Amid a shortage in one of the drugs typically used in death penalty executions, the state of Oklahoma is fighting for the right to execute death row inmates with a drug used to put down animals, reports The Wall Street Journal.

Attorneys for John David Duty, an Oklahoma death row inmate who's scheduled to be executed in December, have filed court documents calling the state's plan potentially painful and torturous.

But that's not how Oklahoma officials see it.

Officials for the state argue that pentobarbital, the drug used in animal euthanasia, is "substantially" similar to thiopental sodium, a drug used by many states to carry out capital punishment. Thiopental is currently unavailable and its sole manufacturer says the earliest doses might not be available until January 2011.

Thiopental sodium does not actually kill inmates, but is an anesthetic and the first of a three-part lethal injection cocktail that serves to sedate inmates so that two other drugs, vecuronium bromide and potassium chloride, can paralyze inmates and then stop their hearts.

Court documents filed by Duty's lawyer say that pentobarbital takes longer to take effect than sodium thiopental and could mean that Duty is not "fully anesthetized" at the time the other drugs are administered, "thereby increasing the risk of suffering excruciating pain."

A federal judge will decide next week if Oklahoma can execute Duty with the drug used on animals.