False-Positive Lysergic Acid Diethylamide Immunoassay Screen Associated with Fentanyl Medication

The prevalence of lysergic acid diethylamide (LSD) use has steadily increased over the past two decades. The 2000 National Household Survey on Drug Abuse (1) estimated that of the population 12 years and older, 3.5% have tried LSD. With the increase in LSD and other illicit drug use, urine drug screening in occupational and clinical settings has likewise increased. In the toxicology laboratory of Hennepin County Medical Center, LSD is one of eight drugs screened in the routine urine immunoassay drugs-of-abuse panel. In this report, we describe several cases involving false-positive urine screens for LSD by either the CEDIA and/or SYVA Emit II immunoassays. In one case, two urine samples that were immunoassay positive for LSD failed to confirm either LSD or its metabolite 2-oxo-3-hydroxy LSD by liquid chromatography-mass spectrometry (LC-MS).The case involved a 31-year-old male with severe end-stage cardiomyopathy secondary to rheumatic heart disease and crack cocaine abuse. He called emergency medical services from home with complaints of shortness of breath. He was subsequently diagnosed with cardiogenic shock secondary to sepsis and cardiomyopathy. He was intubated and admitted to the coronary care unit for hemodynamic support including intraaortic balloon pump. His initial urine drug screen on admission was negative.The patient was treated for sepsis and gradually weaned from ventilatory and pressor support. The patient’s condition steadily improved. While in …