Xylazine in the drug supply: Emerging threats and lessons learned in areas with high levels of adulteration

Reported Xylazine Use Among Adults Aged ≥18 Years Evaluated for Substance Use Treatment - United States, July 2022-September 2023

Xylazine has been increasingly detected in illegally manufactured fentanyl (IMF) products and overdose deaths in the United States; most xylazine-involved overdose deaths involve IMF. A convenience sample of U.S. adults aged ≥18 years was identified from those evaluated for substance use treatment during July 2022-September 2023. Data were collected using the Addiction Severity Index-Multimedia Version clinical assessment tool. Among 43,947 adults, 6,415 (14.6%) reported IMF or heroin as their primary lifetime substance-use problem; 5,344 (12.2%) reported recent (i.e., past-30-day) IMF or heroin use. Among adults reporting IMF or heroin as their primary lifetime substance-use problem, 817 (12.7%) reported ever using xylazine. Among adults reporting recent IMF or heroin use, 443 (8.3%) reported recent xylazine use. Among adults reporting IMF or heroin use recently or as their primary lifetime substance-use problem, those reporting xylazine use reported a median of two past nonfatal overdoses from any drug compared with a median of one overdose among those who did not report xylazine use; as well, higher percentages of persons who reported xylazine use reported other recent substance use and polysubstance use. Provision of nonjudgmental care and services, including naloxone, wound care, and linkage to and retention of persons in effective substance use treatment, might reduce harms including overdose among persons reporting xylazine use.

Barriers to, and Facilitators of, Checking Drugs for Adulterants in the Era of Fentanyl and Xylazine: Qualitative Study

BACKGROUND

Overdose deaths continue to reach new records in New York City and nationwide, largely driven by adulterants such as fentanyl and xylazine in the illicit drug supply. Unknowingly consuming adulterated substances dramatically increases risks of overdose and other health problems, especially when individuals consume multiple adulterants and are exposed to a combination of drugs they did not intend to take. Although test strips and more sophisticated devices enable people to check drugs for adulterants including fentanyl and xylazine prior to consumption and are often available free of charge, many people who use drugs decline to use them.

OBJECTIVE

We sought to better understand why people in the New York City area do or do not check drugs before use. We plan to use study findings to inform the development of technology-based interventions to encourage consistent drug checking.

METHODS

In summer 2023, team members who have experience working with people who use drugs conducted 22 semistructured qualitative interviews with a convenience sample of people who reported illicit drug use within the past 90 days. An interview guide examined participants' knowledge of and experience with adulterants including fentanyl, xylazine, and benzodiazepines; using drug testing strips; and whether they had ever received harm reduction services. All interviews were audio recorded, transcribed, and analyzed for emerging themes.

RESULTS

Most participants lacked knowledge of adulterants, and only a few reported regularly checking drugs. Reasons for not checking included lacking convenient access to test supplies, or a place to check samples out of the public's view, as well as time considerations. Some participants also reported a strong belief that they were not at risk from fentanyl, xylazine, or other adulterants because they exclusively used cocaine or crack, or that they were confident the people they bought drugs from would not sell them adulterated substances. Those who did report testing their drugs described positive interactions with harm reduction agency staff.

CONCLUSIONS

New forms of outreach are needed not only to increase people's knowledge of adulterated substances and awareness of the increasing risks they pose but also to encourage people who use drugs to regularly check their substances prior to use. This includes new intervention messages that highlight the importance of drug checking in the context of a rapidly changing and volatile drug supply. This messaging can potentially help normalize drug checking as an easily enacted behavior that benefits public health. To increase effectiveness, messages can be developed with, and outreach can be conducted by, trusted community members including people who use drugs and, potentially, people who sell drugs. Pairing this messaging with access to no-cost drug-checking supplies and equipment may help address the ongoing spiral of increased overdose deaths nationwide.

Empirical assessment of wounds among people who use substances

BACKGROUND

Wounds are a significant source of morbidity among people who use substances (PWUS). This project sought to identify the incidence and severity of wounds among PWUS in the South Bronx, a region of New York City with one of the highest morbidities of substance use disorder.

METHODS

This study recruited PWUS within the past 30 days. Research staff were trained to document the presence and severity of wounds. The primary outcome measure was the incidence of wounds. Acceptability of on-the-street wound care was assessed by the number of participants encountered. The association between participant characteristics and wounds was also evaluated.

RESULTS

In total, 586 PWUS were assessed (19.4 % female: 69 % Hispanic; 23 % Black; 5 % White). Heroin (65.7 %) and psychostimulants (58.3 %) were the most commonly used drugs. Approximately 23 % of outreach recipients disclosed a wound. Among those with a wound, 60.9 % reported one wound, 27.8 % had two wounds, and 11.3 % had three or more wounds. Small wounds (approximately the size of a cherry) were the most common (78.6 %). Recent use of stimulants or heroin, along with intravenous use of any substance were significantly associated with having a wound.

