Dennis McGuire, 53, was executed on Jan. 16 for the 1989 murder of 22-year-old Joy Stewart, the Columbus Dispatch reported.
His children, Amber and Dennis McGuire, filed a lawsuit Friday in U.S. District Court in Columbus, alleging that their father's execution violated the 8th Amendment to the U.S. Constitution, which protects against "cruel and unusual" punishment.
The lawsuit alleges the state used lethal injections midazolam, a sedative, and hydromorphone, a morphine derivative, to kill McGuire that the U.S. Food and Drug Administration "has not approved for that purpose," said attorney Jon Paul Rion, who is representing McGuire's children.
After being injected with the drugs, McGuire gasped, snorted and choked for about 10 minutes before succumbing to the drugs.
There was no indication that the drug combination caused McGuire's struggle. However, this was the first time the two drugs were used together in an execution in the United States.