Updated

The parents of a 5-year-old autistic boy who died after receiving a chemical treatment have sued the doctor who administered it for wrongful death.

Mawra and Rufai Nadama, of Plymouth, England, accused Dr. Roy Kerry of causing their son, Abubakar Tariq Nadama, to die of cardiac arrest at Kerry's office immediately after the boy received chelation therapy on Aug. 23, 2005.

Chelation removes heavy metals from the body and is approved by the U.S. Food and Drug Administration only for acute heavy-metal poisoning that has been confirmed by blood tests. Some people who believe autism is caused by a mercury-containing preservative once used in vaccines say chelation may also help autistic children.

"This is a real human tragedy that never should have happened," said John Gismondi, the Pittsburgh attorney representing the Nadamas. "The doctor had no business administering this drug to a child, and he only made matters worse by giving it much too quickly."

The Nadamas had moved to the Pittsburgh area to seek treatment for the boy's autism. Gismondi said he believes the suit is the first filed in the U.S. involving an autistic child who died from chelation therapy.

Kerry, of Greenville, Pennsylvania, did not immediately return a message left at his office Monday.

The lawsuit also names another doctor who allegedly directed a medical assistant to administer the fatal dose at Kerry's behest at the Advanced Integrative Medicine Center in Portersville, Pennsylvania about 30 miles (48 kilometers) north of Pittsburgh.

The Nadamas are also suing ApotheCure Inc., of Dallas, Texas, and several sister corporations, which they contend supplied, made or tested the chelation solution but allegedly did not provide appropriate warnings and instructions about its use. ApotheCure did not immediately return a call for comment.

No criminal charges have been filed, but local and state prosecutors are investigating the boy's death.

The Department of State, Pennsylvania's physician licensing agency, filed six disciplinary charges in September against Kerry, including unprofessional conduct and breaching the standard of care. Those charges were still pending and could result in fines or his license being suspended or revoked.

The agency alleged Kerry prescribed an IV push -- meaning the drugs are administered in one dose intravenously -- despite warnings that this method can be lethal. He also prescribed the wrong formula of the drug, officials said.

The lawsuit filed Monday echoes those allegations and the results of an autopsy that showed the boy's cardiac arrest was caused by a sudden drop in his calcium level.

The Centers for Disease Control and Prevention, which also investigated the boy's death, has said he was given a synthetic amino acid called Disodium EDTA instead of Calcium Disodium EDTA. Both are odorless, colorless liquids and may have been confused, the CDC found.

Butler County District Attorney Randa Clark, the Pennsylvania attorney general and did not immediately return calls about the status of their investigations.

Some doctors have used chelation to treat autism, believing mercury or other heavy metals cause the condition's symptoms. However, medical evidence does not support that belief, and the drug is not approved for that use, officials with the Centers for Disease Control and Prevention said.

In February 2005, a 2-year-old girl with lead poisoning was treated with three chelating agents and died at a hospital hours later from what an autopsy concluded was cardiac arrest due to depleted levels of calcium.