(CNN) -- Ahead of next week's scheduled execution of convicted killer Christopher Sepulvado, the Louisiana Department of Corrections has switched to the same controversial two-drug combination that was used in Ohio this month, the Louisiana department said.
"The reason for the change is that DOC has been unable to procure the drug, pentobarbital, specified in the one-drug protocol," DOC spokeswoman Pam Laborde said in a statement. "The Department will continue to attempt to obtain the drug or drugs necessary for either of the two protocols."
Gary Clements, part of Sepulvado's legal team, said an appeal will be filed Tuesday.
"We're not challenging capital punishment in his case ... just how it's going to be done," Clements said.
Sepulvado's execution is scheduled for February 5. He was sentenced to death for killing his 6-year-old stepson in 1992.
Like Ohio, Louisiana has been forced to find new drug protocols after European-based manufacturers banned U.S. prisons from using their drugs in executions -- among them, Danish-based Lundbeck, which manufactures pentobarbital.
Ohio inmate Dennis McGuire appeared to gasp and convulse for about 10 minutes before he died January 16 by lethal injection using the new combination of drugs -- midazolam, a sedative; and the painkiller hydromorphone -- according to reporters who witnessed the execution.
McGuire's family said the execution was "torture."
CNN legal analyst Sunny Hostin said McGuire's execution will likely spark debate over whether the use of the drugs constitutes cruel and unusual punishment prohibited by the U.S. Constitution.
"Whenever there's a change in the lethal injection process, clearly it's subject to legal proceedings, and perhaps we will see those," Hostin said this month.
The change in execution drugs was not a surprise, Clements said.
"We predicted they would have trouble finding pentobarbital, and they would have their backs against the wall and they would be forced to do something drastic," Clements said. "(The) announcement has proven us correct."