A new antidote for cyanide is more effective and has fewer side effects than existing treatments, a Mississippi researcher reports.

Development of the antidote, called alpha-ketoglutaric acid, was sponsored by the Army in hopes of protecting soldiers from possible cyanide attack, says Arthur S. Hume, who is heading the research.

"They were interested in the possible use by an enemy of cyanide as a chemical warfare agent," Hume said in a telephone interview from the University of Mississippi. He said use of the antidote before exposure to poison gas could make it possible to "perhaps survive an attack of cyanide."

The U.S. Army Medical Research and Development Command has contributed $70,000 to the research, he says.

Cyanide occurs naturally, and also is produced by the burning of many plastics and fabrics. As many as 35 percent people killed in fires are found to have toxic levels of cyanide in their blood, Hume says. Cyanide is also one of the poisons that were given off by the Union Carbide leak in Bhopal, India.

Existing antidotes -- sodium thiosulfate and sodium nitrite -- are either too slow for emergency use or have toxic properties of their own, he says.

The new antidote, he says, appears to be equally effective if given before poisoning, as a preventive measure, or afterwards.

People can die from cyanide poisoning several days after exposure. Supplies would have to be kept in emergency rooms, he says, because death can also come quickly. "In our gas chamber up there in the state penetentiary, 15 minutes," Hume points out.