The state's supply of sodium thiopental, one of three drugs used in lethal injections, was turned over to the federal government in 2011 over questions about how it was imported. The short supply of sodium thiopental in the U.S. has led many states with the death penalty to seek out other drugs.
Arizona, Idaho and Ohio already have carried out executions using a single drug, pentobarbital. However, Tennessee officials are staying tight-lipped about their search for alternative drugs.
The Department of Correction spokeswoman said last week that no decision has been made on revisions to Tennessee's current three-drug method.
"The Department of Correction has been monitoring the steps being taken by other states concerning implementation of lethal injection," department spokeswoman Dorinda Carter said in a response to questions from The Associated Press regarding the search for new drugs.
The department declined a request from the Associated Press to interview Correction Commissioner Derrick Schofield.
He told The Tennessean this month that the state's lethal injection protocol is a top priority and that he is pursuing alternative drugs. But he wouldn't say which drugs are being considered or when a decision may be reached.
In addition to the shortage of sodium thiopental, records obtained by The Associated Press through an open records request indicate that Tennessee has also been unable to get pancuronium bromide, a strong muscle relaxant given to the inmate before the final injection of potassium chloride, which stops the heart.
A memo dated February 2012 stated that the pharmaceutical distributor Morris & Dickson informed the state that pancuronium bromide was recalled in May 2010 and will not be reissued. Carter confirmed last week the state has no supplies of either sodium thiopental or pancuronium bromide.
The FDA drug shortage list indicates that Hospira, which makes pancuronium bromide, says the drug would be available in the first quarter of 2013.
This has essentially stalled any executions in Tennessee. The last inmate executed by lethal injection in the state was Cecil Johnson, on Dec. 2, 2009, and the Tennessee Attorney General's office has not asked the state Supreme Court to set an execution date since 2010. Tennessee has 83 inmates on death row.
The attorney general won't pursue execution dates until officials are ready to proceed with executions, said office spokeswoman Leigh Ann Apple Jones.
Death penalty experts say that whenever the state makes its decision, legal challenges to the revised protocol are likely to occur.
The last major revision to the state's execution protocols came in 2007, when then-Gov. Phil Bredesen issued an executive order to review the policies and procedures and ordered a moratorium on executions. A committee was formed, a public hearing was held and a detailed report was published on updates made to the execution manuals.
But this time the state has declined to answer many questions about what options they are considering, leaving defense attorneys and inmates largely in the dark. Under state law, changes to the lethal injection method can be made administratively without legislation. And there's no timetable for the state to make a decision, said David Raybin, a Nashville attorney and former prosecutor who helped write the Tennessee death penalty law more than 30 years ago.
Raybin said the state is likely being silent on the issue because officials are being careful to avoid confusion or prompt legal challenges before they are ready to defend them. He said correction officials likely will be consulting with the attorney general's office about the drugs they are considering.
"The flip side of that is if they act precipitously then they will trigger months if not years of litigation," Raybin said. "And that would delay things as well."
He said choosing a drug whose legality has already been tested in court might allow the state to move quickly toward resuming executions.
Some states have changed their lethal injection procedures to use pentobarbital, a barbiturate that is most commonly used to euthanize animals and treat seizures. And Missouri has switched its lethal injection method to a single, fatal dose of propofol, the anesthetic blamed for Michael Jackson's death, although officials have not yet carried out an execution using that drug.
But both those drugs have their own supply issues and legal challenges as well, said Megan McCracken, the Eighth Amendment Resource Counsel with the U.C. Berkeley School of Law's Death Penalty Clinic.
Germany-based Fresenius Kabi USA is one of only two domestic suppliers of propofol, and it is the only one currently distributing in the U.S. The company announced last year that it won't sell propofol for use in U.S. executions.
McCracken said the use of propofol has been challenged in court because of the pain associated with administering the drug.
Denmark-based Lundbeck Inc., which was once the only maker of pentobarbital in the U.S., sold its rights to the drug to another manufacturer and said it never intended its product to be used in executions. The company said a distribution system meant to keep the drug out of the hands of prisons will remain in place.
McCracken said some states still use pentobarbital in executions, and at least one state -- South Dakota -- has indicated it may obtain that drug through a compounding pharmacy.
Compounding pharmacies mix drugs to order for hospitals and clinics. But the U.S. Food and Drug Administration is pushing for more regulation of these facilities after a massive fungal meningitis outbreak last year that has been linked to a Massachusetts compounding pharmacy.
"If this practice grows, I imagine we will see additional challenges because the use of a compounding facility certainly raises a lot of questions," McCracken said.