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1
Urine drug tests commonly use immunoassays that provide rapid presumptive results but have important limitations, including cross-reactivity, false negatives, and prolonged detection.
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2
Routine opiate immunoassays do not detect fentanyl, methadone, or buprenorphine, and benzodiazepine assays may miss clonazepam and designer benzodiazepines.
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3
In studies, clinicians often misinterpreted urine drug test results, and three clinical cases described patient harm after care was guided by misleading findings.
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4
The authors advocate residency education on judicious testing, consent, assay methods, detection windows, false results, toxidromes, and confirmatory testing.
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5
The authors also call for modernizing urine drug tests to address the changing drug supply and limitations of assays developed more than 50 years ago.
