Canadian Journal of Cardiology

The Interpretation of Toxicology Screening Tests for Substances With Abuse Potential: A Primer for the Cardiovascular Specialist

  • Emily Austin
    Corresponding author: Dr Emily Austin, Department of Emergency Medicine, St Michael’s Hospital, 30 Bond Street, Toronto, Ontario M5B 1W8, Canada. Tel.: +1-416-864-5095.
    Division of Emergency Medicine, University of Toronto, Toronto, Ontario, Canada

    Division of Clinical Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada

    Ontario Poison Centre, Hospital for Sick Children, Toronto, Ontario, Canada
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  • Marco L.A. Sivilotti
    Department of Emergency Medicine, Queen’s University, Kingston, Ontario, Canada

    Department of Biomedical and Molecular Sciences, Queen’s University, Kingston, Ontario, Canada

    Ontario Poison Centre, Hospital for Sick Children, Toronto, Ontario, Canada
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      Urine drug screens (UDS) are widely encountered across medical disciplines, including the cardiovascular subspecialties. The proper interpretation of such a readily available and seemingly simple qualitative test can be more complicated than anticipated. Urine immunoassay tests are limited by false positive and false negative results, which vary by commercial assay and manufacturer. Confirmatory testing can be useful in some specific scenarios but requires specialised toxicology laboratories for sample processing and interpretation. An appreciation for the techniques and limits of UDS will help all clinicians, including cardiovascular specialists, to interpret test results appropriately and steward resources judiciously.
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