On paper, the drug that states are increasingly counting on to replace a sedative used in executions shares several drawbacks with the one that's no longer readily available.
Both were intended for other uses. Each was or is made by only one company in the U.S. And the substitute drug will have to run the same legal gauntlet that the first drug survived.
There is one key difference, however: Experts say there is plenty of the replacement, pentobarbital, and it's not likely the manufacturer will abruptly halt production and touch off the kind of supply crisis that struck the first drug's maker.
There already was a shortage of sodium thiopental before its manufacturer, Hospira Inc., said in January it would no longer make the drug, sending most of the 35 death penalty states scrambling for an alternative. The Lake Forest, Ill.-based company quit production when lawmakers in Italy, home of the company's new factory, demanded assurances that the substance would not be used in executions.
Lundbeck Inc., which makes pentobarbital, is based in Denmark _ another European country that opposes the death penalty.
However, Lundbeck and outside experts said there is no shortage in sight. And independent data collected by a health firm showed the drug's sales have steadily increased since 2005.
A shortage doesn't appear to be on the horizon, though it could arise without warning, said Dr. David Varlotta, a Tampa, Fla., anesthesiologist who sits on the board of the American Society of Anesthesiologists. That could throw the capital punishment calendar in the U.S. off schedule all over again.
"The shortages come up so rapidly, we don't have time to prepare," he said, noting that his hospital is facing shortfalls of key anesthetics because of the volatility of the supply chain.
Using pentobarbital for lethal injections also raises medical questions, since it has only been used in a few executions and rarely is used in humans. Varlotta, for one, said he has not used pentobarbital since 1986.
"If departments of corrections are moving toward pentobarbital, they're moving away from the expertise of anesthesiologists," said Varlotta, who was appointed in 2007 to study Florida's lethal injection procedure after a botched execution there.
Others say there's no reason to fear a switch. Mark Dershwitz, a University of Massachusetts anesthesiologist, said pentobarbital could be readily adopted by states as long as the supply holds up. The biggest difference between the two drugs, he said, is that pentobarbital knocks out patients longer.
"And no one can say that's a disadvantage when used in an execution," he said.
The shortage of sodium thiopental _ which for more than 30 years has been the first of a three-drug cocktail used by dozens of states _ had corrections departments across the country delaying executions and looking to overseas manufacturers not approved by federal regulators. Officials had hoped the more potent pentobarbital would ease the crisis.
Oklahoma adopted pentobarbital last year as part of its three-drug combination. As the shortage of sodium thiopental grew worse, Ohio announced it would use it alone to put inmates to death. And an Associated Press review revealed every state but South Carolina said it is considering switching to alternatives, which is only likely to intensify scrutiny of pentobarbital.
Sally Benjamin Young, a spokeswoman for Lundbeck's U.S. subsidiary that makes pentobarbital, would not disclose how much pentobarbital the company manufactures in the U.S. each year. But she said the company has had no supply problems thus far and did not expect future supply issues.
However, using the drug for executions is not what the company intended and "goes against everything we're in business to do," she said.
The drug was originally introduced to market in 1973 and Lundbeck acquired the product rights in 2003, Young said. The company, whose U.S. headquarters are a few miles from Hospira's in Deerfield, Ill., has been making the drug in the same Kansas facility since 2007, and Young said Lundbeck has no plans to move the product to another factory.
Sales of pentobarbital grew by 16 percent between 2009 and 2010, according to IMS Health. The independent firm said some $25.5 million worth of the drug, brand name Nembutal, was sold in 2010 _ more than double the $10.1 million sold in 2006.
Lundbeck said it has no way of keeping the drug out of death chambers. And it's unlikely the Danish government can step in as Italian authorities did, said Maya Foa, an investigator with London-based civil rights group Reprieve, which opposes the death penalty. Regulators could be hamstrung because the company's manufacturing plant is in the U.S., she said.
"There's not a lot they can do about it," said Foa, who is visiting Denmark this week to meet with local officials. "They say once they sell a product, they have no control over how it's used."
Pentobarbital likely will have to pass legal muster in U.S. courts. As they did with sodium thiopental, inmates have begun to argue that the drug does not adequately sedate the condemned, leading to a painful death that violates the constitutional ban on cruel and unusual punishment.
The U.S. Supreme Court ultimately ruled that sodium thiopental was constitutional.