MONTGOMERY, Ala. — The Alabama Supreme Court has set execution dates for two inmates who will be the first put to death with the state's new lethal-injection-drug combination.

The Supreme Court set a Feb. 19 execution date for Tommy Arthur, who was convicted of the 1982 murder-for-hire of a Muscle Shoals man. The court set a March 19 execution date for Bill Kuenzel, who was convicted in the 1987 murder of a convenience store clerk in Sylacauga.

They will be Alabama's first executions since 2013; a shortage of execution drugs left the state unable to carry out death sentences in 2014. The Alabama Department of Corrections in September announced it was turning to a new three-drug combination.

Lawyers for the state said Alabama's new drug combination is similar to that used by Florida to execute multiple inmates. Arthur's attorneys are challenging the method as cruel and unusual punishment, noting it uses a drug used in executions in Arizona, Ohio and Oklahoma in which inmates gasped, writhed or groaned and took longer than expected to die.

The new drug protocol calls for the sequential injections of 500 milligrams of midazolam hydrochloride, a sedative; 600 milligrams of rocuronium bromide, a neuromuscular blocking agent that stops breathing; and 240 "milliequivalents" of potassium chloride to stop the heart.

Lawyers for Arthur said midazolam hydrochloride is unreliable as a sedative and that the inmate would feel the effects of the two drugs administered after it.

"The administration of potassium chloride to an inadequately anesthetized inmate will cause excruciating pain and suffering," Arthur's lawyer, Suhana S. Han, wrote in a court filing earlier this year.

Arthur had a pending federal lawsuit challenging the state's previous death-penalty protocol that used pentobarbital as a sedative followed by injections of pancuronium bromide and potassium chloride. His lawyers have asked a judge to let him amend that lawsuit to challenge the state's new drug combination. A federal judge has not ruled on that request.

The Alabama attorney general's office argued there was no proof the inmates suffered and called Arthur's federal claims part of a long pattern of trying to delay his execution by repeatedly challenging the execution method.

"More importantly no court or independent body has found that any of those executed inmates suffered pain. It appears that the symptoms described in the media reports were conditions associated with sleeping or sleep apnea," lawyers for the state wrote in a filing to the Supreme Court.

Two states, Florida and Oklahoma, have used midazolam as the first drug in a three-drug protocol, according to the Death Penalty Information Center. Ohio and Arizona have used midazolam in a two-drug protocol.

Kuenzel was convicted of killing clerk Linda Offord at Joe Bob's convenience store. Kuenzel's attorneys had unsuccessfully argued that newly discovered evidence raised doubts about his guilt.

"Counsel is unaware of another case involving a compelling claim of innocence and incontestable constitutional error where the litigant failed to receive any opportunity for post-conviction merits consideration," his attorney wrote.

Co-defendant Harvey Venn testified against Kuenzel at trial after taking a plea deal. Venn testified that after driving around, Kuenzel decided to rob the convenience store. He testified that Kuenzel went into the store and he heard a shotgun blast and saw the clerk thrown back, according to court filings.

Kuenzel's lawyers claim Venn, who had blood on his clothes, had a shotgun of the same gauge as the murder weapon and initially told police that he had been at the convenience store with another friend, not Kuenzel.

The attorney general's office is also seeking execution dates for seven other inmates.