylenol and numerous brands and products including [[acetaminophen]]
			*Now the most common cause of acute liver failure in the US<ref>Ostapowicz G, Fontana RJ, Schiodt FV, et al. Results of a prospective study of acute liver failure at 17 tertiary care centers in the United States. Ann Intern Med. 2002 Dec 17; 137(12): 947-54.</ref>
			*Small amount of [[acetaminophen]] is metabolized by Cytochrome[[P450]] into NAPQI, which is a toxic metabolite
			*In therapeutic doses, NAPQI combines rapidly with glutathione to form nontoxic metabolites that are excreted in the urine
			*In overdose, glutathione stores are used up and NAPQI binds to cell proteins in the liver which leads to cell death

	===Maximal acetaminophen daily doses===		===Maximal acetaminophen daily doses===