Loughner, 23, is accused of opening fire in front of a Tucson supermarket, killing six people and wounding 13 others, including former U.S. Rep. Gabrielle Giffords. He has been in a Missouri prison hospital since March 2011, undergoing a restoration to mental competency so he can stand trial.
His attorneys have argued Loughner should have had a court hearing rather than an administrative hearing at the hospital before he was medicated.
The 9th U.S. Circuit Court of Appeals Tuesday denied the defense's request that a larger panel of judges reconsider a three-judge panel's ruling about forcing Loughner to be medicated, The (Phoenix) Arizona Republic reported.
Loughner's restoration period is supposed to end Thursday.
A competency hearing is scheduled for June 27 in Tucson, the Republic said, but the judge, prosecutors and defense have said Loughner can't be released from the prison hospital.