LITTLE ROCK, Ark. (AP) — A federal appeals court on Tuesday upheld Arkansas’ use of the sedative midazolam in its lethal injections.

A three-judge panel of the 8th U.S. Circuit Court of Appeals affirmed a lower court judge’s ruling upholding the state’s execution process. U.S. District Judge Kristine Baker in 2020 ruled that the state’s use of midazolam in injections is constitutional and dismissed claims that less painful methods of execution are available.

“With no scientific consensus and a paucity of reliable scientific evidence concerning the effect of large doses of midazolam on humans, the district court did not clearly err in finding that the prisoners failed to demonstrate that the Arkansas execution protocol is sure or very likely to cause severe pain,” the appeals panel said in its ruling.

The ruling comes more than five years since Arkansas raced to execute eight inmates over 11 days before its batch of midazolam expired. The state ultimately put four men to death after courts halted the other four executions.

The state has not executed any inmates since 2017 and doesn’t have any executions scheduled.

“It is past time that justice be carried out in these cases of defendants killing innocent people, and the Eighth Circuit’s decision reaffirms that Arkansas’ execution protocol is constitutional,” Attorney General Leslie Rutledge, a Republican, said in a statement. “It is time to move forward.”

An attorney for the death row inmates challenging the process did not have an immediate comment on the ruling.

The inmates’ case focused on midazolam, which critics have said doesn’t render inmates fully unconscious before other lethal injection drugs are administered. The U.S. Supreme Court upheld midazolam’s use in executions in 2015, but its use still prompts legal challenges.

Seven states have used the sedative as the first administered in a three-drug execution process, and two have used it in a two-drug process, according to the Death Penalty Information Center.

Critics of midazolam have cited its use in several botched U.S. executions, and Oklahoma put executions on hold in 2015 because of problems. Oklahoma resumed lethal injections last year, and a federal judge in June upheld the state’s execution protocol.

Under Arkansas’ execution process, inmates are first administered midazolam. They’re then administered vecuronium bromide, which stops the lungs, followed by potassium chloride, which stops the heart. Witnesses called by the Arkansas inmates’ attorneys during a 2019 trial before Baker included pharmacologists who said midazolam can start to lose its effectiveness within four to eight minutes of being administered. An anesthesiologist who testified on the state’s behalf, however, described midazolam as an effective sedative.

Attorneys for the inmates said two of the executions Arkansas carried out in 2017 highlighted the problems with midazolam. One execution cited is that of convicted murderer Kenneth Williams, who witnesses said lurched and convulsed 20 times before he died. Another inmate, Marcel Williams, arched his back and breathed heavily during his execution, according to a witness.