Little-Known Animal Tranquilizer Accelerates US Opioid Epidemic

A little-known animal tranquilizer is accelerating the deadly US opioid epidemic, frustrating health officials and lawmakers, who can’t keep the drug out of people’s hands.

The sedative, called xylazine, was implicated in more than 3,000 overdose-related deaths in the US in 2021, likely an undercount, health officials say. In the same year more than a third of overdose deaths in such heavily affected areas as Philadelphia involved the drug, usually in combination with fentanyl. Regulators are scrambling to track down its source while doctors search for ways to treat affected patients.

Xylazine is dangerous in so many ways: It constricts blood vessels, which can facilitate ...