New recommendations for paracetamol poisoning

Recent evidence has prompted a change in the management of paracetamol poisoning, according the authors of the updated guideline summary published online today by the Medical Journal of Australia.

Previous guidelines were published by the MJA in 2015 but further research has emerged, particularly regarding acetylcysteine regimens, massive paracetamol ingestions, and modified release paracetamol ingestion.

The authors, led by Dr. Angela Chiew, an emergency physician and toxicologist at the Prince of Wales Hospital and a clinical toxicologist at the NSW Poisons Information Centre, made three adjusted recommendations to reflect that evidence.

1. The new guidelines recommend a two-bag acetylcysteine infusion regimen (200 mg/kg over 4 hours, then 100 mg/kg over 16 hour); this has similar efficacy but significantly reduced adverse reactions compared with the previous three-bag regimen.

2. Massive paracetamol overdoses that result in high paracetamol concentrations more than double the paracetamol nomogram line should be managed with an increased dose of acetylcysteine.

3. All potentially toxic modified release paracetamol ingestions (≥ 10 g or ≥ 200 mg/kg, whichever is less) should receive a full course of acetylcysteine. Patients ingesting ≥ 30 g or ≥ 500 mg/kg should receive increased doses of acetylcysteine.

In addition, Chiew et al included a management flow chart for rural and remote centres with limited pathology facilities.

"Many rural and remote health care facilities do not have access to 24-hour pathology or have very limited pathology services (eg, point of care testing only)," they wrote.

"These facilities can still manage certain acute paracetamol poisoning cases, provided acetylcysteine is available and the patient is not at high risk of developing acute liver injury.

[We have outlined] the management of acute immediate release paracetamol ingestion for rural and remote facilities and the criteria for determining when transfer is required."

A link to the full updated guidelines are available with Supporting Information published with the online version of the guideline summary.