Hepatotoxicity in a child following an accidental overdose of liquid paracetamol

Abstract

Introduction: Accidental pediatric liquid paracetamol exposure is common. Most children do not require treatment with acetylcysteine and acute liver injury is rare.

Case report: An otherwise well 3-year-old (15.4 kg) girl with recent vomiting and low-grade fever presented 1 h post-accidental ingestion of up to 150 mL of 24 mg/mL (240 mg/kg) of liquid paracetamol. Paracetamol concentrations 2 and 4 h post-ingestion were 105 and 97 mg/L, respectively, both below the nomogram treatment threshold so acetylcysteine was not administered. The ALT was elevated to 52 U/L 4 h post-ingestion, and then 219 U/L at 17 h, so intravenous acetylcysteine was commenced at 25 h. ALT peaked at 1393 U/L 5d post-ingestion, and INR peaked at 1.5 at 44 h post-ingestion. Acetylcysteine continued for 64 h and she made an uneventful recovery. Paracetamol metabolites were measured including, nontoxic glucuronide and sulphate conjugates and toxic cytochrome P450 (CYP) metabolites (cysteine and mercapturate). The apparent paracetamol half-life was 6.3 h. Her CYP metabolites were higher than usual, 11% of total metabolites. Glucuronide and sulphate conjugates accounted for 71 and 18% of total metabolites, respectively.

Conclusion: This uncommon case of hepatotoxicity in a child following accidental liquid paracetamol ingestion may have been due to increased susceptibility from a recent viral illness with decreased oral intake, as evidenced by the higher proportion of CYP metabolites.

Keywords:

• Acetaminophen
• poisoning
• liver injury

Author contributions

Dr Angela Chiew drafted the initial manuscript, reviewed and revised the manuscript. She also performed all the pharmacokinetic calculations. Dr Genaro Domingo, Associate Prof Darren Roberts and Prof. Nicholas A Buckley were involved in drafting and reviewed and revised the manuscript. Ms Kirsty Ress and Dr Paul Stathakis performed the paracetamol metabolite assays and reviewed and revised the manuscript. All authors approved the final manuscript as submitted and agree to be accountable for all aspects of the work.

Disclosure statement

The authors have no financial or other conflicts of interest relevant to this article to disclose.

Additional information

Funding

This research was partially supported by an NHMRC Program Grant 1055176. DMR acknowledges support of the Clinician “Buy-Out” Program, St. Vincent’s Centre for Applied Medical Research.