MIAMI, Oct 29 (Reuters) - Seven Florida death row inmates on Tuesday sued the state, saying a new three-step lethal injection procedure could inflict "cruel and unusual punishment" and called on a court to halt executions until the procedure is reviewed.
Florida is the latest of several states facing a shortage of pentobarbital, a barbiturate that has long been the first of three drugs administered in executions. Supplies of pentobarbital have fallen because its manufacturer has clamped down on sales of the drug for executions, prison officials said.
Florida recently adopted a new lethal injection protocol that uses the sedative midazolam in a drug cocktail designed to induce unconsciousness, paralysis and death by cardiac arrest.
The lawsuit claims that midazolam, commercially known as Versed, is a drug primarily used in the treatment of anxiety, and is not an anesthetic. Its use in lethal injections is experimental.
Under the cocktail of drugs, lawyers for the inmates allege, prisoners remain aware of their surroundings but are unable to speak or move, and they endure extreme pain.
While several states have shifted toward a safer one-drug procedure, the Florida Department of Corrections "has clung to an out-of-date, error-prone, three-drug protocol," according to the lawsuit filed in U.S. District Court in Jacksonville.
"Furthermore, Florida has compounded the risk of inflicting unnecessary pain and suffering -- and violating the constitution -- by adding a new, experimental execution drug to the mix," the lawsuit said.
Earlier this month, Florida prison officials carried out the first execution in the United States using midazolam as one of three drugs in a lethal injection.
The drug was used in the Oct. 15 execution of convicted murderer William Happ. Citing eyewitness accounts of the execution, the inmates' lawyers said Happ appeared to remain conscious for a longer time and made more body movements than prisoners executed under a previous formula.
Misty Cash, a Florida Department of Corrections spokeswoman, said after the execution that Happ did not appear to show any signs of suffering or any unusual reaction.
The lawsuit seeks to stop any executions until the courts thoroughly review the three-drug formula and determine whether it abides by state and federal constitutions.
On Monday, state officials in Ohio said they would administer a combination of two drugs, midazolam and hydromorphone, during an execution scheduled to be carried out next month.
According to the U.S. Food and Drug Administration's database of drugs, midazolam injections are marketed by a number of companies including Fresenius Kabi USA, a unit of German drugmaker Fresenius Kabi AG, and hydromorphone and midazolam are both marketed by Hospira Inc and Akorn.
Fresenius Kabi suspended shipments of another drug, propofol, to a U.S. distributor earlier this year after the German company learned that some of it had been sold to the state of Missouri for executions. Missouri eventually returned the drug.
Four of the seven Florida inmates have a hearing scheduled in Jacksonville federal court on Nov. 6, contending the use of midazolam might violate the U.S. Constitution's ban on "cruel and unusual punishment" by allowing inmates to suffer in their final minutes.