xylazine in humans

Xylazine (Xylazine HCl) is an alpha-2-adrenergic agonist (α2- adrenergic agonist) that is used as a sedative and analgesic agent in a variety of species, as well as an emetic in cats. It is FDA-approved for use in dogs, cats, horses, deer, and elk to produce a state of sedation with a shorter period of analgesia and as a preanesthetic agent before local anesthesia. It is also approved as a preanesthetic agent before general anesthesia in dogs, cats, and horses.1 Xylazine has a long-standing use for surgical procedures in small animal practices, but it is also used in large animal and wildlife applications. In veterinary anesthesia, xylazine is often used in combination with ketamine. xylazine in humans

The sedative and analgesic activity of xylazine is related to central nervous system depression. It provides muscle relaxation based on inhibition of the intraneural transmission of impulses in the central nervous system.2 The degree of CNS inhibition is such that xylazine provides dose-dependent, deep muscle relaxation and respiratory depression without inhibition of the nervous system’s more critical functions.

Comparative pharmacokinetics of xylazine in several species was reported by researchers in 1981. Xylazine drug was administered intravenously and intramuscularly at recommended doses. The data was generated by analyzing serum drug concentration in samples obtained at 1, 2, 4, 8, 16, 30 and 120 min after xylazine administration. Compartmental analysis of the data was performed and the data best fitted a two-compartment open model.3,4