CONCLUSIONS

This study found that drug-related wounds were common among PWUS. Toxicology data from other sources indicate that xylazine was present in the NYC market at the time, though its prevalence among the current sample is difficult to determine. The occurrence and severity of substance-related wounds in NYC should continue to be monitored as a function of changes in the xylazine adulteration.

Pilot findings on the real-world performance of xylazine test strips for drug residue testing and the importance of secondary testing methods

Background

Xylazine is a sedative found increasingly in the illicit fentanyl supply that can cause hypotension, bradycardia, necrosis and death. This pilot examined the real-world performance of BTNX xylazine test strips (XTS) in drug residue samples.

Methods

This study was nested within a drug checking service in Rhode Island. We tested unmeasured drug residue dissolved in 5 mL of distilled water using XTS and Liquid Chromatography Quadrupole Time-of-Flight Mass Spectrometry (LC-QTOF-MS). Analyses compared XTS and LC-QTOF-MS results to calculate XTS detection of xylazine in residue.

Results

Among 41 residue samples, xylazine was detected in 11% by the XTS and 44 % by the laboratory. The LC-QTOF-MS detected xylazine in 18 samples: 4 major, 9 minor, 5 trace by volume relative to the whole sample. The XTS disagreed with the LC-QTOF-MS by indicating a negative result in 77.8 % (N=14) of the samples but never indicated a positive when the LC-QTOF-MS reported xylazine's absence. The XTS correctly detected xylazine 22 % of the time, however, this increased to 100 % of the time if xylazine was a major active component.

Conclusions

In this study, the BTNX XTS often disagreed with LC-QTOF-MS by indicating a negative result, likely due to the dilution levels used and sample composition. The XTS may not be accurate in detecting residual amounts of xylazine, especially if xylazine is not a dominant component of the tested sample. Given the novelty of BTNX's XTS products, we recommend XTS only be used in conjunction with other advanced drug checking modalities for residue testing.

Co-administration of naloxone and dexmedetomidine to simultaneously reverse acute effects of fentanyl and methamphetamine in rats

BACKGROUND

The incidence of combination methamphetamine (METH)-opioid overdose has substantially increased in recent years. While agitation is uncommon after the naloxone (NLX) reversal of opioids, it is a major clinical concern in acute METH intoxication and can be physiologically antagonized by opioid-induced sedation. This study aimed to perform initial preclinical analysis of the safety and efficacy of dexmedetomidine (DEXMED) co-administered with NLX to attenuate METH-induced locomotor activity, as a rat model of agitation, after the reversal of fentanyl (FENT)-induced sedation.

METHODS

Male Sprague Dawley rats were administered subcutaneous (SC) 0.1mg/kg FENT ± 1mg/kg METH. Fifteen min later, SC 0.1mg/kg NLX ± an increasing (0, 0.032, 0.056, and 0.1mg/kg) DEXMED dose was administered prior to the measurement of locomotor activity. After a washout period, the FENT ± METH and NLX ± DEXMED administration with the highest dose of DEXMED was administered for measurement of blood oxygen saturation and heart rate.

RESULTS

After the NLX reversal of FENT-induced sedation, adjunct DEXMED substantially and significantly reduced METH-induced locomotor activity (p<0.05) at all doses tested. While the addition of DEXMED did not significantly reduce blood oxygenation in METH treated rats, it did so in the absence of METH. Also, DEXMED significantly reduced heart rate compared to non-DEXMED treated groups and resulted in further significant reductions in the animals not exposed to METH (p<0.05).

CONCLUSIONS

These data provide preclinical evidence that DEXMED may be a safe and effective chemical restraint for METH-induced agitation after NLX opioid reversal.

A qualitative study on perceptions and experiences of overdose among people who smoke drugs in Vancouver, British Columbia

BACKGROUND

Smoking unregulated drugs has increased substantially in British Columbia. Intersecting with the ongoing overdose crisis, drug smoking-related overdose fatalities have correspondingly surged. However, little is known about the experiences of overdose among people who smoke drugs accessing the toxic drug supply. This study explores perceptions and experiences of overdose among people who smoke drugs.

METHODS

We conducted interviews with 31 people who smoke drugs. Interviews covered a range of topics including overdose experience. Thematic analysis was used to identify themes related to participant perceptions and experiences of smoking-related overdose.

