(99) Xylazine Usage and Awareness among People who use Drugs in Denver, Colorado

Background & Introduction: Xylazine (aka "tranq") is an alpha-2 agonist with various effects including central nervous system and respiratory depression, analgesia, and blood pressure changes. Skin necrosis is a possible complication of xylazine usage, which can lead to limb amputation. Xylazine is not reversed by naloxone, complicating the treatment for xylazine overdose. Due to the sedative properties of xylazine, its use in facilitated sexual assault and crime has been noted. Xylazine has become increasingly present in the drug supply in the United States, most notably on the East Coast. As of 2023, xylazine presence has been reported in 48 states. However, data regarding xylazine prevalence in Colorado and the Denver Metro area is limited. Additionally, health care facilities often lack the proper resources and training to recognize and respond to xylazine intoxication. The objective of this study was to understand xylazine awareness and usage among people who use drugs in the Denver Metro Area with the goal of improving harm reduction initiatives.

Methods: This project was done in collaboration with the Harm Reduction Action Center in Denver, a public health agency that works with people who use drugs. An IRB-exempt anonymous 16-question survey was conducted among its participants (n=148) from July to August 2023. The survey was administered on paper and took 5-10 minutes to complete. Participants were given candy for completing the survey. Survey questions included: demographic information; drug of choice; route of drug administration; awareness of xylazine; usage of xylazine; whether use was intentional; and xylazine testing strip utilization. Responses that were contradictory or blank were excluded from analysis. A chi-square test was performed to determine the level of significance between the four most selected drugs of choice (fentanyl, heroin, methamphetamine, and THC) and xylazine usage. For this analysis, responses “yes” and “unsure” to the question “have you ever used xylazine” were combined to compare against those that responded “no”. This was done to analyze the significance of those who had never used xylazine compared to those who had used xylazine or were unsure.

Results: Out of 148 participants, 53% had heard of xylazine, 42.1% had not, and 4.8% were unsure if they had. Xylazine use was reported by 16.3% of participants, while 66% had not used xylazine, and 17.7% were unsure Out of the participants that said they had used or were unsure if they had used xylazine (n= 37), 75.7% said it was unintentional use. Eighty-three percent of participants reported they had never used xylazine testing strips while only 14% said they had. None (0%) selected xylazine as their primary drug of choice. The four most selected primary drugs of choice were fentanyl, heroin, methamphetamine, and THC. Those who selected fentanyl or heroin as their primary drug of choice were significantly more likely to have used xylazine (p=0.0002 and p= 0.0125 respectively) while those that selected methamphetamine or THC as their primary drug of choice were significantly less likely to have used xylazine (p=0.9906 and p=0.9997 respectively).

Conclusion & Discussion: This study found that awareness of xylazine is limited despite its presence in the Denver Metro Area. Participants who selected heroin or fentanyl as their primary drug were more likely to have used xylazine, which is consistent with several other studies, including Holt et al 2023. Additionally, most participants reported their xylazine usage as unintentional. Limitations of this study included its self-reported nature, intoxication of participants and minimal usage of xylazine testing strips. Future research is warranted to develop more accurate testing for xylazine intoxication (i.e. blood or urine analysis), to obtain pharmacokinetic data, and to assess clinician knowledge about xylazine. Raising awareness about xylazine and its effects will be pivotal in not only helping people who use drugs make informed medical choices but also in reducing the rates of overdose, sexual assault, and other drug related tragedies in the community.

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