Facing a shortage of supplies for lethal injections, US law enforcement officials have begun executing prisoners with an animal anesthetic that has not been approved at the federal level, with the first such execution coming this week.

European pharmacies, citing a moral issue with capital punishment, have stopped sending certain drugs to regions of the US that still carry out the death penalty, areas that include Ohio, Missouri, Texas, Georgia, Florida, and Arizona.

States are still using pentobarbital, intended to euthanize animals, while local supplies last but those without that option have begun “making changes in their lethal injection process,” Richard Dieter, director of the Death Penalty Information Center, told Agence France Presse.

Missouri had planned to use propofol - the common anesthetic that killed pop star Michael Jackson - for an October execution, but concerns about access to the drug via its German manufacturer Fresenius Kabi led to a reconsideration by state Gov. Jay Nixon on Friday.

"This is a decision that will be welcomed by the medical community and patients nationwide who were deeply concerned about the potential of a drug shortage," John Ducker, CEO of Fresenius Kabi USA, told the Associated Press.



Propofol is used about 50 million times annually in the US, according to the company.



“This is a continuing theme: every time a state starts to use a new drug, the company that makes that drug stops selling it,” said Deborah Denno, a law professor at Fordham University and expert on the subject.

Compounding pharmacies, which create specialized pharmaceutical product meant to fit the needs of a patient, have begun producing the drugs for state authorities.

But because of the lack of transparency around the production process – one compounding pharmacy was responsible for a fatal meningitis outbreak in 2012 because of poor hygiene – prisoners argue that risky drug cocktails put them at risk of being subjected to “cruel and unusual punishment,” which is prohibited under the US Constitution.

Earlier this month three Texas-based death row prisoners filed a lawsuit arguing this type of pharmacy is "not subject to stringent FDA regulations" and is "one of the leading sources for counterfeit drugs entering the US," the lawsuit reads, as quoted by AFP.

"There is a significant chance that [the pentobarbital] could be contaminated, creating a grave likelihood that the lethal injection process could be extremely painful, or harm or handicap plaintiffs without actually killing them," it adds.

“Nobody really knows the quality of the drugs, because of the lack of oversight,” Denno told AFP.

Michael Yowell, who was convicted of murdering his parents 15 years ago, was executed in Texas Wednesday. He became the first inmate to be executed in Texas with pentobarbital since European nations halted production for this purpose. His lawyers unsuccessfully tried to stop him from being killed, saying the compounded factors in pentobarbital make the drug unpredictable and there have not been enough trials to guarantee the death is painless.

The states in question may find an applicable replacement for the short-term but, Denno argued, this development could be an indication that capital punishment is on the wane.

“How many times in this country can they change the way they execute?” she said. “There were more changes in lethal injections in the last 5 years than in the 25 preceding years.”