A Fulton County judge has temporarily halted the execution of an inmate while she considers his challenge to Georgia's recent switch to a new legal injection drug.

Roy Willard Blankenship was to be executed Thursday for the 1978 murder of a Savannah woman. It would be the first in Georgia using pentobarbital as part of its three-drug combination.

Superior Court Judge Wendy Shoob said Tuesday she wanted time to review the case, and that her ruling could come within days.

Defense attorneys say the use of pentobarbital is untested, unreliable and unsafe.

State attorneys say there's no evidence backing the claims.

Georgia made the switch after regulators seized the state's supply of sodium thiopental over questions about how it was obtained.

Tags: Georgia, Fulton County, death row inmate, execution, lethal injection, Roy Willard Blankenship, execution drug