Acetaminophen Overdose

 

Substance

-          Acetaminophen

 

Common name or Trade name

-          普拿疼

-          Paracetamol.

Involving system

-          Hepatic toxicity. [1]

 

Presentation  [1]

-          GI upset in initial 24 hours, nausea, anorexia, malaise、looking pale、sweating.

-          2 to 3^rd day: elevated GOT and GPT; RUQ abdominal pain, decrement of urine amount.

-          3^rd to 4^th day: hepatocellular damage, abdominal pain, jaundice, coagulopathy, hepatic encephalopathy or coma. Lethal possibility.

-          4^th day to 3^rd week resolution of hepatic function.  

-          Rumack-Matthew Nomogram to estimate the toxicity severity [2].

Antidote and Treatment [1]

-          GI decontamination

-          Activated charcoal and laxative agent

-          N-acetylcysteine (NAC) oral 140 mg/ kg, every 4 hours 70 mg / kg * 17 doses.

-          If nausea, vomiting，change into IV form，and treated for 48 hours.  

-         Mechanism: reduce NAPQI damage to hepatic cell. Needs to administrate within 8 hours, if not, hepatoxicity was 5.5-fold higher for cases [3]

-         IV formula: intravenous loading regimen: 150 mg/kg over 15 min, followed by 50 mg/kg over 4 h, and then 100 mg/kg over 16 h [4].

-           

Disposition [1]

-          Poor outcome when ABG PH< 7.3, PT > 100 seconds, creatinine > 3.3mg/dL, Gr. III to IV hepatic encephalopathy.

-          Admit to ICU when hemodynamic unstable, shortness of breath, coma, acute kidney failure, massive GI bleeding. Severe acidosis.  

-          If hepatic failure, needs hepatic transplantation.  

 

References

[1] 乙醯氨酚服用過量 台灣醫界 49(9).

 

[2]. Seifert SA, Kirschner RI, Martin TG, Schrader RM, Karowski K, Anaradian PC. Acetaminophen concentrations prior to 4 hours of ingestion: impact on diagnostic decision-making and treatment. Clin Toxicol (Phila). 2015;53(7):618-23. doi: 10.3109/15563650.2015.1059942. Epub 2015 Jun 24. PMID: 26107627.

 

[3] Downs JW, Cumpston KL, Kershner EK, Troendle MM, Rose SR, Wills BK. Clinical outcome of massive acetaminophen overdose treated with standard-dose N-acetylcysteine. Clin Toxicol (Phila). 2021 Feb 23:1-8. doi: 10.1080/15563650.2021.1887493. Epub ahead of print. PMID: 33620007.

 

[4]. Waring WS. Novel acetylcysteine regimens for treatment of paracetamol overdose. Ther Adv Drug Saf. 2012 Dec;3(6):305-15. doi: 10.1177/2042098612464265. PMID: 25083244; PMCID: PMC4110842.

edited by Yu-Jang Su   May 16, 2021