RESULTS

Some participants perceived smoking drugs to pose lower overdose risk relative to injecting drugs. Participants reported smoking-related overdose experiences, including from underestimating the potency of drugs, the cross-contamination of stimulants with opioids, and responding to smoking-related overdose events.

CONCLUSIONS

Findings highlight the impact the unpredictable, unregulated, and toxic drug supply is having on people who smoke drugs, both among people who use opioids, and among those who primarily use stimulants. Efforts to address smoking-related overdose could benefit from expanding supervised smoking sites, working with people who use drugs to disseminate accurate knowledge around smoking-related overdose risk, and offering a smokable alternative to the unpredictable drug supply.

"It gets you high as a kite but not unsick": Characterizations of and responses to a changing local drug supply by people who use drugs in Rhode Island

BACKGROUND

The North American overdose crisis has continued at unprecedented rates with more than 100,000 overdose deaths occurring in the United States (US) in 2022. Overdose deaths have increasingly been polysubstance-involved, with novel substances (e.g., xylazine) complicating overdose risk and health outcomes. Understanding the effects of-and responses to-a changing drug supply among people who use drugs is critical to modifying harm reduction strategies to be more responsive to people's needs.

METHODS

This qualitative study draws on data collected from May to December 2022 in Rhode Island. Data include in-depth interviews with 50 people who use drugs and observational fieldwork in spaces frequented by participants (e.g., encampments, drop-in centers). Qualitative data were analyzed thematically drawing on concepts of situated rationality.

RESULTS

Participants described significant changes in the drug supply, with many attributing these transitions to COVID-19. Most participants characterized the local supply as "synthetic" with textures, color, and taste evolving. Notably, participants emphasized adverse outcomes related to available supplies, including during use (e.g., intense burning sensations) and post-consumption (e.g., heavy sedation, ongoing withdrawal, necrosis). Given the complex supply, participants highlighted the increased risk of overdose and shared how they altered their use practices to manage evolving health risks.

CONCLUSION

Our results underscore how people who use drugs characterized the local drug supply, including perceived changes to supply contents. Implementing and scaling up harm reduction interventions that reduce risk and reinforce the agency of people who use drugs are urgently needed to effectively address the overdose crisis.

Reported xylazine exposure highly associated with overdose outcomes in a rapid community assessment among people who inject drugs in Baltimore

BACKGROUND

Addressing xylazine harms are now a critical harm reduction priority, but relatively little epidemiological information exists to determine prevalence, magnitude, and correlates of xylazine use or related outcomes.

METHODS

We conducted a rapid behavioral survey among people who inject drugs (n = 96) in Baltimore November-December 2022. Using a novel indicator of self-reported presumed xylazine effects, we examined prevalence and sociodemographic correlates of past year presumed xylazine effects and association with overdose and wound-related outcomes. Chi-square and descriptive statistics were used to examine bivariate associations overall and separately for those who reported xylazine by name and by reported fentanyl use frequency.

RESULTS

Almost two-thirds (61.5%) reported experiencing xylazine effects. There were no differences by socio-demographics, but xylazine effects were more commonly reported among those who reported injecting alone (66% vs 38%%, p < 0.007) and daily fentanyl use (47% vs 24% p < 0.003). Those reporting xylazine exposure was three times as likely to report overdose (32% vs 11%, p < 0.03) and twice as likely to have used naloxone (78% vs 46%, p < 0.003). They also more commonly reported knowing someone who died of an overdose (92% vs 76%, p < 0.09) and to report an abscess requiring medical attention (36% vs 19%, p < 0.80). These associations were higher among respondents who specifically named xylazine and those who used fentanyl more frequently, but fentanyl frequency did not fully explain the heightened associations with xylazine effects.

CONCLUSIONS

This study provides insight into the scope of xylazine exposure and associated health concerns among community-based PWID and suggests measures that may be instrumental for urgently needed research.

Xylazine in Overdose Deaths and Forensic Drug Reports in US States, 2019-2022

Importance

Xylazine is increasingly reported in street drugs and fatal overdoses in the US, yet state-level data are limited, hampering local public health responses.

Objective

To gather available state-level data on xylazine involvement in overdose deaths and in forensic drug reports.

Design, Setting, and Participants

This cross-sectional study was a secondary analysis of 2019 to 2022 data from the National Forensic Laboratory Information System (NFLIS), National Center for Health Statistics, and individual states' medical examiner or public health agency reports. Data were analyzed from August to October 2023.

Exposure

State.

Main Outcomes and Measures

Yearly xylazine-related overdose deaths per 100 000 residents; xylazine NFLIS drug reports, both per 100 000 residents and as a percentage of all NFLIS drug reports (from samples of drugs seized by law enforcement and analyzed by NFLIS-participating laboratories).

