Paracetamol

Chemical Pathology

Notes

• In cases of paracetamol overdose please access TOXBASE, the database of the National Poisons Information Service (NPIS), or contact the helpline for medical professionals (telephone 0844 892 0111) for advice on risk assessment and management.
• Information and a treatment graph can also be found in the latest edition of the BNF.

Sample requirements

• Samples should normally be collected at 4 hours or more after a suspected overdose.
• Sampling before this time is not considered reliable as drug absorption and tissue distribution may stil be active.
• Further sampling after this time is unlikely to be helpful to clinical management.
• Also request liver function tests on the same sample (LFTs).

For adults, blood taken into a 5mL gold top gel tube (or rust top for the Acute Unit)

For children, blood taken into a 3.5mL rust top gel tube

For infants, blood taken into a 0.8mL minicollect lithium heparin tube

Storage/transport

Send at ambient temperature to the laboratory.

Required information

Relevant clinical details, including time of ingestion, dose/number of tablets if known and time blood sample taken.

Turnaround times

The assays are run throughout the day and night.

The in-lab turnaround time is less than 24 hours.

The test can be ordered as an urgent request.

Interpretation of results

• Results are reported in mg/L.
• Please refer to TOXBASE or BNF as indicated above for information on risk assessment and management.