Why xylazine, the veterinary drug that federal officials call an "emerging threat," doesn't respond to naloxone

Naloxone, a medication that can reverse opioid overdoses and save the lives of people who use drugs, doesn't work on xylazine, a veterinary tranquilizer that White House officials have labelled an "emerging threat" in the illicit drug supply.  

That's because naloxone — also known by the brand name Narcan — is just not formulated to work on xylazine, which is a powerful sedative, not an opioid. 

Amy Werremeyer, the chair of the department of pharmacy practice at North Dakota State University, told CBS News that expecting naloxone to work on xylazine is akin to putting a star-shaped peg in a round hole.