The Food and Drug Administration (FDA) issued an alert on Tuesday warning health professionals to be “cautious” with an animal drug that has entered the illegal drug supply and has been identified in overdose.
The medicine xylazine, has been approved by the FDA for use as an animal sedative and analgesic. It is not approved for use in humans and can cause “severe and life-threatening side effects that appear to be similar to those commonly associated with opioid use.”
The FDA said that xylazine was most often found in combination with opioids such as fentanyl or heroin, or occasionally together with stimulants such as methamphetamine or cocaine. The administration warned that people who are exposed to xylazine “may not be aware” that it is present in their drug supply.
The alert warned that it can be “difficult to distinguish” xylazine overdoses from opioid overdoses, as some side effects, including respiratory depression, are similar.
Routine toxicology tests also fail to detect xylazine. Others side effects may include hypothermia, hypotension, and “severe necrotic skin ulcerations” caused by repeated exposure to xylazine by injection.
Despite similar side effects and presentation, xylazine affects the human body differently than opioids.
“Xylazine knocks out in a very broad way.a,” said Claire Zagorski, a paramedic and program director and harm reduction instructor for the Texas Opioid Training Initiative at the University of Texas at Austin.
“It slows down brain activity, it slows down your heart rate, it slows down your breathing, but opioids have this special aspect where they can actually stop breathing. Xylazine does not act in the same waya… We’re not seeing the kind of sudden fatal overdose like we’ve been seeing with fentanyl,” he insisted.