Overdose with modified-release paracetamol (Panadol Osteo®) presenting to a metropolitan emergency medicine network: a case series.

BACKGROUND

There are currently no large cases series documenting poisoning with paracetamol modified-release (Panadol Osteo®, GlaxoSmithKline, Sydney, NSW, Australia). Management guidelines recommend at least two serum paracetamol concentrations 4 h apart and initiating treatment with N-acetylcysteine (NAC) if more than 10 g is ingested.

OBJECTIVE

To describe a cohort of Panadol Osteo® poisoning and determine if the management of identified cases was consistent with existing guidelines.

METHOD

Descriptive retrospective case series presenting to a metropolitan hospital network with paracetamol poisoning from October 2009 to September 2013.

RESULTS

There were 42 cases of Panadol Osteo® poisoning identified. Twenty-nine patients (median ingested dose 19 950 mg) were treated with NAC, of which 27 were acute single ingestions. Of NAC-treated patients, 85% (23/27) had an initial serum paracetamol concentration that was above the nomogram line. However, 15% (4/27) had an initial non-toxic concentration that later increased above the line. In 14 untreated patients (median ingested dose 7980 mg), one was an unrecognised late line-crosser with initial non-toxic serum paracetamol concentration. Only 43% (6/14) had a repeat paracetamol concentration measured. Three patients had a 4 h paracetamol >500 μmol/L. Late line-crossing was seen in the NAC-treated group at this level. In two untreated patients, NAC should have been commenced on the reported dose.

CONCLUSION

Most patients presenting with Panadol Osteo® poisoning requiring NAC treatment had an initial serum paracetamol concentration indicating need for treatment. A small number of late treatment nomogram line-crossers was seen on repeat paracetamol estimation. The current guideline for Panadol Osteo® poisoning would have detected all cases requiring NAC treatment.