SEAN MURPHY, Associated Press

McALESTER, Okla. (AP) — Oklahoma has put to death its first inmate since a botched execution last year prompted the state to rewrite its lethal injection protocols.

Charles Frederick Warner showed no obvious signs of distress Thursday night after the lethal drugs were administered. He was pronounced dead after 18 minutes.

His punishment came just after another inmate was executed in Florida.

Warner’s execution was the second time Oklahoma used the sedative midazolam as part of a three-drug method that had been challenged in appeals as presenting an unconstitutional risk of pain and suffering.

It was first used in the execution of Clayton Lockett, who began writhing on the gurney and trying to lift his head after he’d been declared unconscious.

Among other changes since then, Oklahoma has increased the dose of midazolam.