Why is Everyone Talking About Xylazine?

If you are involved in any kind of drug chemistry or toxicology testing, you are very likely aware of the drug xylazine and its rise to fame as both a recreational drug and adulterant. With the prevalence of xylazine increasing, it is important to have all the information about xylazine and how best to analyze for it.

Known by street name “tranq”, xylazine is a sedative that has both analgesic and muscle relaxant properties.¹ It has been approved by the FDA for veterinary use only.¹ While xylazine is not currently classified as a controlled substance in the United States, it is known to be toxic or even lethal to humans at various levels. Xylazine has been known to be a popular drug of abuse since the early 2000s, and in recent years it has emerged as a popular adulterant for opioids such as heroin or illicit fentanyl. Xylazine and fentanyl drug mixtures can be especially dangerous for drug users, as naloxone (Narcan) cannot reverse the effects of xylazine as it does opioids.¹ The pharmacological effects of xylazine are similar to that of fentanyl and other opioids, causing users to experience sedation, disorientation, drowsiness, and respiratory depression.¹ This means that the combination of xylazine and heroin or fentanyl can increase the potential that a fatal overdose may occur. Because xylazine is often seen as an adulterant in fentanyl or heroin, drug users may unaware it is present in a drug supply.

Figure 1: Chemical Structure of Xylazine

The DEA estimates that xylazine-positive overdose deaths may have increased by more than 1,000% in some regions of the U.S in the past few years.¹ The prevalence of xylazine is likely even higher than this estimate, as xylazine testing is not routinely performed by most toxicology and drug chemistry labs.

It’s unlikely xylazine use will be going away anytime soon, so adding this drug to your laboratory’s testing scope is more important than ever. Xylazine can be easily incorporated into an already existing method, like Restek’s Multiclass Drug “Big Pain” Panel on the Raptor Biphenyl.² By adding xylazine to an already existing panel, you can analyze for this compound alongside other drugs of abuse it is commonly mixed with. In the figure below, a chromatogram was generated by adding xylazine to this LC-MS/MS method which utilizes a 100 x 2.1, 2.7 µm Raptor Biphenyl column. The method parameters are also listed below.

Table 1: Method Parameters for Xylazine on “Big Pain” Panel

 

Figure 2: Chromatogram for Xylazine (@ 4.93 min) on “Big Pain” Panel

 

Table 2: MRM Transition for Xylazine

Peak	TR (min)	Ion Mode	Precursor	Product Ion	Product Ion
Xylazine	4.93	ESI+	220.90	90.15	164.15

Now that you know the basics of xylazine, you can add this analyte to your laboratory’s scope in no time. As more laboratories develop the ability to test for xylazine, a more accurate idea of xylazine prevalence can be established.

References

1. United States. U.S. Drug Enforcement Administration DEA. (2022, October) The Growing Threat of Xylazine and its Mixture with Illicit Drugs. Retrieved from Drug Enforcement Administration Web site: https://www.dea.gov/documents/2022/2022-12/2022-12-21/growing-threat-xylazine-and-its-mixture-illicit-drugs
2. Big Pain Assays Aren’t a Big Pain With the Raptor Biphenyl LC Column. restek.com/articles/big-pain-assays-arent-a-big-pain-with-the-raptor-biphenyl-LC-column