greater than 60 mg/kg per 24-hour period for greater than 48 hours (may have abdominal pain, nausea or vomiting).greater than 150 mg/kg per 24-hour period for the preceding 48 hours.greater than 200 mg/kg over a single 24-hour period.Greater than 200 mg/kg < than eight hours from ingestion time Paracetamol dosing that may be associated with hepatic injury* Appropriate treatment commencing within eight hours of the overdose will prevent almost all serious hepatic injury. 1,3Īcetylcysteine is an effective antidote to paracetamol toxicity by increasing the synthesis and availability of glutathione and directly binding to NAPQI. Clinical or biochemical evidence of this damage may take up to 24 hours post overdose to become apparent. Depletion of glutathione occurs with higher production of NAPQI which subsequently binds to other proteins and thus damages hepatocytes. The remaining 10% requires cytochrome p450 to make an intermediary compound of N-Acetyl-p-benzoquinone imine (NAPQI) which then in turn binds to intracellular glutathione for renal excretion. 1 Hepatic biotransformation results in 90% of paracetamol being metabolised to isubstrate sulphate and glucuronide conjugates which are then excreted by the kidneys. Distribution then occurs within two hours for liquid preparations and four hours for standard tablet preparations. Paracetamol is rapidly absorbed in the small intestine and reaches peak concentrations within 30 minutes for liquid preparations and one to two hours for standard tablet preparations. While there are certain groups who are at higher risk of hepatotoxicity (such as those with malnutrition, eating disorders, cystic fibrosis or acute viral infections) the recommended management is conservative and so remains unchanged.
This guideline is based on the recommendations made in 2020 by a group of Australasian Clinical Toxicologists consulting to the Poisons Information Centre.
This can be prevented by the early administration of acetylcysteine.
Accidental or deliberate overdose can cause hepatic failure and death. Paracetamol is a widely used analgesic that is readily available in many different preparations.
0 kommentar(er)
