Georgia is switching one of the drugs it uses to execute prisoners after federal regulators seized the state's stockpile of a sedative used in the three-drug execution combination, the state corrections department said Friday.

The Georgia Department of Corrections will substitute pentobarbital for sodium thiopental, which is in scarce supply nationwide, said Robert Jones, the department's general counsel. It would be used as the first part of a three-drug combination with pancuronium bromide and potassium chloride.

Jones said the state is switching to pentobarbital because it's readily available throughout the U.S. and several other death penalty states have already switched to the drug.

"We're confident it will be effective," he said.

The decision comes weeks after Georgia surrendered its supply of sodium thiopental to the Drug Enforcement Administration amid questions about whether the prison officials circumvented the law to obtain the supply.

The change in drugs should clear the way for Georgia to execute Troy Anthony Davis, who was sentenced to die for the 1989 slaying of a Savannah police officer.

Prosecutors have spent more than two decades trying to execute Davis and won a key legal battle in March when the U.S. Supreme Court rejected what could be his final appeal. But the state couldn't schedule his execution because it didn't have the lethal injection drug.

Many of the nation's 34 death penalty states have scrambled to find a new supplier of sodium thiopental after its sole manufacturer in the U.S. stopped making the drug in January. Several states postponed executions amid the shortage, and some have looked overseas to secure a supply.

Georgia's stockpile of sodium thiopental _ believed to be around 20 grams, enough for at least four executions _ has been under scrutiny since corrections officials released documents in court that showed the state bought the drug from Dream Pharma in London.

Defense attorneys call it a fly-by-night supplier that operates from the back of a driving school. The firm hasn't responded to repeated emails and phone calls seeking comment.

John Bentivoglio, who represents a condemned Georgia inmate, has said Georgia may have also failed to properly register with the DEA before importing a controlled substance. He said the violation means "adulterated, counterfeit or otherwise ineffective" sodium thiopental could be used in executions.

State officials say they don't have concerns about its quality.

"We have no concerns about the particular pharmaceuticals we used to carry out executions at all," Jones told the Associated Press. "They were appropriately packaged, appropriately labeled. We're confident also the state didn't break any criminal laws of any kind. It's a regulatory question, and the question was whether we had sent a letter to the DEA advising them we were importing from overseas."

He said that question is still under investigation. The Justice Department declined to comment on the probe.

Georgia officials have laid the groundwork for a switch for weeks. Corrections officials met with counterparts in Ohio and Oklahoma, which have already used pentobarbital to execute inmates. They have also collected hundreds of pages of legal filings and other documents about the drugs, and drafted several proposals for the switch, according to more than 1,000 pages of files reviewed by The Associated Press.

Georgia is one of at least 10 states that have switched or are considering a switch to pentobarbital, a surgical sedative that's also commonly used to euthanize animals. Oklahoma, Ohio, Texas, South Carolina and Alabama are among those that have already switched to pentobarbital, and other states said they were planning a similar move.

The switch allows state officials to set an execution date for Davis, who has become a cause celebre for the international anti-death penalty movement amid claims he is innocent. State authorities have set three previous execution dates for the condemned man since 2007 only to have each postponed so judges could review the case.

Chatham County District Attorney spokeswoman Alicia Johnson said the office was "not immediately" filing paperwork to seek an execution order for Davis.

The DEA has also taken supplies of sodium thiopental from Kentucky, Tennessee, Alabama and South Carolina.

Hospira Inc. of Lake Forest, Ill., said in January it would no longer make sodium thiopental. Records reviewed by The Associated Press found that as supplies of sodium thiopental dwindled, at least seven states _ Arizona, Arkansas, California, Georgia, Kentucky, Nebraska and Tennessee _ obtained sodium thiopental overseas, with several of them citing Georgia as the trailblazer.

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Associated Press Writer Russ Bynum in Savannah contributed to this report.

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