Evaluation of a urine screen for acetaminophen.
BACKGROUND
Acetaminophen (APAP) is a leading cause of fatal overdose. This study examined the performance characteristics of the Biosite Triage TOX Drug Screen qualitative APAP urine test (urine screen) in a clinical setting.


METHODS
Paired urine and serum waste samples (collected within 2 hours of one another) were quantitatively analyzed for APAP concentration and compared to the urine screen results.


RESULTS
A total of 191 paired samples met inclusion criteria. The urine screen did not report a negative result for the 21 samples with a serum APAP concentration of > or =10microg/mL and had a sensitivity of 100% (95% confidence interval [CI], 85-100%). The urine screen had a sensitivity of 96% (95% CI, 91-99%) and a specificity of 90% (95% CI, 82-95%) for detecting urine APAP concentrations > 5microg/mL by gas chromatograph mass spectroscopy (GCMS) methods, and a sensitivity of 81% (95% CI, 73-87%) and a specificity of 95% (95% CI, 85-98%) by high-pressure liquid chromatography (HPLC) methods.


CONCLUSIONS
The urine screen detected urine APAP concentrations with good accuracy and may be an effective screen to rule out acute APAP overdose in some circumstances. Its clinical utility is discussed.
Department of Emergency Medicine, University of Louisville School of Medicine, Louisville, KY, USA.
Daniel N
DN
Ingram
George N
GN
Bosse
Edward P
EP
Womack
Saeed
S
Jortani
D000082:Acetaminophen / Q000097:blood / Q000506:poisoning / Q000652:urine*; D018712:Analgesics, Non-Narcotic / Q000097:blood / Q000506:poisoning / Q000652:urine*; D002851:Chromatography, High Pressure Liquid; D062787:Drug Overdose / Q000175:diagnosis / Q000652:urine; D015200:Fluoroimmunoassay; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D018712:Analgesics, Non-Narcotic; D000082:Acetaminophen