A Danish company has announced that it is taking steps to try to prevent prison officials in the United States from using a powerful sedative it makes to execute prisoners.

Lundbeck said Friday that it was reviewing all orders for its drug Nembutal, also known as pentobarbital, to block any shipments to prisons in states that execute prisoners.

The announcement creates the latest obstacle to capital punishment in the United States. Many states have begun using pentobarbital to execute prisoners instead of the anesthetic sodium thiopental, which became unavailable when Hospira of Lake Forest, Ill., announced in January that it would stop making it. That decision was prompted by opposition to the death penalty by lawmakers in Italy, where the company had planned to shift its production of the drug.

“Lundbeck adamantly opposes the distressing misuse of our product in capital punishment,” Lundbeck’s chief executive Ulf Wiinberg said in a statement. “Since learning about the misuse we have vetted a broad range of remedies — many suggested during ongoing dialogue with external experts, government officials and human rights advocates. After much consideration, we have determined that a restricted distribution system is the most meaningful means through which we can restrict the misuse of Nembutal.”

While the new policy “can’t make any guarantees” that the drug will not be used for executions, “we are confident that our new distribution program will play a substantial role in restricting prisons’ access to Nembutal for misuse as part of lethal injection.”

Although Nembutal represents only 1 percent of the company’s global sales, the company said it decided against simply withdrawing the drug from the market because the compound “continues to meet an important medical need” in the United States. The drug is “used to treat serious conditions, such as a severe and life-threatening” form of epilepsy, the company said.

Thirty-four states have the death penalty. All allow for lethal injection, and until recently most had used a three-drug cocktail of sodium thiopental, pancuronium bromide and potassium chloride. In the wake of sodium thiopental’s scarcity, states have begun substituting pentobarbital or simply using pentobarbital alone.

In addition to being used to treat epilepsy, pentobarbital has also long been used to euthanize animals.

“Lundbeck’s move has serious implications for those states that already use pentobarbital for lethal injection executions as well as those states that were preparing to make the switch,” said Deborah Denno, a Fordham University law professor who is a death penalty opponent.

“In due time, states will have to find an alternative drug, thereby repeating the cycle that started when states abandoned sodium thiopental. This development throws doubt yet again on the viability of using drug injections as an execution method because surely this cycle has no foreseeable end,” she said.