Q&A column

Editor: Frederick L. Kiechle, MD, PhD

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Q. In a case of suspected drug-related death, how specific can an autopsy be in identifying the drug(s) that might have caused the person’s death and the amount of drugs present? For example, can a toxicology report say a person’s death was caused by a fake oxycodone pill containing fentanyl?

A.February 2024—An autopsy usually includes toxicology testing, especially in a suspected drug-related death. However, toxicology testing alone is not typically sufficient to determine the cause of death. Toxicology testing, usually performed on blood, first determines whether drugs are present, the identity of the drugs, and the concentrations. These results can help the pathologist determine whether the drugs identified are sufficient to be toxic and account for death. However, it is rarely possible to determine how much of a drug (i.e. the dose) led to the death. Sometimes a single drug may cause death, but often a combination of drugs or alcohol may be responsible.

Toxicology testing alone can rarely tell where the drug came from or how it got into the body (e.g. by mouth, smoking, injection, or other routes). For example, illicit tablets designed to look like pharmaceutical oxycodone tablets have been circulating in North America. Often these tablets contain fentanyl or other opioid painkillers in amounts that may be life threatening to people who lack sufficient opioid tolerance.

More recently, the illicit “fake pills” have been partially superseded by powdered material that may be designed to look like heroin. These powders typically contain little or no heroin, the primary ingredient being fentanyl or another potent opioid (occasionally carfentanil, isotonitazene, or a related opioid). Increasingly, these powders may also contain a sedative such as an illicit benzodiazepine tranquilizer (e.g. etizolam) or the veterinary sedative xylazine. The sedative component of these illicit mixtures is reputed to prolong the “high” of the opioid (e.g. fentanyl). The addition of the sedative component can increase the toxicity of the opioid, which is also primarily a sedative, and that effect is not reversed by naloxone.

In some jurisdictions, drug paraphernalia found at the scene of death (e.g. syringes, powdered drug residue, illicit pills) may be examined, although that is not common in routine death investigations. Unfortunately, it is now common to find multiple drugs in an illicit pill or powder, all of which may have contributed to death to some degree, although in most such mixtures, the opioid is the dominant drug and is primarily responsible for the death.

Ultimately, the final cause of death is determined by an evaluation of the circumstances of death, the autopsy, toxicology testing, medical history, and the scene-of-death investigation. In deaths in which multiple drugs are involved, it is unusual to single out a specific drug as the cause of death because multiple drugs may have contributed to at least some toxicity.

Graham R. Jones, PhD
Forensic Toxicologist
Clinical Professor
Department of Laboratory Medicine and Pathology
University of Alberta
Edmonton, Alberta, Canada
Member, CAP Toxicology Committee