A number of states are grappling with the question of whether the lethal injection drug Pavulon, also known as pancuronium bromide, paralyzes a condemned inmate’s muscles in a way that masks horrific pain felt during an execution, a side-effect that experts say could violate of the Eighth Amendment’s ban on cruel and unusual punishment. The Tennessee Supreme Court heard arguments about this issue in a death row case in June 2005 and a similar case is expected to reach the Kentucky Supreme Court soon. In May 2005, a Missouri inmate was given a last minute stay so that the U.S. Supreme Court could review his death penalty procedure case. His claim was denied 5-4, and he was later executed.

Opponents of Pavulon say the drug could render the most widely-used lethal injection proceedure in the U.S. unconstitutional, noting that the paralyzing drug has been banned by the American Veterinary Medical Association for animal euthanasia because it can mask any signs that an anesthetic has failed to work. During the lethal injection process, the first drug administered is an anesthetic that puts an inmate to sleep. Pavulon is the second drug used and it is designed to paralyze the person’s muscle system. The third drug, potassium chloride, stops the heart. A University of Miami study of autopsy toxicology report data in 49 U.S. executions using Pavulon revealed that 21 of those inmates were probably conscious when they received potassium chloride, which meant that Pavulon had masked the ability to determine if there was pain and suffering. (The Tennessean, July 5, 2005). See Methods of Execution.