evidence: Fentanyl, a powerful painkiller developed nearly 60 years ago, is at the center of the deadliest drug epidemic in American history. More people have died of synthetic-opioid overdoses than the number of U.S. military personnel killed during the Vietnam, Iraq and Afghanistan wars combined. Fentanyl is now the leading cause of death for Americans ages 18 to 49, according to a Washington Post analysis of death data for 2021 from the Centers for Disease Control and Prevention. Why is fentanyl so dangerous? [...] By Julie Hoban and One of the greatest dangers of fentanyl is its potency. Deaths attributed to the drug began to climb in 2013, when traffickers began mixing illicit fentanyl with other drugs including heroin, counterfeit pain pills and cocaine. In some instances, drug users have no idea that fentanyl has been added.