Two death row inmates have been executed in Florida and Texas, the states that hold the record this year for executions in the United States, penal authorities said.
In Florida, Darius Kimbrough, 40, died from lethal injection after the US Supreme Court rejected his final appeal, said Misty Cash, a spokeswoman for the Florida Department of Corrections.
He was convicted and sentenced to death for the rape and killing of a 28-year-old woman in 1991 in her apartment in Orange County.
The anaesthetic drug he received, midazolam, was used for only the second time in Florida.
As stocks of lethal injection drugs are depleted, most US states that have the death penalty are using new ones or turning to new suppliers.
This is creating controversy and a flurry of appeals from prisoners fearing their executions will be unbearably painful.
For his last meal, Kimbrough was served two slices of pizza, a fried green tomato, fried chicken, chicken gizzards, chocolate chip ice cream and fruit punch, and he finished most of his meal. He made no final statement, Cash said.
In Texas, Jamie McCoskey, 49, was executed in the town of Huntsville, said Jason Clark, spokesman for the Texas justice department.
He was administered a lethal injection of pentobarbital, a veterinary product that Texas obtained from non-certified suppliers, after official ones refused to provide it for executing people.
McCoskey, who did not appeal his death sentence, was sentenced to die over the 1991 kidnapping of a Houston couple. The 20-year-old man was killed and his girlfriend was raped.
The two men were the 33rd and 34th people executed so far this year in the United States.
Kimbrough was the seventh in Florida, a record since 1984, when eight men were put to death.
Only Texas has surpassed Florida this year, with McCoskey the 15th person to be put to death.
Barring a stay of execution, both states are scheduled to carry out another execution on December 3.
