Animal tranquilizer increasingly showing up in New England street drugs

About a third of New England’s illicit drug supply is laced with a potent veterinary tranquilizer called xylazine, often known as “tranq,” according to new data released last week by Brandeis University’s Opioid Policy Research Collaborative.

“It’s a very useful medication when you need to sedate a large animal,” said Traci Green, an epidemiologist who leads the Brandeis project. “Its presence in the drug supply right now, especially in things that are thought to be heroin or fentanyl or pain pills, is an unexpected turn.”

The drug is only approved by the Food and Drug Administration for use in animals. In November, the FDA put out a warning about xylazine exposure in humans, saying it can have “serious and life-threatening side effects.”

While the effects of exposure to xylazine are unpredictable and not fully understood, experts say it can slow someone’s breathing and sedate them for hours at a time. Prolonged use can also worsen withdrawal symptoms and cause severe skin infections that are slow to heal.