Xylazine-laced fentanyl is causing wounds and scrambling efforts to stop overdoses

A powerful animal sedative in the illicit drug supply is complicating the U.S. response to the opioid crisis, scrambling longstanding methods for reversing overdoses and treating addiction.

Xylazine can cause severe skin wounds, but whether it is leading to more deaths — as suggested by officials in Washington — is not yet clear, according to health and law enforcement professionals on the front lines of efforts in New Jersey, New York and Pennsylvania. In fact, early data suggests the drug may inadvertently be diluting the effects of fentanyl, the synthetic opioid behind most overdose deaths.

There is broad agreement, however, that much more information is needed to understand xylazine’s impact, to craft ways of disrupting illegal supplies and to develop medicines to reverse its effects.