Xylazine

Page last updated January 5, 2024 by Doug McVay, Editor.

1. Growth in Reports of Xylazine in the US 2019-2022

"In 2019, relatively low rates of xylazine NFLIS [National Forensic Laboratory Information System] reports were observed; all states had a rate below 6 xylazine NFLIS reports per 100,000 residents, and 16 states had zero NFLIS xylazine reports (Figure 1; eTable 4 in Supplement 1). In contrast, in 2022, only 2 states had zero xylazine NFLIS drug reports, and the highest rates of xylazine NFLIS reports (per 100,000 residents) were observed in New Jersey (30.52), Rhode Island (22.82), Maryland (18.91), Virginia (15.47), New Hampshire (13.10), and Ohio (10.87). In 2019, xylazine NFLIS reports were limited to a few northeastern states; by 2022, xylazine NFLIS reports were still concentrated in northeastern states yet had extended to states south and west.

"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, DC, New Jersey, and Rhode Island, yet less than 1.00% of NFLIS reports in 35 different states (Figure 2; eTable 5 in Supplement 1). Delaware, Maryland, Rhode Island, New Jersey, Connecticut, DC, and Virginia had the highest absolute change in xylazine reports as a percentage of all NFLIS drug reports (2019-2022), while Virginia, Maryland, North Carolina, Michigan, Kansas, Alabama, Minnesota, and Tennessee had the highest relative change. Only 1 state, Wisconsin, recorded a decrease in xylazine’s representation in NFLIS drug reports from 2019 (0.56% of drug reports) to 2022 (0.48% of drug reports), and 2 states reported no increase (0% in 2019 to 0% in 2022; South Dakota and Wyoming) yet in 30 states, across all regions, xylazine reports (as a percentage of all NFLIS drug reports) more than doubled."

Cano M, Daniulaityte R, Marsiglia F. Xylazine in Overdose Deaths and Forensic Drug Reports in US States, 2019-2022. JAMA Netw Open. 2024;7(1):e2350630. doi:10.1001/jamanetworkopen.2023.50630


 

2. Xylazine-Involved Deaths

"Xylazine, an alpha-2 receptor agonist, is used in veterinary medicine as a sedative and muscle relaxant; it is not approved for use in humans. However, reports of adulteration of illicit opioids with xylazine have been increasing in the United States (13). In humans, xylazine can cause respiratory depression, bradycardia, and hypotension (4). Typical doses of naloxone are not expected to reverse the effects of xylazine; therefore, persons who use xylazine-adulterated opioids are at high-risk for fatal overdose. Although some regions of the United States have reported increases in xylazine-involved deaths, xylazine was involved in <2% of overdose deaths nationally in 2019 (2,5). Most xylazine-involved deaths are associated with fentanyls, including fentanyl analogs (1,5)."

Chhabra, N., Mir, M., Hua, M. J., Berg, S., Nowinski-Konchak, J., Aks, S., Arunkumar, P., & Hinami, K. (2022). Notes From the Field: Xylazine-Related Deaths - Cook County, Illinois, 2017-2021. MMWR. Morbidity and mortality weekly report, 71(13), 503–504. doi.org/10.15585/mmwr.mm7113a3

3. Xylazine-Involved and Xylazine-Associated Deaths in Cook County, IL

"A xylazine-associated death was defined as a positive postmortem xylazine serum toxicology test result in an unintentional, undetermined, or pending intent substance-related death during January 2017–October 2021. Routine postmortem tests were conducted for other substances including fentanyl, fentanyl analogs, cocaine, and naloxone. Xylazine testing is standard in Cook County for suspected drug overdose deaths. This activity was reviewed by CDC and was conducted consistent with applicable federal law and CDC policy.*

"A total of 236 xylazine-associated deaths were reported during the study period. Xylazine-associated deaths increased throughout the study period; incidence peaked during July 2021 (Figure). The percentage of fentanyl-associated deaths involving xylazine also increased throughout the study period, rising to a peak of 11.4% of fentanyl-related deaths assessed by the Cook County Medical Examiner’s Office during October 2021. Fentanyl or fentanyl analogs were detected on forensic testing in most xylazine-involved deaths (99.2%). Other common co-occurring substances included diphenhydramine (79.7%), cocaine (41.1%), and quinine (37.3%). Naloxone was detected in 32.2% of xylazine-associated deaths."

Chhabra, N., Mir, M., Hua, M. J., Berg, S., Nowinski-Konchak, J., Aks, S., Arunkumar, P., & Hinami, K. (2022). Notes From the Field: Xylazine-Related Deaths - Cook County, Illinois, 2017-2021. MMWR. Morbidity and mortality weekly report, 71(13), 503–504. doi.org/10.15585/mmwr.mm7113a3