What are nitazenes? What to know about the drug that can be "10 times as potent as fentanyl"

A Colorado overdose death has been linked to a new formulation of nitazenes, a class of powerful opioid analgesics being increasingly seen in the illicit drug market. 

Nitazenes have been around for decades, experts told CBS News, and have been seen in multiple formulations. The person who died in Colorado had used a formulation called N-Desethyl etonitazene. The man died in mid-2023, Denver officials said, but laboratory testing about the substance he overdosed on was not returned until recently.  

It's believed to be the first time that formulation was found in an overdose death, according to the Boulder County Coroner's office.