title: False-positive interferences of common urine drug screen immunoassays: a review.
abstract: Urine drug screen (UDS) immunoassays are a quick and inexpensive method for determining the presence of drugs of abuse. Many cross-reactivities exist with other analytes, potentially causing a false-positive result in an initial drug screen. Knowledge of these potential interferents is important in determining a course of action for patient care. We present an inclusive review of analytes causing false-positive interferences with drugs-of-abuse UDS immunoassays, which covers the literature from the year 2000 to present. English language articles were searched via the SciFinder platform with the strings 'false positive [drug] urine' yielding 173 articles. These articles were then carefully analyzed and condensed to 62 that included data on causes of false-positive results. The discussion is separated into six sections by drug class with a corresponding table of cross-reacting compounds for quick reference. False-positive results were described for amphetamines, opiates, benzodiazepines, cannabinoids, tricyclic antidepressants, phencyclidine, lysergic acid diethylamide and barbiturates. These false-positive results support the generally accepted practice that immunoassay positive results are considered presumptive until confirmed by a second independent chemical technique.
authors.affiliation: Department of Pathology, Center for Advanced Laboratory Medicine, University of California, San Diego Health Systems, San Diego, CA 92121, USA asaitman@ucsd.edu.
authors.forename: Alec
authors.initials: A
authors.lastname: Saitman
authors.affiliation: Department of Pathology, Center for Advanced Laboratory Medicine, University of California, San Diego Health Systems, San Diego, CA 92121, USA Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Hyung-Doo
authors.initials: HD
authors.lastname: Park
authors.affiliation: Department of Pathology, Center for Advanced Laboratory Medicine, University of California, San Diego Health Systems, San Diego, CA 92121, USA.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Fitzgerald
mesh_terms: D005189:False Positive Reactions; D006801:Humans; D013287:Illicit Drugs / Q000652:urine*; D007118:Immunoassay; D015813:Substance Abuse Detection / Q000379:methods* / Q000592:standards; D019966:Substance-Related Disorders / Q000652:urine*
chemical_list: D013287:Illicit Drugs