Classics in Chemical Neuroscience: Xylazine

Area of Science:

• Veterinary pharmacology
• Toxicology
• Public health

Background:

• Xylazine, a non-opioid veterinary sedative, is increasingly detected as an adulterant in illicit drug supplies.
• Its co-administration with fentanyl is associated with a heightened risk of fatal overdose.
• The prevalence of xylazine in seized drugs has dramatically increased, posing a significant public health challenge.

Purpose of the Study:

• To provide a comprehensive overview of xylazine.
• To outline its synthesis, pharmacokinetics, pharmacodynamics, and adverse effects.
• To discuss its role in the current opioid epidemic.

Main Methods:

• This is a narrative review.
• It synthesizes information from existing literature on xylazine.
• The review covers chemical properties, biological effects, and public health implications.

Main Results:

• Xylazine is a potent veterinary sedative now prevalent as a fentanyl adulterant.
• Overdose deaths involving xylazine have surged by 35 times between 2018 and 2021.
• In 2022, xylazine was found in nearly 25% of seized fentanyl powder.

Conclusions:

• Xylazine represents an emerging drug of abuse and a growing public health threat.
• The combination of xylazine with fentanyl increases the risk of fatal overdoses.
• There is an urgent need to understand and address the impact of xylazine in the context of the opioid crisis.