Unintentional paediatric paracetamol overdose: a retrospective observational study of dosing errors reported to an Australian Poisons Information Centre

Paracetamol poisoning is the leading cause of paediatric acute liver failure in Australia. This study aimed to describe patterns and characteristics of unintentional paracetamol overdose in children, with a focus on dosing errors, reported to Australia’s largest Poisons Information Centre. Records regarding unintentional paracetamol overdose for individuals aged < 12 years old were extracted from the New South Wales Poisons Information Centre database, January 2017-June 2023. Dosing errors during 2021 underwent an in-depth screening of dose, duration, products involved, indications for use, the type of error and need for hospitalisation. Where possible, medical records of hospitalised exposures with dosing errors were screened across all years to obtain outcomes including hospital admission, length of stay, pathology test results, treatment, liver transplantations and deaths. Over-the-counter paracetamol sales data were obtained to examine the number of exposures per 100,000 units or grams sold. There were 17,318 unintentional paracetamol exposures including 10,189 dosing errors and 7129 accidental exposures. There was an increase in dosing errors with time, associated with COVID-19 outbreaks in Australia. In-depth analysis of exposures from 2021 was done on 1498 exposures (median age 1 year, 54.0% male) with 1.7% (n = 26) requiring hospitalisation. Liquid dosage forms were the most frequently involved with higher strengths the most implicated. A communication error between caregivers and strength/formulation selection errors were the most frequently cited reasons for error. In-depth analysis of hospitalised exposures during the entire study period, where medical records were accessible, identified 142 exposures (median age 1 year, 59.2% male). Of these, 10.6% (n = 15) were treated with the antidote, N-acetylcysteine. No cases of liver transplantation or death were identified and only 3.0% (n = 2) developed hepatotoxicity. Paracetamol dosing errors in children are common but are unlikely to cause hepatotoxicity and death. Avenues to reduce the occurrence of dosing errors may include caregiver education and standardisation of strength and packaging of liquid paracetamol products.