Hepatotoxicity in a child following an accidental overdose of liquid paracetamol.

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