Psychiatric and non-psychiatric drugs causing false-positive amphetamines urine test in psychiatric patients: a pharmacovigilance analysis using FAERS

ABSTRACT

Introduction

Immunoassay urine drug screen (UDS) is frequently used in clinical practice for initial screening process, being generally available, fast, and inexpensive. Exposure to widely prescribed drugs might determine false-positive UDS amphetamines, leading to diagnostic issues, wrong therapeutic choices, impairment of physician–patient relationship, and legal implications.

Areas covered

To summarize and comment on a comprehensive list of compounds responsible for UDS false positives for amphetamines, we conducted a literature review on PubMed along with a comparison with Real-World Data from the Food and Drug Administration Adverse Event Reporting System (FAERS) database analysis between 2010 and 2022. Forty-four articles and 125 Individual Case Safety Reports (ICSR) involving false-positive amphetamine UDS in psychiatric patients were retrieved from FAERS.

Expert opinion

False-positive results were described in literature for antidepressants, atomoxetine, methylphenidate, and antipsychotics, but also for non-psychiatric drugs of common use, such as labetalol, fenofibrate, and metformin. Immunoassay method is usually responsible for false-positive results, and in most cases, mass spectrometry (MS) does not eventually confirm the UDS positivity. Physicians should be aware of immunoassays’ limitations and when turning to a confirmatory test. Any new cross-reaction should be reported to pharmacovigilance activities.

KEYWORDS:

• Amphetamines
• cross-reaction
• urine
• false-positive test
• pharmacovigilance
• urine drug screening
• substance use disorder
• immunoassay

Article highlights

• Immunoassay urine drug screen (UDS) is generally available, fast, and inexpensive but often responsible for false-positive amphetamine results.

• False-positive UDS amphetamines lead to diagnostic and therapeutic errors, poor physician–patient relationship, and legal problems.

• A literature review and a comparison with one of the largest spontaneous pharmacovigilance reporting systems were conducted.

• Several and commonly used psychiatric and non-psychiatric drugs were found to be responsible for false-positive amphetamine UDS.

• Clinicians should be aware of UDS limitations, when turning to a confirmatory test and report any new cross-reaction to pharmacovigilance activities.

Acknowledgments

V Battini is enrolled in a PhD in Experimental and Clinical Pharmacological Sciences, Università degli Studi di Milano, which supports her fellowship.

Declaration of interest

B Dell’Osso has received lecture honoraria from Angelini, Janssen, Lundbeck, Bromatech, Otzuka, and Neuraxpharm. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Author contributions

V Battini and G Cirnigliaro conceived and designed the study. V Battini, G Cirnigliaro, G Mosini, L Giacovelli, M Boscacci, S Massara Manzo, G Guarnieri, and M Gringeri performed the research and analyzed the data. V Battini, G Cirnigliaro, and L Giacovelli wrote the original draft and C Carnovale, B Benatti, E Clementi, and B Dell’Osso reviewed and edited with inputs from all authors. C Carnovale, B Benatti, E Clementi, and B Dell’Osso participated in the interpretation of the data and revised and approved the final article as submitted.

Data availability statement

The data underlying this article will be shared on reasonable request to the corresponding author.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/17512433.2023.2211261

Additional information

Funding

This paper was not funded.