Detection of Clenbuterol in Heroin Users in Twelve Postmortem Cases at the Philadelphia Medical Examiner's Office

The presence of clenbuterol, a beta2-adrenergic agonist banned for human use in the United States because of its serious side effects, is reported in a series of 12 postmortem cases in which the cause of death was attributed to illicit drug use. During the first three months of 2007, postmortem specimens from cases previously screening positive for opiates or fentanyl were screened specifically for clenbuterol using enzyme-linked immunosorbent assay. Confirmation of clenbuterol was performed using solid-phase extraction, derivatization with trimethylboroxine, and analysis utilizing a gas chromatograph-mass spectrometer (GC-MS) operated in the full-scan mode. The limits of detection and quantitation in blood were 2.5 and 5 ng/mL, respectively. Linearity was from 5 to 100 ng/mL. Clenbuterol was positive in 12/106 (11%) drug-related cases and in 12/575 (2.1%) of the total cases tested. In each of the 12 cases positive for clenbuterol, heroin use was either confirmed by the presence of 6-acetylmorphine or strongly suspected by the presence of morphine with a history of heroin abuse. Because the use of clenbuterol in the United States is restricted to veterinary medicine, its detection is an unexpected finding. Its presence in these cases serves as a caution to emergency room physicians and toxicologists to consider and test for clenbuterol when treating a suspected heroin user who presents atypically. This is the first known series of clenbuterol-positive cases of illicit drug users to be reported from a medical examiner's toxicology laboratory.