Retraining over the principles and mechanisms involved in the occurrence of false results from urine drug screening tests: Adulteration and strategies to defeat

Screening tests (UDSTs) for the diagnosis of psychoactive drugs can identify drug abuse, improve workplace safety, ensure community health, and play a critical role in therapeutic drug monitoring. Nonetheless, correct interpretation of the results of these tests requires a full awareness of the principles of testing methods, drug kinetics, and various leading causes of false results. Among the advantages of these screening tests (based on the immunoassay technique), we can refer to their high sensitivity in the detection of psychoactive substances, convenience, and cost-effectiveness. Therefore, these kinds of urine drug screening are recommended as the first line of detection in all reliable related guidelines. This method can reliably detect common drug abuse, such as opiates/opioids, amphetamine/methamphetamine, cocaine, cannabinoids, phencyclidine, barbiturates, and benzodiazepines, with high sensitivity. Although the immunoassay technique is sensitive to the presence of drugs/drug metabolites and has relatively good specificity, false negative and positive results may occur in some cases. Therefore, careful attention to proper sample collection methods and tests to determine the integrity nature of the urine sample can identify a wide range of abusers' attempts to produce false negative/positive test results. Finally, unexpected positive test results should be checked with confirmatory methods, such as gas chromatography/mass spectrometry.