Concurrent detection of heroin, fentanyl, and xylazine in seven drug-related deaths reported from the Philadelphia Medical Examiner's Office

J Forensic Sci. 2008 Mar;53(2):495-8. doi: 10.1111/j.1556-4029.2007.00648.x. Epub 2008 Feb 14.


Recreational drugs, such as cocaine and heroin, are often adulterated with other pharmacological agents to either enhance or diminish the drug effects. Between April 21, 2006 and August 8, 2006, the Philadelphia Medical Examiner's Office detected xylazine (a veterinary sedative) and fentanyl (a synthetic opioid) in specimens taken from seven cases. Initial immunoassay screening was performed on urine and blood for fentanyl, opiate, cocaine, phencyclidine (PCP), and benzodiazepines. All tests reported positive were confirmed by gas chromatography-mass spectrometry. All seven xylazine positive cases tested positive for fentanyl and six cases tested positive for 6-acetylmorphine (a metabolite and definitive marker for heroin). The seventh case was positive for morphine and had a history of heroin abuse. Xylazine was present in urine in all seven cases and blood levels were detected in three cases. The blood concentrations ranged from trace to 130 ng/mL. Fentanyl was present in the blood and urine in each case and blood concentrations ranged from 4.7 to 47 ng/mL. Adulteration of illicit drugs has become an epidemic health concern for drug users. Healthcare professionals need to be aware of this issue, so the patients can be treated in an effective, timely manner.

Publication types

  • Case Reports

MeSH terms

  • Adult
  • Coroners and Medical Examiners
  • Drug Contamination
  • Fentanyl / analysis*
  • Forensic Toxicology
  • Gas Chromatography-Mass Spectrometry
  • Heroin / analysis*
  • Humans
  • Hypnotics and Sedatives / analysis*
  • Illicit Drugs / chemistry
  • Male
  • Middle Aged
  • Narcotics / analysis*
  • Philadelphia
  • Xylazine / analysis*


  • Hypnotics and Sedatives
  • Illicit Drugs
  • Narcotics
  • Xylazine
  • Heroin
  • Fentanyl