Paracetamol poisoning

For the tampering of Tylenol bottles in 1982, see Chicago Tylenol murders.

Paracetamol poisoning
Other namesAcetaminophen toxicity, paracetamol toxicity, acetaminophen poisoning, paracetamol overdose, acetaminophen overdose, Tylenol toxicity
Paracetamol
SpecialtyToxicology
SymptomsEarly: Non specific, feeling tired, abdominal pain, nausea
Later: Yellowish skin, blood clotting problems, confusion
ComplicationsLiver failure, kidney failure, pancreatitis, low blood sugar, lactic acidosis.
Usual onsetAfter 24 hours (toxicity)[1]
CausesParacetamol (acetaminophen) usually > 7 g[2][1]
Risk factorsAlcoholism, malnutrition, certain other hepatotoxic medications[1]
Diagnostic methodBlood levels at specific times following use[1]
Differential diagnosisAlcoholism, viral hepatitis, gastroenteritis[1]
TreatmentActivated charcoal, acetylcysteine, liver transplant[1]
PrognosisDeath occurs in ~0.1%[1]
Frequency>100,000 per year (US)[1]

Paracetamol poisoning, also known as acetaminophen poisoning, is caused by excessive use of the medication paracetamol (acetaminophen).[2] Most people have few or non-specific symptoms in the first 24 hours following overdose. These symptoms include feeling tired, abdominal pain, or nausea. This is typically followed by absence of symptoms for a couple of days, after which yellowish skin, blood clotting problems, and confusion occurs as a result of liver failure. Additional complications may include kidney failure, pancreatitis, low blood sugar, and lactic acidosis. If death does not occur, people tend to recover fully over a couple of weeks.[3][4] Without treatment, death from toxicity occurs 4 to 18 days later.[5]

Paracetamol poisoning can occur accidentally or as an attempt to die by suicide. Risk factors for toxicity include alcoholism, malnutrition, and the taking of certain other hepatotoxic medications.[1] Liver damage results not from paracetamol itself, but from one of its metabolites, N-acetyl-p-benzoquinone imine (NAPQI).[6] NAPQI decreases the liver's glutathione and directly damages cells in the liver.[7] Diagnosis is based on the blood level of paracetamol at specific times after the medication was taken.[1] These values are often plotted on the Rumack-Matthew nomogram to determine level of concern.[1]

Treatment may include activated charcoal if the person seeks medical help soon after the overdose.[1] Attempting to force the person to vomit is not recommended.[6] If there is a potential for toxicity, the antidote acetylcysteine is recommended.[1] The medication is generally given for at least 24 hours.[6] Psychiatric care may be required following recovery.[1] A liver transplant may be required if damage to the liver becomes severe. The need for transplant is often based on low blood pH, high blood lactate, poor blood clotting, or significant hepatic encephalopathy. With early treatment liver failure is rare.[6] Death occurs in about 0.1% of cases.[1]

Paracetamol poisoning was first described in the 1960s.[6] Rates of poisoning vary significantly between regions of the world.[8] In the United States more than 100,000 cases occur a year.[1] In the United Kingdom it is the medication responsible for the greatest number of overdoses.[7] Young children are most commonly affected.[1] In the United States and the United Kingdom, paracetamol is the most common cause of acute liver failure.[9][1]

  1. ^ a b c d e f g h i j k l m n o p q r Ferri FF (2016). Ferri's Clinical Advisor 2017 E-Book: 5 Books in 1. Elsevier Health Sciences. p. 11. ISBN 978-0-323-44838-3. Archived from the original on September 10, 2017. Retrieved July 6, 2017.
  2. ^ a b Woolley D, Woolley A (2017). Practical Toxicology: Evaluation, Prediction, and Risk, Third Edition. CRC Press. p. 330. ISBN 978-1-4987-0930-9. Archived from the original on September 10, 2017. Retrieved July 5, 2017.
  3. ^ Proudfoot AT, Wright N (September 5, 1970). "Acute Paracetamol Poisoning". BMJ. 3 (5722): 557–558. doi:10.1136/bmj.3.5722.557. PMC 1701561. PMID 5311516.
  4. ^ Ferner RE, Dear JW, Bateman DN (April 19, 2011). "Management of paracetamol poisoning". BMJ. 342 (apr19 2): d2218. doi:10.1136/bmj.d2218. PMID 21508044. S2CID 5339635.
  5. ^ Chun L.J., Tong M.J., Busuttil R.W., Hiatt J.R. Acetaminophen hepatotoxicity and acute liver failure. J Clin Gastroenterol. 2009;43:342–349.
  6. ^ a b c d e Webb A, Gattinoni L (2016). Oxford Textbook of Critical Care. Oxford University Press. p. 1518. ISBN 978-0-19-960083-0. Archived from the original on September 10, 2017. Retrieved July 6, 2017.
  7. ^ a b Prout J, Jones T, Martin D (2014). Advanced Training in Anaesthesia. OUP Oxford. p. 166. ISBN 978-0-19-151177-6. Archived from the original on September 10, 2017.
  8. ^ Yamada T (2011). Textbook of Gastroenterology. John Wiley & Sons. p. PT4008. ISBN 978-1-4443-5941-1. Archived from the original on September 10, 2017.
  9. ^ Ryder SD, Beckingham IJ (February 2001). "Other causes of parenchymal liver disease". BMJ (Clinical Research Ed.). 322 (7281): 290–2. doi:10.1136/bmj.322.7281.290. PMC 1119531. PMID 11157536.