OKLAHOMA CITY — Oklahoma plans to resume executions Thursday after botching its last one and will use the same three-drug method as a Florida lethal injection scheduled for the same day.

The drug mixture begins with the sedative midazolam and includes the same drugs used in Oklahoma's botched execution of Clayton Lockett, who writhed on the gurney and moaned after he'd been declared unconscious. His execution in April was the first time Oklahoma had used midazolam as the first in a three-drug combination, but attorneys for the state say a failed intravenous line and a lack of training led to the problems with Lockett's lethal injection, not the drugs.

Oklahoma Attorney General Scott Pruitt said the state Department of Corrections "has responded with new protocols that I believe, prayerfully, will provide them more latitude in dealing with exigent circumstances as they arise." His office has successfully defended Oklahoma's new protocol in federal court.

Oklahoma also has increased by five times the amount of midazolam it plans to use to mirror the exact recipe that Florida has used in 11 successful executions.

But midazolam also was used in problematic executions last year in Arizona and Ohio, where inmates snorted and gasped during lethal injections that took longer than expected. Four Oklahoma death row inmates asked the U.S. Supreme Court on Wednesday to halt their executions. They argue that the midazolam won't properly anesthetize them before the second and third drugs are administered, creating a risk of unconstitutional pain and suffering.

"There is a well-established scientific consensus that it cannot maintain a deep, comalike unconsciousness," the inmates' attorneys wrote in a petition with the nation's highest court.

Florida plans to execute Johnny Shane Kormonday, 42, for killing a man during a 1993 home-invasion robbery in Pensacola, while Oklahoma intends to execute Charles Frederick Warner, 47, an hour later Thursday for killing his roommate's infant daughter in 1997 in Oklahoma City.

Pruitt acknowledged that midazolam is not Oklahoma's first choice to be used in lethal injections. But he said state prison officials have been unable to secure other, more effective drugs because the manufacturers oppose their use in executions.

"Pentobarbital is best," the attorney general said. "It's worked in our state, but the manufacturers of pentobarbital will not sell that drug ... to a state for death penalty purposes."

During a three-day hearing last month before a federal judge in Oklahoma City, the Department of Corrections' former top attorney, Michael Oakley, testified that midazolam was selected after he talked to counterparts in other states and conducted his own online research. Oakley also said he reviewed trial testimony from a medical expert who testified about the drug's effectiveness during a legal challenge to its use in executions in Florida.

A state investigation into Lockett's botched execution in Oklahoma last year determined that a single IV line failed and that the drugs were administered locally instead of directly into his bloodstream.

Since then, Oklahoma has ordered new medical equipment such as backup IV lines and an ultrasound machine for finding veins, ordered more training for its staff, and renovated the execution chamber with new audio and video equipment to help the execution team spot potential problems.