Prison bosses in Ohio want to use flumazenil for cases when executioners fear the first of three lethal injections has failed to render a prisoner unconscious.
The drug would counteract the sedative midazolam, which has been linked to several botched executions that have seen prisoners left convulsing and writhing in agony before dying of a heart attack.
The sedative is the first drug administered in Ohio’s three-drug execution system.
Gary Mohr, director of the Department of Rehabilitation and Correction, told a federal court earlier this month that he would apply for a reprieve in the event of an aborted execution where the prisoner needed to be resuscitated.
Describing the language he would use in the event of the sedative not working, Mr Mohr told the federal court: “Governor, I am not confident that we, in fact, can achieve a successful execution. I want to reverse the effects of this.”
Magistrate Judge Michael Merz is considering whether the new three-drug execution method is constitutional.
Executions have been on hold in Ohio since January 2014, after prisoner Dennis McGuire fought for breath and repeatedly snorted during the 26 minutes it took for him to die.
McGuire, 53, was sentenced to death for the 1989 rape and murder of 22-year-old Joy Stewart, who was pregnant.
He endured the longest execution since the state resumed putting prisoners to death in 1999.
At the time the state used a two-drug method, starting with midazolam.
It was the first time the drug was used in executions in the US.
In another incident in 2014, prisoner Clayton Lockett took 43 minutes to die after being administered midazolam in the state of Oklahoma.
Lawyers challenging the method say midazolam is unlikely to relieve an inmate’s pain.
Ohio state lawyers, however, say the three-drug method is similar to its past execution process, which has survived repeated court challenges.
They say a Supreme Court ruling last year makes clear the use of midazolam is legal.
Ohio is due to put Ronald Phillips, a condemned child rapist and murderer, to death next month with midazolam and two other drugs.
Jonthan Groner, a Columbus surgeon and lethal injection expert, said problems with previous Ohio executions came about because executioners did not connect the intravenous lines properly.
“A reversal drug will not help with that problem and could make it worse if the IV is not in the vein, giving more drugs may cause more pain,” he said.