Abstract
Xylazine, commonly called ¿tranq¿ or ¿sleep cut¿, is a strong ¿2-adrenergic
agonist used in veterinary practice as a sedative, analgesic, and muscle-relaxing agent. It
has never been approved by the Food and Drug Administration for human use, but its use
by people is on the rise. In the last decades, due to its low cost and ease of availability, it
has often been illicitly used due to its abuse potential as a drug for attempted sexual assault
and intended poisoning. In addition, xylazine¿s presence in the human body has also been
related to domestic accidental events. Generally, it is combined with multiple other drugs,
typically by intravenous injection, potentiating the doping effects. Xylazine¿s mechanism
of action is different from that of other illicit opioids, such as heroin and fentanyl, and
it has no known antidote approved for use in humans. The combination with fentanyl
prolongs the euphoric sensation and may heighten the risk of fatal overdose. Furthermore,
it may cause adverse effects, including central nervous system (CNS) and respiratory
depression, bradycardia, hypotension, and even death. Recent reports of xylazine misuse
have risen alarmingly and describe people who become ¿zombies¿ because of the drug¿s
harmful effects on the human body, including serious wound formation that could even
lead to limb amputation. This paper is an extensive review of the existing literature about
xylazine and specifically deals with the chemistry, pharmacokinetics, pharmacodynamic,
and toxicological aspects of this compound, highlighting the most recent studies.
