Xylazine hydrochloride
[CAS# 23076-35-9]

Identification

• Classification: Biochemical >> Inhibitor >> Neuronal signaling >> Adrenergic receptor agonist
• Name: Xylazine hydrochloride
• Synonyms: 2-(2,6-Dimethylphenylamino)-5,6-dihydro-4H-thiazine hydrochloride
• Molecular Formula: C₁₂H₁₆N₂S.HCl
• Molecular Weight: 256.79
• CAS Registry Number: 23076-35-9
• EC Number: 245-417-0
• SMILES: CC1=C(C(=CC=C1)C)NC2=NCCCS2.Cl

Safety Data

• Hazard Symbols: GHS05;GHS06;GHS07 Danger
• Risk Statements: H301-H315-H318-H319-H335-H412
• Safety Statements: P261-P264-P264+P265-P270-P271-P273-P280-P301+P316-P302+P352-P304+P340-P305+P351+P338-P305+P354+P338-P317-P319-P321-P330-P332+P317-P337+P317-P362+P364-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Acute toxicity	Acute Tox.	3	H301
Skin irritation	Skin Irrit.	2	H315
Specific target organ toxicity - single exposure	STOT SE	3	H335
Eye irritation	Eye Irrit.	2	H319
Serious eye damage	Eye Dam.	1	H318
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Acute toxicity	Acute Tox.	4	H302
Acute toxicity	Acute Tox.	3	H311
Acute toxicity	Acute Tox.	4	H332
Acute toxicity	Acute Tox.	2	H300
Acute toxicity	Acute Tox.	3	H331
Specific target organ toxicity - single exposure	STOT SE	3	H336
Acute toxicity	Acute Tox.	4	H312

Discovery and Applications

Xylazine hydrochloride, a potent a2-adrenergic agonist, was discovered in the 1960s during research into new veterinary sedatives and analgesics. Synthesized as a derivative of clonidine, xylazine was initially investigated for its sedative and analgesic properties in animal models.

Xylazine hydrochloride is extensively used in veterinary medicine as a sedative, analgesic, and muscle relaxant for the restraint and immobilization of animals during medical procedures. It is commonly employed in companion animal practice for premedication before anesthesia induction and as an adjunct to general anesthesia to reduce anesthetic requirements and provide intraoperative analgesia. In large animal medicine, xylazine is used for sedation during minor surgical procedures, restraint for diagnostic imaging, and calming of agitated or fractious animals.

In the livestock industry, xylazine hydrochloride is utilized for sedation and immobilization of animals during handling, transportation, and medical procedures. It helps reduce stress and aggression in animals, facilitating safer and more efficient handling practices. Xylazine is often administered to cattle, sheep, and swine before castration, dehorning, or shearing procedures to minimize pain and distress.

Xylazine hydrochloride is a commonly used sedative and anesthetic agent in laboratory animal research. It is employed for immobilization and restraint of rodents, rabbits, and other small mammals during experimental procedures, such as blood sampling, injections, and surgical interventions. Xylazine-induced sedation provides researchers with a controlled and reversible state of unconsciousness, allowing for the precise manipulation and observation of animals without causing undue stress or pain.

Xylazine hydrochloride is utilized in wildlife management and conservation efforts for immobilization and anesthesia of wild animals. Veterinarians and wildlife biologists administer xylazine to immobilize animals temporarily for health assessments, tagging, tracking, and relocation purposes. The sedative effects of xylazine enable safe handling of wild animals while minimizing the risk of injury to both animals and personnel. Its reversible nature allows for the rapid recovery and release of animals back into their natural habitats.

In companion animal behavior management, xylazine hydrochloride is sometimes used as an adjunctive therapy for the management of behavioral disorders, such as anxiety, aggression, and compulsive behaviors. Its sedative properties help calm anxious or aggressive animals, facilitating behavior modification training and reducing the risk of injury to both animals and handlers.

References

1990. Xylazine enhances porcine myometrial contractility in vitro: possible involvement of alpha 2-adrenoceptors and Ca2+ channels. *Biology of Reproduction*, 43(4).
DOI: 10.1095/biolreprod43.4.614

1979. Rapid Inhibition of Basal and Glucose-Stimulated Insulin Release by Xylazine. *Endocrinology*, 105(4).
DOI: 10.1210/endo-105-4-920

1979. USE OF KETAMINE HYDROCHLORIDE AND XYLAZINE HYDROCHLORIDE TO IMMOBILIZE BLACK BEARS (Ursus americanus). *Journal of Wildlife Diseases*, 15(2).
DOI: 10.7589/0090-3558-15.2.253