A Case of False-positive Amphetamine Results on Urine Toxicology Testing Secondary to Imatinib

Abstract

In this case report, we describe a case of imatinib leading to a false-positive amphetamine result on urine drug testing. A 21-year-old female with chronic myelocytic leukemia and in recovery from opioid use disorder reinitiated imatinib maintenance therapy in her third trimester, after previous discontinuation at the beginning of pregnancy. Subsequently, she had multiple presumptive immunoassay-based urine drug tests that resulted positive for amphetamines. The infant's meconium testing was negative for amphetamines, as was maternal definitive testing using urine gas chromatography-mass spectrometry. She had no history of stimulant use and denied any substance use during her pregnancy. Imatinib and/or its metabolites may be responsible for cross-reactivity with urine drug immunoassays leading to a false-positive result for amphetamine.