Gov. John Kasich has put Ohio executions on hold until May, citing a legal challenge to the state's three-drug lethal injection protocol.The governor's office released a statement saying it had postponed the execution dates for the next eight prisoners on death row, including the next prisoner to die, Ronald Phillips, who had his date moved from next Wednesday to May 10.Executions have been on hold in Ohio since Jan. 16, 2014, when the state used a sedative called midazolam during the execution of Dennis McGuire.It took 24 minutes for McGuire to die and he "started struggling and gasping loudly for air, making snorting and choking sounds which lasted for at least 10 minutes," according to a witness.The state had planned to resume using midazolam in a new lethal injection protocol this year, but in January a federal judge rejected the state's three-drug procedure, on the grounds that midazolam is not sufficiently humane in its effects, as we have reported.The drug has also been used during botched executions in Arizona, Oklahoma and Alabama.After five days of hearings, U.S. District Court Magistrate Judge Michael Merz blocked three upcoming executions in a decision issued Thursday morning, writing that the "use of midazolam as the first drug in Ohio's present three-drug protocol will create a 'substantial risk of serious harm' or an 'objectively intolerable risk of harm.' "Merz also wrote that barbiturates offer a potentially preferable alternative to midazolam. Barbiturates such as pentobarbital were the lethal injection drugs of choice until pharmaceutical companies began blocking their sale for executions, as The Two-Way has reported.