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Delayed and prolonged elevated serum paracetamol level after an overdose - possible causes and implications.
Shailesh Bihari1, Santosh Verghese, Andrew D Bersten
1Intensive Care Unit, Flinders Medical Centre, Adelaide, SA, Australia. biharishailesh@gmail.com
Summary
A large paracetamol overdose can cause delayed toxicity, even with initial normal levels. Extended monitoring of paracetamol levels and liver function is crucial before stopping N-acetylcysteine (NAC) treatment.
Area of Science:
- Toxicology
- Pharmacology
- Hepatology
Background:
- Paracetamol (acetaminophen) overdose is a common cause of acute liver injury.
- N-acetylcysteine (NAC) is the standard antidote for paracetamol poisoning.
- Early treatment with NAC is generally effective in preventing liver damage.
Observation:
- A 29-year-old male presented with a massive paracetamol overdose (50g).
- Initial serum paracetamol levels were low, and NAC infusion was stopped after 36 hours.
- Delayed and prolonged elevation of serum paracetamol levels was observed, peaking at 54 hours and lasting 5 days.
Findings:
- Despite initial NAC treatment, the patient developed fulminant hepatic failure.
- Liver function deteriorated on Day 3 with a resurgence of high paracetamol levels, necessitating reinitiation of NAC.
- This case highlights a delayed toxicity pattern in massive paracetamol overdose.
Implications:
- Continuous monitoring of serum paracetamol levels and liver function for at least 72 hours is essential after significant overdose.
- Discontinuation of NAC should be based on sustained normalization of paracetamol levels and liver enzymes, not solely on initial presentation.
- This case underscores the need for revised guidelines on NAC treatment duration in massive paracetamol ingestions.
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