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Fenfluramine: An Uncommon Cause of False Positive Urine Drug Testing: A Case Report
Maria Ghawji1,2, Meagan Hainlen1,2, Charuta Joshi1,2
1Children's Medical Center Dallas Texas USA.
Background:
Fenfluramine is an antiseizure medication approved by the Food and Drug Administration for the treatment of Dravet syndrome in patients older than 2 years. Fenfluramine is an amphetamine derivative. It cross-reacts with amphetamines in urine drug screen immunoassays.
Patient Presentation:
A 2-year-old patient with Dravet syndrome had a cardiorespiratory arrest and tested positive for amphetamines in a urine drug screen, raising concerns of child abuse. Liquid chromatography-mass spectrometry confirmed the presence of fenfluramine but did not detect amphetamines.
Conclusion:
Fenfluramine can result in a false-positive amphetamine urine drug screen at the recommended dose for Dravet syndrome. Awareness of this potential cross-reactivity can prevent undue child protective services reports, especially in patients at high risk for sudden death.
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