21 Paracetamol Overdose Flashcards
(26 cards)
What dose can paracetamol cause hepatotoxicity?
20mg/kg
What is the biggest pack size that can be sold to the public?
16 in supermarkets, 32 in pharmacies
What is the max amount of dose units a pharmacist can sell?
100
What is the OTC selling limit of effervescent tablets?
No limit
What is IV paracetamol for?
Short term treatment of moderate pain and fever if other clinical administration routes not possible
What are the advantages of using IV paracetamol?
Very rapid, removes variability in absorption, reduces opioid dose requirements
What are the disadvantages of IV paracetamol?
Dose based on body weight
What is the dosage for paracetamol for adults?
0.5g to 1g every 4-6 hours, max of 4g
What is the dosage for paracetamol for a child or adult 10-50kg?
15mg/kg every 4-6 hours to a max of 60mg/kg daily
What is the maximum IV paracetamol dosage for adults over 50kg?
750mg every 4-6 hours, max 3g daily
What is the maximum IV paracetamol dosage for an adult under 50kg?
600mg every 4-6 hours, max 2.4g daily
What factors increase the risk of toxicity?
Increased rate of NAPQI formation, glutathione depletion and abnormal renal or hepatic function
How is increased rate of NAPQI formation detected?
By abnormal LFTs - increased INR and GGT
What is glutathione depletion caused by?
Malnourishment, eating disorders
What are the initial symptoms of liver damage?
Nausea and vomiting
What are the other symptoms of liver damage?
Jaundice, liver pain or tenderness, impaired consciousness, asterixis, foetor hepaticus, haemorrhage and elevated LFTs
What is foetor hepaticus?
Sweet faecal smell in breath
How long does complete liver failure take?
2-3 days
When should you consider oral activated charcoal in overdoses?
If less than 8 hours after ingestion or >150mg/kg in less than an hour
Until when is paracetamol absorption incomplete?
4 hours after ingestion
When is prognostic value reduced?
After 16 hours
What antidote is given for paracetamol overdose?
N-acetylcysteine
When should you not give the nomogram?
If the timing of paracetamol ingestion is unclear
How is N-acetylcysteine given?
By IV infusion over 60 mins depending on weight
