Emergence of Medetomidine in North America

"The ongoing adulteration of pharmaceutical products in the illegal drug supply poses significant public health and safety risks in many communities. Recently, the incorporation of medetomidine—a potent, nonopioid sedative—transformed the fentanyl supply in Philadelphia, leading to severe medical complications from a novel withdrawal syndrome [1]. Drug checking programs and forensic laboratories first detected medetomidine in street opioid samples in 2022 [2]. By 2023–2024, medetomidine was identified in multiple U.S. states and Canada as a co-contaminant in fentanyl or heroin preparations [3]. One of Pennsylvania’s drug checking programs, PAGroundhogs (PAG), confirmed that 61% of the total dope samples tested since April 2024 (169 samples) showed positivity for medetomidine and had surpassed xylazine, which was the previous most prevalent adulterant (present in up to 99% of fentanyl samples in 2023) [4]. Many medetomidine-positive samples in Philadelphia also contained xylazine and fentanyl, indicating that medetomidine is entering the street supply as part of the evolving mixture often referred to as tranq (traditionally associated with xylazine–fentanyl combinations) and now referred to as demon (fentanyl–medetomidine ± xylazine combination) [5]. Similar findings were reported in alerts and media reports of overdose clusters outside of Philadelphia, spreading west in 2024, prompting public health warnings about an “emergent adulterant” driving a new wave of overdoses [3]."