Paracetamol intoxication

Paracetamol is one of the most widely used analgesics - antipyretics ( Paralen® ). The acetanilide derivative contained in paracetamol is biotransformed in the liver by cytochrome P450 into highly hepatotoxic N-acetyl-p-benzoquinonimine , which is immediately inactivated by glutathione in therapeutic doses . When glutathione is depleted, hepatocytes are damaged and centrizonal necrosis occurs . A similar biotransformation takes place in the kidneys → also necrosis and kidney damage

Toxicity

• Already a dose higher than 140 mg/kg' (70 kg human − 20 tablets of Paralen 500® = hepatotoxic dose),
• children are less sensitive (they do not have functional cytochrome P450),
• more sensitive are alcoholics, patients on antiepileptics.

Clinical picture

• Early symptoms' − nausea, vomiting,
• latency from ingestion (2−3 days) is typical,
• hepatorenal stage - symptoms of liver failure and renal failure, encephalopathy, rise in prothrombin time, metabolic acidosis, death.

Treatment

• Administer activated charcoal, suppress vomiting (metoclopramide),
• 'antidote - N-acetylcysteine initial dose 140-150 mg/kg, continued dose 70 mg/kg, the dosage varies according to the time of intoxication and the method of administration.
• indication is suspicion of ingestion or paracetamol value in plasma 200 mg/l or more in 2 h after ingestion,
• hemoperfusion is also effective.

Links

Related Articles

• Antidepressant intoxication
• Benzodiazepine intoxication

Source

BENEŠ, Jiří. Study materials  [online]. [cit. 24/02/2010].(http://jirben.wz.cz/)

References

• HODIS, Jiří. New facts about paracetamol, risks of overdose, intoxication and their management. Practical Pharmacy [online] . 2015, year 11, vol. 3, pages. 90-92, also available from < https://www.praktickelekarenstvi.cz/pdfs/lek/2015/03/03.pdf >. ISSN 1803-5329.

Used literature

• PELCLOVÁ, Daniela. Nemoci z povolání a intoxikace. 2. vydání. Praha : Karolinum, 2006. 207 s. ISBN 80-246-1183-X.