OKLAHOMA CITY - A worldwide shortage of one of the three drugs used in lethal injection has prompted one stay of execution so far in Oklahoma and could affect future scheduled executions. Dara Downs has more.

Jeffrey Matthews was scheduled for execution on August 18, but Oklahoma Department of Corrections spokesman Jerry Massie says after testing the sodium thiopental that would have been used to execute Matthews they weren't satisfied with the purity of the drug and elected to use a substitute.

"We were able to obtain another drug that is chemically very similar, has the same effect basically, and according to the statute, just says an ultra short acting barbiturate. It doesn't name a specific type of drug, so we felt like that would be appropriate," Massie says.

A federal judge then granted Matthews a stay of execution, and set a hearing date for October 15 so the courts could decide whether the new drug does indeed fit the Oklahoma statute.

"I believe the courts will be making a decision as to whether any type of substitute concoction or drug still fits within the same perimeters to withstand constitutional challenges and that it's not cruel and unusual punishment," Massie says.

Director for the Death Penalty Information Center Richard Dieter says this isn't the first time a drug shortage has caused a stay of executions, and says according to the drug maker it could be early 2011 before more of the drug is available.

"This is not a settled issue, and this is just one more chapter in the long story of trying to use the medical profession in a criminal justice setting," Dieter says.

State Representative Samson Buck says depending on the judge's ruling in October, Oklahoma may look at changing the statute to avoid future problems with drug shortages.

"If there is a specific drug substitute that the DOC or the state feels is comparable or the same, then we may be able to incorporate that into the statute to alleviate any problem in the future with the stay of executions," Buck says.

Massie says the state has one other execution scheduled for October in addition to Matthews, but has been assured only enough sodium thiopental for one person and says they will have to wait for the judge's ruling to see how the shortage will affect both executions.