At one point, a federal appeals court halted the forced medication, but resumed it once mental health experts at the prison concluded that Loughner’s condition was deteriorating further.
Loughner has demonstrated bizarre behavior since his arrest.
He was removed from a May 25, 2011, court hearing when he lowered his head to within inches of the courtroom table, then lifted his head and began a loud and angry rant.
His psychologist has said that since Loughner has been forcibly medicated, his condition has improved. He sat still and expressionless for seven hours at a hearing in September 2011.
Pete Yost reported from Washington.