Skip to main content

Cruel and Usual: Is Capital Punishment by Lethal Injection Quick and Painless?

About 2/3 of the states use a combination of barbituric, paralytic and toxic agents for executions, despite a lack of scientific evidence supporting their effectiveness. Although the procedure may be subject to FDA approval, the agency has avoided any ruling on the cocktail's efficacy in delivering a merciful death.

A shortage of sodium thiopental, a fast-acting barbiturate and general anesthetic used in lethal injections of death-row convicts, has delayed several such executions throughout the U.S. and reignited a long-standing debate over the combination of chemicals used to carry out capital punishment. Most recently, Arizona inmate Jeffrey Landrigan was executed Tuesday night only after a delay caused by a legal battle over the source and quality of the sodium thiopental used as part of the lethal injection.

Lethal injection is used for capital punishment by the federal government and 36 States, at least 30 of which use the same combination of three drugs: sodium thiopental (a barbiturate to induce anesthesia), pancuronium bromide (a muscle relaxant that paralyzes all the muscles of the body) and potassium chloride (a salt that speeds the heart until it stops). This protocol was developed in 1977 for the state of Oklahoma by then–Chief Medical Examiner Jay Chapman, but it has never been codified or sanctioned by the U.S. Food and Drug Administration (FDA).

The only U.S. maker of sodium thiopental, Hospira, Inc., in Lake Forest, Ill., has reported a shortage of the raw materials needed to make the drug. When Arizona law enforcement last week declined to identify its source of the sodium thiopental intended for Landrigan, his lawyers seized on the opportunity. On October 21, they requested a stay of execution, contending that their client could suffocate painfully if the anesthetic comes from an unknown source and did not work properly before the pancuronium bromide and potassium chloride kicked in. U.S. District Judge Roslyn Silver initially blocked the execution, but she was overruled Tuesday by the U.S. Supreme Court, which voted 5-4 that a condemned prisoner does not need to know the source of the drugs used in his execution.

The Superior Court of Maricopa County, Ariz., originally sentenced Landrigan to death in 1990 after convicting him of 1st-degree felony murder in the strangulation and stabbing death of Chester Dean Dyer of Phoenix. At the time of the murder Landrigan was an escapee from an Oklahoma prison, where he was serving time following a conviction in that state of assault and battery with a deadly weapon, second-degree murder, and possession of marijuana.

Regardless of whether Landrigan's legal team was simply using the drug shortage as stalling tactic, their legal maneuvering brings to the fore a contentious dispute over the science (or some would say lack thereof) behind lethal injection executions in the U.S. For more than two decades, it has been argued that the FDA should be required to certify the safety and effectiveness of drugs used to carry out executions (as it does for drugs used to euthanize animals). The FDA, wanting to stay out of the capital punishment debate, disagrees.

In 2008 the U.S. Supreme Court upheld a lower court ruling that the state of Kentucky's 3-drug method of lethal injection did not constitute "cruel and unusual punishment," as defined by the Eighth Amendment. Some scientists disagree. Scientific American spoke with University of Miami Miller School of Medicine molecular biologist Teresa Zimmers about this controversial topic.

[An edited transcript of the interview follows.]

You and a group of colleagues in 2007 published a report in PLoS Medicine that examined public records of executions. What was the purpose, and what sort of reaction did you receive?

We were actually trying to look at whether there was any evidence that the three-drug protocol—sodium thiopental, pancuronium bromide and potassium chloride—acted in the way it was supposed to act. We analyzed the time to death or the time to different events, such as cardiac arrest, in order to understand what might be the mechanism of death. We found no evidence to support the use of this protocol, the dosage of the drugs or the order in which the drugs were administered in executions.

A lot of responses to the study were negative—people assumed that we had a specific political agenda. This began to change as people looked at our data more closely. We were invited to the March 2008 Fordham Urban Law Journal Symposium, "The Lethal Injection Debate: Law and Science," by Fordham University School of Law professor Deborah Denno to represent the medical and scientific aspects of it. Supreme Court Justice Stephen Breyer also used our studies as part of his research for Baze v. Rees in 2008, which upheld an earlier ruling in Kentucky that the state's approach to administering lethal injections does not violate the "cruel and unusual punishments" ban promised in the Eighth Amendment. Breyer's research—our paper—did not uphold the constitutionality, but rather argued for the likelihood of unrecognized pain and suffering.

What concerned you and your colleagues about the way lethal injections are administered?

There's no record of a medical or scientific inquiry into whether this would be the best method. And there isn't any medical evidence to support this approach. Part of the paradox is that it looks like a medical procedure, but it hasn't been rigorously tested. There are no controlled trials, data collection, analysis or peer review of the processes to determine whether it works the way it's been said to work.

Why is sodium thiopental used as part of a lethal injection execution?

Sodium thiopental was chosen to render the person deeply unconscious and unable to feel the paralysis brought on by the pancuronium bromide, which causes the person to lose the ability to breathe. And the potassium chloride is extremely painful. Some people have said that three to 5 grams of sodium thiopental alone should be enough to induce death. [In December 2009 Ohio became the first state to use a single dose of sodium thiopental to execute death-row inmates.] We looked at whether inmates died reliably after the sodium thiopental, and it's not clear this is the case. We also determined that the doses of sodium thiopental used are not always as "massive" as claimed. It's not even clear how much a massive dose is in this context. We found that, at most, the highest doses were two times the lethal dose for animals, regardless of the inmate's weight.

It has been reported that in addition to a shortage of sodium thiopental, the doses that some states stockpile are set to expire before scheduled executions can be carried out. What sort of shelf life does sodium thiopental have?

