Federal authorities in 2018 temporarily placed all substances related to fentanyl in a category reserved for the most dangerous controlled substances, an effort to stymie drug traffickers. Five years later, the number of overdose deaths linked to synthetic opioids is as high as ever, and critics warn that efforts to make the classification permanent will entrench harsh sentencing laws.
Amid overdose crisis, disputes grow over how to classify fentanyl cousins chron.com - get the latest breaking news, showbiz & celebrity photos, sport news & rumours, viral videos and top stories from chron.com Daily Mail and Mail on Sunday newspapers.
As opioid-related deaths continue to rise in the US, researchers are prohibited from studying the very substances that could provide antidotes to overdose, says chemist Gregory Dudley