Results

A total of 63 state-years were included in analyses of mortality rates, while 204 state-years were included in analyses of NFLIS reports. According to the publicly available data compiled in this study, at least 43 states reported at least 1 xylazine-related overdose death from 2019 to 2022, yet yearly totals of xylazine-related deaths were available for only 21 states. Of states with data available, xylazine-involved overdose death rates were highest in Vermont (10.5 per 100 000 residents) and Connecticut (9.8 per 100 000 residents) in 2022. In 2019, 16 states had zero xylazine reports included in NFLIS reports; in 2022, only 2 states had zero xylazine reports and all but 3 states had recorded an increase in xylazine's representation in NFLIS reports. In 2022, xylazine represented 16.17% of all NFLIS reports in Delaware and between 5.95% and 7.00% of NFLIS reports in Connecticut, Maryland, District of Columbia, New Jersey, and Rhode Island, yet less than 1.0% of NFLIS reports in 35 different states.

Conclusions and Relevance

In this cross-sectional study of publicly available data on fatal overdoses and drugs analyzed by forensic laboratories, xylazine's reported presence in overdose deaths and forensic reports was concentrated in the eastern US yet extended across the country to encompass nearly all states. In spite of xylazine's geographic reach, yearly state-level numbers of xylazine-related overdose deaths were publicly available for less than half of all states.

Fentanyl Exposure and Detection Strategies Utilized by Clinical Trial Participants Seeking Linkage to Opioid Use Disorder Treatment at a Syringe Service Program

INTRODUCTION

The USA continues to face a fentanyl-driven overdose epidemic. Prior research has demonstrated users of illicit opioids are concerned about fentanyl exposure and overdose, but the strategies they report using to detect fentanyl's presence lack empirical support. This study compares self-report and biologically detected fentanyl use and investigates overdose risk and risk reduction behaviors among a sample of high-risk people who use opioids.

METHODS

Structured enrollment interviews conducted as part of a larger clinical trial assessed self-reported fentanyl exposure as well as strategies used to determine believed fentanyl exposure and prevent overdose among 240 participants enrolled at a Chicago, IL syringe service program. Urinalysis measured actual fentanyl exposure.

RESULTS

Most participants identified as African American (66.7%) and had considerable overdose experience (76.7% lifetime and 48% in the past year). Most also tested positive for fentanyl (93.75%) despite reporting no past year use of fentanyl or fentanyl-adulterated drugs (64.17%). The most utilized approaches reported for identifying fentanyl exposure were stronger effects of the drug (60.7%), sight or taste (46.9%), and being told by someone using the same drugs (34.2%). Few participants (14%) reported using fentanyl test strips. No significant associations were identified between self-report and urinalysis measures or urinalysis results and risk reduction strategies.

CONCLUSION

This study adds to prior fentanyl exposure risk research. The disconnect between participants' fentanyl detection methods and reported overdose experiences supports the need for more research to identify and understand factors driving access and use of overdose prevention resources and strategies.

Xylazine in Drug Seizure Reports and Overdose Deaths in the US, 2018-2022

Xylazine is increasingly reported in street drugs and fatal overdoses in the United States (US), often in combination with synthetic opioids, yet state-level xylazine data are limited, hampering local public health responses. The present study analyzed 2018-2022 state-level data from the National Forensic Laboratory Information System (xylazine-positive reports of seized drugs analyzed by forensic laboratories), the Centers for Disease Control and Prevention (population estimates, synthetic opioid overdose mortality rates), and individual states' medical examiner/public health agency reports (numbers of xylazine-involved overdose deaths). An ordinary least squares regression model predicted state-level synthetic opioid overdose mortality rates by xylazine seizure report rates, adjusting for US Census Region. In 2018, relatively low rates of xylazine seizure reports were observed, with 21 states reporting zero xylazine seizures. In 2022, only three states reported zero xylazine seizures, and the highest xylazine seizure report rates (per 100,000 residents) were observed in New Jersey (30.4), Rhode Island (22.7), Maryland (18.9), Virginia (15.5), New Hampshire (13.0), and Ohio (10.9). Data on 2019-2022 xylazine-involved overdose deaths were available for 21 states/DC (60 state-years), with the highest 2022 xylazine-involved overdose death rates (per 100,000 residents) in Vermont (10.5) and Connecticut (9.8). Finally, in 2021, at the state level, each additional reported xylazine seizure per 100,000 residents was associated with a 2% higher synthetic opioid overdose mortality rate (b=0.02, robust standard error=0.01; p=0.049). Overall, study results emphasize xylazine's increasing involvement in US law enforcement drug seizure reports and overdose deaths, primarily in the East, yet also extending across the country.