Trazodone-Associated False Positives in Drug Screens

Clinical Implications

The American College of Physicians recommends ordering confirmatory testing using gas chromatography-mass spectrometry (GC-MS) immediately before making any clinical decisions based on a positive amphetamine screen in patients taking trazodone 1, 2, 3
Obtaining a complete medication history, specifically asking about trazodone use, is crucial when interpreting any positive amphetamine/methamphetamine result 3, 4
The American Medical Association advises against discharging patients from practice or making punitive decisions based solely on immunoassay screening results without confirmatory testing 1

A positive amphetamine screen in a patient taking trazodone may be due to false positive from m-CPP cross-reactivity, actual amphetamine/methamphetamine use, other medication interferences, laboratory error, or self-treatment of uncontrolled symptoms 2, 4, 5

Assuming all positive amphetamine screens represent illicit drug use is incorrect, as many prescribed medications, including trazodone, cause false positives 3
Failing to recognize that standard enzyme-linked immunoassays are screening tests only with known specificity limitations can lead to misinterpretation of results 2, 5
Not establishing a working relationship with a local toxicologist for consultation on complex results can hinder accurate interpretation 1, 4

False-positive amphetamine screens occur in 3.9-9.9% of positive amphetamine immunoassays in clinical laboratories, highlighting the need for confirmatory testing, according to the American Society for Microbiology 6

Many healthcare providers have inadequate training in interpreting urine drug test results, which can lead to severe consequences, including legal implications, as noted by the Infectious Diseases Society of America 6

Self-treatment of uncontrolled psychiatric symptoms can lead to positive amphetamine screens 7
Many healthcare providers have inadequate training in interpreting urine drug test results, and incorrect interpretation can have severe consequences including legal implications 7
False-positive laboratory results are 8 times more frequent than true positives (1.8%) in patients with routine testing 8
Establishing a working relationship with a local toxicologist for consultation on complex results is recommended 7
Discussing unexpected positive results promptly with the patient in a non-judgmental manner before taking action, keeping in mind the possibility of false-positive results, is essential 7