Nation Fentanyl: 10 questions about the hidden drug that kills people every day April 15, 2019 Georgea Kovanis, Detroit Free Press Comments Off on Fentanyl: 10 questions about the hidden drug that kills people every day Fentanyl is a synthetic opioid and the deadliest drug in America. More than 28,000 of the nation's overdose deaths involved synthetic opioids in 2017.