Electrochemical Point-of-Care Test for Assessing Serum Paracetamol Concentration: Comparison With Traditional Methods...

Rapid serum paracetamol (acetaminophen) concentration measurement is essential in suspected intoxication, but centralized laboratory analyses often delay initiation of antidotal therapy. We studied the feasibility of a novel electrochemical single-walled carbon nanotube/Nafion-based point-of-care (POC) method in detecting paracetamol in 99 suspected overdose patient serum samples. POC was compared with the standard photoelectric enzymatic method (PEM) and ultra-high performance liquid chromatography-photodiode array and corona-charged aerosol detector (UHPLC-DAD-CAD). We also analysed for 900 concomitant pharmaceuticals, drugs and chemicals in 197 samples with time-of-flight mass spectrometry to assess interference with paracetamol concentration measurements. Paracetamol concentrations measured with UHPLC-DAD-CAD ranged between 0 and 2100 μmol/L, with 19% above the therapeutic level (≥ 200 μmol/L). Comparing POC with UHPLC-DAD-CAD, the false positives and negatives were 10% and 15%, respectively, at concentrations ≥ 30 μmol/L. All POC method false negatives occurred at concentrations < 45 μmol/L. PEM showed 8% false positives and negatives compared with UHPLC-DAD-CAD. Other substances detected included caffeine (78%), antidepressants (41%), benzodiazepines (34%) and antipsychotics (28%). They did not interfere with POC concentration measurement. The novel POC method is promising for measuring serum paracetamol at relevant concentrations.