Accidental or intentional assumption of excessive amount of paracetamol. Toxic dose: >150 mg/kg or >7.5 g (200 mg/kg for children <6 years)
Clinical features
- First 24 hours: asymptomatic or aspecific symptoms such as nausea and vomiting, malaise, anorexia, abdominal pain
- In patients with mild poisoning, symptoms will resolve and patient will recover. In patients with severe poisoning, symptoms will progress to the next phase
- In 24-72 hours: progressive signs of hepatic toxicity (e.g. right upper quadrant abdominal pain, enlarged tender liver, increased transaminases)
- After 72 hours: signs and symptoms peak at 72-96 hours and this may be followed by full recovery in 5-7 days or progression into irreversible hepatic failure (less frequently renal failure) and death
Investigations
- Monitor liver function, renal funtion, INR
- Rule out pregnancy (it crosses the placental barrier)
Management
- Treatment LOC
- Give repeated doses of activated charcoal (25-50 g every 4 hours)
- If ingestion was <2 hours, empty the stomach to remove any remaining medicine using gastric lavage
- Give acetylcysteine IV preferrably within 8 hours from ingestion; if patient presents later, give it anyway
- 150 mg/kg (max 15 g) in 200 ml of Dextrose 5% in 60 minutes followed by
- 50 mg/kg (max 5 g) in Dextrose 5% 500 ml in 4 hours followed by
- 100 mg/kg (max 10 g) in Dextrose 5% 1000 ml in 16 hours
- Supportive treatment
Note
- Acetylcysteine may cause histamine release, mimicking an allergic reaction. If patient is stable, slow the infusion. If bronchospasm, stop the infusion