Just when the overdose crisis couldn’t seem to get much worse, along comes another lethal drug
By Jason Langendorf
At a time when the veterinary medication ivermectin is having a moment in the news cycle as an unproven and dangerous COVID-19 treatment, another drug—xylazine—intended only for use in animals is reportedly playing a role in the rising number of overdose deaths across the U.S.
Xylazine is an animal sedative that has not been approved for use in humans by the Food and Drug Administration (FDA). It was detected in overdose deaths in 25 of 38 states in a recent examination by the Centers for Disease Control and Prevention (CDC), and was listed as the cause of death in 64.3% of those cases. The data appeared last week in the CDC’s Morbidity and Mortality Weekly Report (MMWR).
The detection of xylazine in multiple jurisdictions is concerning and warrants continued surveillance to inform overdose response and prevention efforts given that naloxone administration may not be as effective when xylazine is mixed with opioids.”—Mbabazi Kariisa in “Morbidity and Mortality Weekly Report”
Sometimes added to illicitly produced opioids such as fentanyl and heroin, xylazine can enhance the chemical effects of those already lethal drugs. With muscle relaxant and analgesic properties, xylazine acts as a central nervous system depressant, causing respiratory depression, slowed heart rate and hypotension. And because it isn’t an opioid, xylazine fails to respond to the overdose-reversal medication naloxone.
“The detection of xylazine in multiple jurisdictions is concerning and warrants continued surveillance to inform overdose response and prevention efforts given that naloxone administration may not be as effective when xylazine is mixed with opioids,” writes Mbabazi Kariisa, a researcher in the CDC’s Division of Overdose Protection at the National Center for Injury Prevention and Control, in the MMWR report.
Tracking the Path of Xylazine
Compiling data from the Statewide Unintentional Drug Overdose Reporting System (SUDORS)—a state-by-state OD reporting resource—the CDC identified a total of 531 xylazine-involved deaths during the period from January to December 2019. The drug was detected in another 295 cases but wasn’t determined to be a contributor to the cause of death.
While the number of xylazine-involved deaths makes up a relatively low 1.2% of the total 45,676 overdose fatalities reported to SUDORS during this period, Kariisa writes that the trend “is concerning and warrants continued surveillance to inform overdose response and prevention efforts.”
Additionally, the CDC warns that the number of xylazine-related overdose deaths may actually be larger than its research indicates, due to the potential for missed detection. Xylazine is not part of current testing protocol standards in routine postmortem toxicology panels.