A judge here recently found that pancuronium bromide, marketed under the trade name Pavulon, has "no legitimate purpose."

"The subject gives all the appearances of a serene expiration when actually the subject is feeling and perceiving the excruciatingly painful ordeal of death by lethal injection," the judge, Ellen Hobbs Lyle, wrote, describing the worst-case scenario. "The Pavulon gives a false impression of serenity to viewers, making punishment by death more palatable and acceptable to society."

Experts say there is a much more humane way of killing --specifically, through the administration of a single dose of sodium pentobarbitol.

The three drug combination is widely used in the U.S.

Lethal injection is now the dominant way Americans are executed. It is used in all 38 states that have the death penalty except Nebraska, which uses electrocution. In 10 states, prisoners may choose between lethal injection and a second method, including hanging, firing squad, electrocution and lethal gas.

Here's how the combo works:

In most methods of lethal injection, pancuronium bromide is the second drug in a three-chemical sequence. The first is sodium thiopental, a so-called ultra-short-acting barbiturate. It can be effective for only minutes. In surgery, it is used to induce rather than maintain anesthesia. Doctors like it because patients who encounter immediate complications awaken quickly enough to be saved.

The third is potassium chloride, which stops the heart and causes excruciating pain if the prisoner is conscious. "It would basically deliver the maximum amount of pain the veins can deliver, which is a lot," Dr. Mark J. S. Heath, an anesthesiologist who teaches at Columbia.

One problem with the combination of chemicals, Dr. Heath said in an interview, is that the sodium thiopental could be inadequate or wear off. That would leave the prisoner conscious, paralyzed, suffocating and subject to extreme pain from the potassium chloride. "You're in a chemical tomb," he said.

Much of the new focus stems from a lawsuit brought by Tennessee death row inmate, Abdur'Rahman . At a hearing in the case, a woman who had the drug administered during eye surgery, testified:

Carol Weihrer, who underwent eye surgery in 1998, testified for Mr. Abdur'Rahman at the hearing in May. Anesthesia was administered before the surgery, as was pancuronium bromide to immobilize the eye. But the anesthesia was ineffective. Ms. Weihrer testified that the experience was terrifying and torturous. She could not, she said, communicate that she was awake. "I remember using every ounce of my strength to try to move," she said....Ms. Weihrer called the experience "worse than death."