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&reg; = 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.

Related Articles

 * Antidepressant intoxication
 * Benzodiazepine intoxication

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

Used literature

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