False-Positive Urine Screening for Benzodiazepines: An Association with Sertraline?: A Two-year Retrospective Chart Analysis

Abstract

Objective: To determine the frequency of false-positive benzodiazepine screens associated with sertraline use at the authors' institution.

Method: Urine drug screen results spanning a two-year period were data mined to identify those positive for benzodiazepines. When confirmatory gas chromatography-mass spectrometry determined false positives, they were subsequently cross-referenced against pharmacy records to identify patients with active prescriptions for sertraline at the time of the initial urinary drug screen.

Results: Of the 522 records reviewed, 160 were later determined to be false positives by confirmatory gas chromatography-mass spectrometry. Sixty-two of those were associated with a concomitant benzodiazepine prescription. Of the 98 remaining, 26 were associated with a concomitant sertraline prescription.

Conclusion: Our findings suggest that sertraline may be an unreported cause of false-positive benzodiazepine results in a widely used screening assay.

Keywords: benzodiazepines; false positive; screening assay; sertraline; urine drug screening.

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Summary of data