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Acetaminophen (Paracetamol) Toxicity Assessment (Original, 1975)

 

Input
 

Hours After Ingestion		Days Hours
Acetaminophen Level		mcg/mL mcmol/L mg/L mg/dL

 
Results
 
Important: Inputs must be complete to perform calculation.

 

 

     
 
Include literature references: Yes   No

 

 

Notes

• In this calculator, mcg is the abbreviation for micrograms.
• This calculator is based on data from Rumack and Matthew¹. Treatment threshold levels are calculated to be 25% lower than the toxic drug level.
• This calculator is only appropriate for patients who had a single ingestion of acetaminophen.
• Drug levels done before the 4 hour point may not represent the true peak of absorption.
• In this calculation, the Rumack nomogram is represented by the following equations:
  • Toxic Level = e^{(5.298317 - ((Hours_After_Ingestion - 4) * 0.1732868))}
  • Treatment Level = Toxic Level - (0.25 * Toxic Level)

 
Equations used
 

ToxLevel = e(5.298317-((HoursAfterIngestion-4)*0.1732868))

RxLevel = ToxLevel - (0.25 * ToxLevel)

 

 

References

1. Rumack BH, Matthew H. Acetaminophen poisoning and toxicity. Pediatrics. 1975 Jun;55(6):871-6. PubMed ID: 1134886
2. White SJ, Rumack BH. The acetaminophen toxicity equations: "solutions" for acetaminophen toxicity based on the Rumack-Matthew nomogram. Ann Emerg Med. 2005 May;45(5):563-4. PubMed ID: 15855961
3. Buckley NA, Whyte IM, O'Connell DL, et al. Activated charcoal reduces the need for N-acetylcysteine treatment after acetaminophen (paracetamol) overdose. J Toxicol Clin Toxicol. 1999;37(6):753-7. PubMed ID: 10584587
4. Vale JA, Proudfoot AT. Paracetamol (acetaminophen) poisoning. Lancet. 1995 Aug 26;346(8974):547-52. Review. PubMed ID: 7658783

 

Associated Medical Subject Headings [MeSH]
 

80 and over,   Acetaminophen,   Acetylcysteine,   Adolescent,   Adult,   Aged,   Agranulocytosis,   Analgesics,   Charcoal,   Combination,   Cysteamine,   Dose-Response Relationship,   Drug,   Drug Overdose,   Drug Therapy,   Drug-Induced Liver Injury,   Female,   Gastric Lavage,   Humans,   Hypoglycemia,   Kidney Papillary Necrosis,   Liver,   Male,   Methionine,   Middle Aged,   Necrosis,   Nomograms,   Non-Narcotic,   Pericarditis,   Poison Control Centers,   Poisoning,   Prognosis,   Skin Manifestations,   Substance-Related Disorders

 

Associated Logical Observation Identifiers Names and Codes [LOINC]
 

Parameter	LOINC's and Suggested Units
Acetaminophen Level	12442-0 : mcg/mL      22736-3 : mcmol/L      3298-7 : mcg/mL      14581-3 : mcmol/L

 
This material contains content from LOINC® (http://loinc.org). The LOINC table, LOINC codes, and LOINC panels and forms file are copyright © 1995-2014, Regenstrief Institute, Inc. and the Logical Observation Identifiers Names and Codes (LOINC) Committee and available at no cost under the license at http://loinc.org/terms-of-use.