For the first time, fentanyl has been used in the execution of a US prisoner. Carey Dean Moore was put to death via lethal injection at the Nebraska State Penitentiary Tuesday morning using a previously untested combination of four drugs: fentanyl citrate, the powerful synthetic opioid blamed for deadly overdoses as the nation struggles with an opioid epidemic; the tranquilizer diazepam; the muscle relaxant cisatracurium besylate; and potassium chloride to stop the heart. "We really don’t know how fentanyl is going to play out in an execution, as opposed to an opioid overdose," a law professor told the New York Times in advance of the execution. "Simply because people are dying as a result of fentanyl doesn’t mean they’re dying in a way that would be considered acceptable as a form of execution."
Moore, 60, was convicted of killing two taxi drivers in 1979, and while he did not seek a last-minute reprieve from his sentence, two pharmaceutical companies did attempt to block the execution, arguing their reputations would be harmed. But prison officials wouldn't identify the suppliers of the drugs, so since the companies couldn't prove their products were being used, the execution—Nebraska's first since 1997—was allowed to proceed. According to USA Today, witnesses reported no apparent complications beyond some coughing by Moore. He reportedly said "I love you" several times before dying. The four-drug cocktail that was used could offer a new execution method to states that are struggling to obtain execution drugs, but the inclusion of fentanyl has raised ethical concerns. (Another execution that planned to use fentanyl was halted in Nevada.)