Sep 14, 2023 - Health

The stark U.S. divide in xylazine use

Rate of xylazine drug test positivity rates in fentanyl-positive specimens
Data: Millennium Health; Graphic: Rahul Mukherjee/Axios

There are stark regional differences in the use of xylazine, a powerful veterinary sedative increasingly mixed with illicit fentanyl that can cause skin-rotting wounds, according to a new report from the drug testing lab Millennium Health.

Why it matters: Fatal overdoses involving xylazine, also known as "tranq" or "zombie drug," have skyrocketed in recent years, worsening the nation's drug crisis. And a patchy surveillance system scattered across local and state governments makes it difficult to track xylazine's spread in real time.

What they found: While virtually all positive urine tests for xylazine also contained fentanyl, 16% of fentanyl-positive tests contained xylazine between April and July, according to Millennium's data.

  • The rates are much higher in some states — 42.8% in Pennsylvania, 40% in North Carolina, and 36.1% in Ohio.
  • It's still largely a regional phenomenon, though Millennium testing detected xylazine in 34 states since the Biden administration in April declared the fentanyl-xylazine combination a threat to the U.S.
  • In Mid-Atlantic states, 40% of fentanyl-positive tests contained xylazine, and it was 33% in East North Central states.
  • Here's how the remaining states broke down, by U.S. Census Division: South Atlantic (22%), East South Central (19%), New England (16%), West NorthCentral (13%), West South Central (5%), Pacific (4%) and Mountain (2%).

The big picture: The DEA late last year noted that xylazine appears to be moving from the Northeast westward, similar to the path fentanyl took.

  • Eric Dawson, vice president of clinical affairs at Millennium Health, said his company's data shows there hasn't yet been a significant geographical shift, but it's something to watch very closely.
  • "You still have this incredibly sharp divide within the country," Dawson said. "It looks like our fentanyl map around 2017, and we know what happened with fentanyl — it moved sharply west."

Of note: Use of multiple drugs was significantly higher among those using fentanyl with xylazine, compared to those using just fentanyl.

  • They were about twice as likely to also use prescription opioids and three times as likely to use fentanyl analogues.
  • They also used at higher rates gabapentin, benzodiazepines, cocaine and methamphetamine. The only exceptions were alcohol and marijuana.
  • "That really speaks to the danger of xylazine. It's being taken with fentanyl and all of these other things, some of which like xylazine won't respond to Narcan," Dawson said, referring to the overdose reversal drug that works just on opioids like fentanyl.
Go deeper