A sedative that Nevada prison officials plan to use for the first lethal injection in the state since 2006 has been blamed for problems during executions in recent years in several other states.

The U.S. Supreme Court ruled in 2015 that the drug, midazolam, can be used in lethal injections. But the American Civil Liberties Union of Nevada pointed Thursday to Arizona’s decision to stop using it following an execution that took nearly two hours to kill Joseph Rudolph Wood a year earlier.