Inclusion in polysubstance use and a spread from the eastern half of the United States to the West—similar to that of fentanyl—emerged as key observations from a report on xylazine released by Millennium Health on Thursday.
The Millennium Health Signals Report, published by the San Diego, California-based organization with more than 15 years of experience in medication monitoring and drug testing services, examined drug use trends in the 100 days following the Biden administration’s emerging drug threat designation.
Millennium Health found that more than 99% of xylazine-positive fentanyl specimens analyzed also contained fentanyl, illustrating the degree to which use of the 2 substances has been intertwined since the Biden administration declared the combo an emerging drug threat in April.
In much the same way fentanyl entered the US in the East and steadily moved west, xylazine is following a similar pattern, the organization said. While xylazine use was detected in 34 states spread across every region of the US during the 100 days following the emerging threat designation, the highest rates of xylazine detection were observed in the Mid-Atlantic and East North Central regions. The lowest rates observed were in the Pacific and Mountain regions.
A prevalence of polysubstance use was also a major theme of the report, with use of multiple substances significantly more frequent among those using fentanyl with xylazine compared to those who used fentanyl but not xylazine. Among users of fentanyl analogues, 56% of samples were also positive for both fentanyl and xylazine compared to 17% of those positive for fentanyl but not xylazine.
“If you’re using fentanyl, you’re very likely using any number of other substances,” Eric Dawson, PharmD, Millennium Health vice president of clinical affairs, told Addiction Professional. “Our own data shows that for fentanyl-positive samples, almost 85% are positive for another substance. … But what was shocking was how much more likely you are to be using another drug if you’re using fentanyl with xylazine.”
Meanwhile, more than 10% of those who used xylazine also tested positive for other sedating substances.