Defense attorney Ellis Johnston told the 9th U.S. Circuit Court of Appeals in San Francisco the medication Loughner is being given to make him competent to stand trial could have a negative impact on his trial by dampening his emotions, CNN reported.
"What is the effect of the drugs on the likelihood of achieving a fair trial? That is what the court has to address," Johnston said.
Johnston told the judges the drugs are not making Loughner "less dangerous, and they may be exacerbating his dangerousness."
"It's even worse if the side effects of those drugs will prohibit him from expressing himself appropriately at trial," the defense attorney said.
Assistant U.S. Attorney Christina Cabanillas countered that Loughner "could revert to being a danger to himself" if the medication is withdrawn.
"It is his mental illness that is the cause of the danger in the hospital setting."
Senior Circuit Judge J. Clifford Wallace asked Johnston whether the court shouldn't wait for Loughner to complete his four months of treatment before considering whether Loughner's ability to work with his attorneys is impeded.
Johnston answered that the U.S. Supreme Court requires the courts to consider whether the drugs could create a substantial chance that Loughner won't have a fair trial.
Loughner, 23, who prosecutors say suffers schizophrenia, is fighting a second four-month course of drugs being administered at a federal mental hospital in Springfield, Mo., where he is being held pending his trial for the slaying of six people, including a federal judge and young girl, and wounding of 13 others, including U.S. Rep. Gabrielle Giffords, D-Ariz., outside a Tucson grocery store in January.