Paracetamol Overdose Flashcards
What is Paracetamol overdose?
Excessive ingestion of paracetamol causing toxicity
What are the maximum recommended limits of paracetamol?
2 x 500 mg tablets
4 x in 24 hrs
(in adults >50kg)
List 5 risk factors for paracetamol overdose
Chronic alcohol abusers
Pts on enzyme-inducing drugs (e.g. anticonvulsants)
Malnourished
Glutathione def: more at risk of liver damage following OD
HIV
Intake of how much paracetamol can cause hepatic necrosis?
Intake of 150mg/kg or > 12g in adults
But, prompt tx can prevent liver failure+ death
What is it important to establish in a patient presenting with paracetamol overdose?
TIMING + QUANTITY of OD + presence of RFs
Describe symptoms and signs experienced in the first 24 hours from OD
ASYMPTOMATIC usually
Mild N+V
Lethargy
Malaise
List 3 symptoms seen between 24-72 hours after paracetamol overdose
RUQ pain
Vomiting
Liver enlargement + tenderness
List 5 symptoms and signs seen from 72 hours after paracetamol OD
Increased confusion, decreased consciousness level or asterixis (encephalopathy) Jaundice Coagulopathy Hypoglycaemia Renal angle tenderness +/- AKI
What investigation is used in suspected paracetamol overdose
Measure paracetamol levels
Peak paracetamol levels are 4 hrs after ingestion
What bloods should be taken in paracetamol OD?
FBC
U+Es: may show renal impairment; hepatorenal syndrome
Glucose: prone to hypoglycaemia
LFTs: deranged
Clotting Screen: PT prolonged, INR increased
Lactate elevated
ABG
What drug is used to treat paracetamol OD?
N-ACETYLCYSTEINE
What is considered the “deadly time” after paracetamol OD?
People usually die within day 2-5
What is the prognosis of people who take a paracetamol OD?
liver recovers completely after they recover from the OD.
If a patient presents within 1 hour of taking a paracetamol overdose, how are they treated?
Will likely be asymptomatic
May give activated charcoal (reduces absorption of paracetamol)
Check paracetamol levels 4 hours post ingestion to determine true OD + dose of N-acetylcysteine
