Description
Xylazine is an α2-adrenergic agonist used as a veterinary anaesthetic. In recent years, xylazine has emerged as an adulterant in illicit drugs, especially opioids. Xylazine is known to produce intense sedative effects and skin wounds.
Desirable Effects
- Relaxation
- Sedation
- Anti-anxiety effects
Undesirable Effects
- Unconsciousness, slowed breathing and heart rate
- Skin wounds such as open sores and abscesses from repeated use
- Rapid and severe withdrawal symptoms including high blood pressure and high heart rate
What does it look like?
In its pure solid form, xylazine is a white or off-white crystalline powder or solid. For veterinary injections, xylazine comes as a clear liquid inside sterile glass vials
On the unregulated drugs market, xylazine is usually found in heroin powder, and occasionally opioid or benzodiazepine tablets of varying colours and forms. In these samples, you cannot see xylazine by eye.
Method of Use
Injection: Xylazine is administered by IV infusion to human patients in intensive care. Xylazine is given to animals by injection (intramuscular, intravenous, or subcutaneous).
Generally, human consumption of xylazine is incidental and would follow the route of administration of the adulterated drug of intent.
Pharmacology
Xylazine is a potent α2-adrenergic receptor agonist. By activating the α2-adrenergic receptor, xylazine disrupts nerve signals in the part of the nervous system involved in the fight-or-flight response. This produces a strong sedative effect, including slowing down heart rate.
The mechanism of xylazine wounds is still a topic of investigation. Skin popping during subcutaneous injection can result in inflammation and chronic ulceration. Xylazine’s activation of peripheral α2 receptors leads to vasoconstriction (narrowing of blood vessels) which may cause less blood to reach the extremities, where wounds are most commonly found.
Xylazine’s effects usually start 15–30 minutes after administration, and its sedative effects may last for up to 4 hours. Xylazine is metabolised rapidly in the liver by CYP450 enzymes and excreted in urine. Human tolerance to xylazine varies significantly, with fatal doses ranging between 40–2,400 mg.
Due to its nervous system depressant effects, medetomidine in combination with other depressants such as opioids can increase the risk of overdose. In an opioid overdose involving medetomidine, naloxone administration can reverse the opioid effects but the individual may remain heavily sedated.
History
Xylazine was developed by Farbenfabriken Bayer in 1962 as an antihypertensive agent. It was found to depress the central nervous system in human clinical trials, after which further human research was discontinued. Xylazine was instead marketed as a veterinary sedative, becoming one of the most common sedatives used for large animals in the 1970s.
Non-medical use of xylazine became more prominent in the 21st century. Xylazine was first found as an adulterant mixed with heroin in Puerto Rico in the early 2000s, before reaching mainland US in 2006. In 2019, xylazine detections surged in Canada, particularly western provinces like British Columbia. In 2021, xylazine reached Europe in combination with synthetic opioids, and the first xylazine-related death outside North America occurred in July 2023 in England.
Law
Possible offences
- Possession
- Maximum sentence – 2 years/fine/both
- Possession With Intent To Supply
- Maximum sentence – 14 years/fine/both
- Supply (including being concerned in supply, conspiracy to supply, aggravated supply and offer to supply)
- Maximum sentence – 14 years/fine/both
- Production
- Maximum sentence – 14 years/fine/both
In practice maximum sentences are rarely used, for more detailed and accurate information go to our sentencing page.
