Forensic pathology and toxicological analyses: A case of fatal xylazine poisoning

Xylazine, an α₂-adrenergic receptor agonist commonly used as a veterinary sedative, has gained notoriety for its increasing misuse in combination with opioids, such as fentanyl, to potentiate its effects. This trend has led to a rise in cases of xylazine poisoning. Although timely diagnosis and intervention have reduced fatalities, the postmortem pathological manifestations and lethal blood concentration of xylazine alone remain poorly characterized due to its common co-occurrence in toxicology with fentanyl. This study presented a case of homicide involving fatal intoxication solely from xylazine overdose without coadministration of other central nervous system drugs, detailing the multi-organ pathological changes observed and quantifying the decedent's blood xylazine concentration at 13.34 μg/mL using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The findings aimed to provide forensic practitioners with valuable insights for the identification and investigation of fatal xylazine poisoning cases.