Loperamide, a common over-the-counter antidiarrheal drug and opioid derivative, is formulated to act upon intestinal opioid receptors. However, at high doses, loperamide crosses the blood-brain barrier and reaches central opioid receptors in the brain, leading to central opiate effects including euphoria and respiratory depression. We report the case of a young man found dead in his residence with a known history of drug abuse. At autopsy, the only significant findings were a distended bladder and bloody oral purge. Drug screening found nontoxic levels of alprazolam, fluoxetine, and marijuana metabolites. Liquid chromatography time-of-flight mass spectrometry found an unusual set of split isotope peaks consistent with chlorine. On the basis of autopsy and toxicological findings, loperamide toxicity was suspected because of its opioid properties and molecular formula containing chlorine. A sample of loperamide was analyzed by liquid chromatography time-of-flight mass spectrometry, resulting in a matching mass and retention time to the decedent's sample. Subsequently, quantitative testing detected 63 ng/mL of loperamide or more than 6 times of therapeutic peak concentration. Cause of death was determined as “toxic effects of loperamide with fluoxetine and alprazolam.” Because of its opioid effects and easy accessibility, loperamide is known as “poor man's methadone” and may go undetected at medical and forensic drug screening.
From the *University of Texas Health Science Center at Houston; and †Harris County Institute of Forensic Sciences, Houston, TX.
Manuscript received June 10, 2015; accepted August 2, 2015.
The authors report no conflict of interest.
Reprints: Jennifer Dierksen, MD, 6431 Fannin St, MSB 2.262, Houston, TX 77030. E-mail: Jennifer.firstname.lastname@example.org.
The corresponding author will receive reimbursement for travel costs from her institution, the University of Texas Health Science Center at Houston Department of Pathology and Laboratory Medicine Residency Program, to present an oral presentation of an abstract that is the basis of this case report at the American Academy of Forensic Science 67th annual meeting in Orlando, FL, February 16–21, 2015.