"We understand that one or more Departments of Correction in the U.S. are considering amend[ing] their lethal injection protocols to include propofol. Clearly, such use is contrary to the FDA approved indications for propofol and inconsistent with Fresenius Kabi's mission of 'caring for life," Scott Meacham, president of Fresenius Kabi's pharmaceutical division in North America, said in a letter to health care providers.
"To best prevent propofol from being used for purposes other than its approved indications, Fresenius Kabi does not accept orders for propofol from any departments of corrections in the U.S.," Meacham said in the letter.
Whether propofol can be used in lethal injections is at the center of Missouri's legal battle.
"That is why the inmates in Missouri are suing," Dieter said. "In order for the drug to be lethal, it needs to be administered in amounts that are much larger than normal. We don't know the side effects of the drug when it's taken in these amounts.
"Given that in the clinical setting, and at normal dosages, many patients experience significant pain on administration of propofol, it is highly likely that the incidence and severity of pain experienced by the prisoners subjected to the massive dose, specified by this protocol would be at least as high as are seen in smaller doses," the lawsuit states.
This pain, according to the lawsuit, constitutes cruel and unusual punishment.
The lawyers representing the death row inmates did not return several calls from ABC News seeking comment.
The Missouri Attorney General's Office countered the lawsuit with a motion to dismiss.
"Pain that is an 'inescapable consequence of death' does not meet the standard to fall under cruel and unusual punishment," Koster wrote.
Missouri is one in a number of states, including California, Maryland, Ohio and Texas, where inmates have sued to change lethal injection protocol.
"In California and Maryland, all executions were halted until the legal proceedings had concluded," Dieter told ABC News. "In Ohio and Texas, the executions were carried on."
For Koster, the inmates' lawsuit against Missouri is a way of stalling the inevitable.
The lawsuit, he said in his recent statement, "has been used by convicted killers as a delay tactic to prevent the state from carrying out lawful judgments."