Clinical background:
Paracetamol is a commonly used analgesic which, if taken in excessive amounts, can lead to toxic liver damage and renal impairment.
Specimen container paediatric:
Serum (SST or plain tube)
Specimen container adult:
Serum (SST or plain tube)
Minimum volume paediatric:
0.5 mL blood
Minimum volume adult:
1 mL blood
Special requirements:
Sample to be collected at least four hours post ingestion of the paracetamol.
Sample stability:
Unseparated sample: unknown
Separated sample: unknown at 15-25°C,
2 days at 2-4°C,
4 weeks at -20°C
Reference ranges:
Therapeutically the range varies but has been reported to be 10 – 30 mg/L.
High concentrations of paracetamol metabolites or treatment with N-Acetylcysteine (NAC) may result in falsely DECREASED results for creatinine, lactate, triglyceride, cholesterol, HDL-cholesterol and uric acid.
Factors affecting result:
Haemolysis, and some drugs interfere.
N-acetylcysteine interferes to an unpredictable extent, to give lower concentrations than the true value. Interferences of 10 -20% are typical levels, but can be very much higher.
Other info:
Lithium heparin plasma sample also acceptable