Sodium thiopental has quite a long shelf life—up to 48 months in its unconstituted form. Once you add liquid, it's been reported to be stable for 24 hours or, if it's kept cold, it can last for 7 days. They typically prepare it on the day of execution. Shelf life may be a problem because states perform executions infrequently and now don't have a supply of new doses.

Source: Scientific American, October 27, 2010

Comments

Most viewed (Last 7 days)

Oklahoma executes James Pavatt

Pavatt claimed innocence in the slaying of an Oklahoma City advertising executive for insurance money. His co-defendant and former lover Brenda Andrew is also on death row. James Pavatt made no final statement before being executed Thursday for killing his lover’s estranged husband nearly 25 years ago. Pavatt merely shook his head when asked by Oklahoma Department of Corrections Chief of Operations Jason Sparks if he had any last words. Pavatt appeared to share a quick word with Michael Scott, his spiritual advisor, after microphones inside the death chamber had been cut off.

Oklahoma Death Row inmate James Pavatt scheduled to be executed Thursday

James Pavatt is scheduled to be executed on Thursday for the 2001 killing of an Oklahoma City man. OKLAHOMA CITY—Oklahoma Death Row inmate James Pavatt is set to be executed for the 2001 murder of advertising executive Rob Andrew. His execution is scheduled for Nov. 12, 2026. In 2004, Pavatt and his lover/co-conspirator, Brenda Andrew, were sentenced to death for planning the killing of her estranged husband in an attempt to claim his $800,000 life insurance policy. Brenda is the only woman on Oklahoma’s death row.

Judge allows Tennessee death row inmates to include botched executions in lawsuit

NASHVILLE, Tenn. (WKRN) — Two failed executions in Tennessee are now at the center of a growing legal battle over the state’s lethal injection protocol after a judge ruled in favor of death row inmates Friday. A Davidson County judge ruled death row inmates can expand their lawsuit to include new allegations stemming from the botched executions of Tony Carruthers and Christa Pike. The original lawsuit, filed in March 2025, argues Tennessee’s death penalty protocol violates the constitutional rights of death row inmates with complex medical conditions. More than one year later, the state then failed to execute two inmates: Tony Carruthers and Christa Pike.

Two men set to be executed in Texas and Oklahoma today

The U.S. was preparing to carry out two executions on Thursday, one in Oklahoma and one in Texas. In Texas, the condemned man is John Allen Rubio, 46, who is set to be put to death at the state prison in Huntsville. He was convicted of beheading three young children he was raising in a 2003 killing that rattled a community along the U.S.-Mexico border. The other man facing execution is James Pavatt, 73, who is set to die by lethal injection at Oklahoma's state penitentiary in McAlester.

Texas executes John Rubio

Texas man who killed 3 children is put to death, hours after an Oklahoma execution James Pavatt was put to death in Oklahoma for Rob Andrew’s killing. In Texas, John Allen Rubio was executed for the deaths of Julissa Quesada, John E. Rubio, and Mary Jane Rubio.  A Texas man convicted of fatally stabbing and beheading 3 young children in a squalid, windowless apartment in 2003 was executed Thursday evening, hours after Oklahoma put another man to death. 

Why Many Americans Think Christa Pike Should Undergo a Second Execution Attempt

On October 20, Reuters released the results of a survey showing that 33% of the American public want Tennessee to try again to put Christa Pike to death. Another 26% are undecided. That means 59% of the public would support or be open to such a possibility. I want to suggest a reason why. Second execution attempts are rare in this country and, as a result, the public knows little if anything about them. That may help explain why so many would give Tennessee another chance to kill Christa Pike.

Iran executes three more January protesters accused of spying for Israel, US

In a statement, the judiciary said that “the death sentences of Hassan Deoband, Hamid Kazemi, and Reza Zangana were carried out on charges of ‘participating in operational action for the infamous Zionist regime and the United States and hostile groups.’” ERBIL, Kurdistan Region of Iraq – Iran on Sunday executed three more protesters over their involvement in the nationwide demonstrations in January, the judiciary announced, accusing them of spying for the United States and Israel and destroying infrastructure. 

Alabama executes Michael Shannon Taylor

Alabama executes man convicted of 1991 double murder  The state of Alabama carried out the execution of 54-year-old Michael Shannon Taylor Thursday night for the 1991 murders of an elderly Etowah County couple, 35 years and 1 day after the crime.  Taylor, convicted in 1993 on 3 counts of capital murder, was sentenced to death unanimously by a jury for killing 83-year-old Ivan Ernest Moore and 79-year-old Lucille Moore inside their Gadsden home during a robbery. Taylor was 19 at the time. 

Iran | 10 executed in Ahvaz, Isfahan, Karaj

Four prisoners, including an Afghan national, were executed at Ghezel Hesar Prison in Karaj on Wednesday, November 4, 2026. All four had been sentenced to death under Iran’s qisas (retributive justice) laws on murder charges. According to information obtained by the Hengaw Organization for Human Rights, one of the executed prisoners was identified as Gol Agha Eskandari, an Afghan national. Eskandari had been convicted of murder following a dispute between neighbors in the Khorasan Square area of Tehran in July 2024 and subsequently sentenced to death.

Florida executes Jesse Guardado

Man convicted of 2004 killing is put to death in Florida’s 19th execution this year, tying a record Florida carried out a record-tying 19th execution of the year in an unusual instance of 3 states administering the death penalty on the same day. Jesse Guardado was pronounced dead at 6:13 p.m. following a 3-drug injection at a state prison in Starke. He had pleaded guilty to fatally stabbing 75-year-old Jackie Malone inside her Walton County home in 2004 before stealing her jewelry box, $80, and other valuables to buy drugs. The woman had helped him get a job and housing.