By Heide Brandes and Jon Herskovitz
(Reuters) - Oklahoma does not plan to reveal whether it has abided by the request of a drug maker to return a sedative it uses in its executions that is also at the center of a case before the U.S. Supreme Court, officials said on Friday.
Akorn Inc sent a letter to the Oklahoma Attorney General in March saying the use of its drug midazolam for executions violated U.S. drug protocols and asked the state to return what it had purchased.
Oklahoma officials said the state could not comment due to laws that prohibit discussing the lethal injection drugs.
"Drug manufacturers are being pressured by anti-death penalty activists, making it increasingly difficult for states like Oklahoma to secure the drugs necessary to carry out the lethal injection process," said attorney general's office spokesman Aaron Cooper.
In the case at the Supreme Court, lawyers for three convicted murderers in Oklahoma told justices this week midazolam is unsuitable for use in executions because it cannot achieve the level of unconsciousness required for surgery.
They say using midazolam violates the U.S. Constitution's Eighth Amendment prohibition on cruel and unusual punishment. The state argued the drug is appropriate and necessary given the difficulties it is facing in acquiring lethal injection drugs.
Midazolam has been used in executions in Oklahoma, Florida, Ohio and Arizona.
The Supreme Court decision is expected by the end of June.
In March, Akorn said it was banning sales of midazolam to prison systems and calling on its wholesalers to do the same, saying it strongly objected to the use of its products in capital punishment.
Executions in Oklahoma came under greater scrutiny after the flawed lethal injection a year ago of convicted murderer Clayton Lockett, who received midazolam and was seen twisting on the death chamber gurney after medical staff improperly placed the IV line.
Citing ethical reasons, drugmakers, mostly from Europe, began about four years ago banning sales of drugs for use in executions. States were forced to find new combinations and turned to lightly regulated compounding pharmacies, which can mix chemicals, for their execution drugs.
Another barrier was set up in March when the largest association of U.S. pharmacists approved a measure urging members to avoid participating in executions.
States have been considering alternatives, such as revising the use of firing squads, the electric chair and gas chambers.
(Reporting by Heide Brandes in Oklahoma City and Jon Herskovitz in Austin, Texas; Editing by Doina Chiacu)