Opvee, an opioid-overdose antidote manufactured by Indivior that was approved in 2023, has in recent weeks been slowly rolling out to law enforcement departments. Unlike Narcan or other overdose antidotes currently on the market, Opvee isn’t a naloxone product. It’s nalmefene, a different opioid antagonist that lasts longer. According to cops, nalmefene works better on fentanyl— despite the fact that it’s never been tested in real-world settings, and naloxone still working just fine.