University of Minnesota
February 16, 2012
University of Minnesota researchers have invented a new antidote for cyanide.
A new way to treat and prevent cyanide poisoning
By Deane Morrison
It lurks in apple seeds, fruit pits, and the cassava root consumed widely in Africa. It's released by house fires when materials like some acrylics, polyurethane, and nylons burn. And it could be used in terrorist attacks.
It's cyanide, one of the deadliest poisons around. Your body can handle a little of it, but for larger exposures an antidote is necessary.
Current antidotes can work, but they're slow. That could change, however, now that three researchers at the University of Minnesota's Center for Drug Design (CDD) have synthesized Sulfanegen, a faster-acting antidote, and California-based startup Vytacera Pharma will develop and market it.
"It's really cheap to make Sulfanegen, so it could be issued widely," says co-inventor Steve Patterson, associate director of CDD. "It would probably be stockpiled by first responders such as paramedics and firefighters."
For soldiers and civilians
The idea began with Herbert Nagasawa, who held joint appointments at the "U" and the VA Medical Center and is now an emeritus professor and adjunct at CDD. With the help of a grant from the center, he initiated a study to develop a new cyanide antidote based on the body's own way of detoxifying small amounts of cyanide in food. He was inspired by seeing troops in the first Gulf War wearing gas masks for protection against Saddam Hussein's chemical warfare agents. Later he, CDD director Robert Vince, and Patterson received a grant from the National Institutes of Health's CounterACT (countermeasures against chemical threats) program.
Cyanide is usually released into the air as hydrogen cyanide, a gas that disperses rapidly. Thus, it is most dangerous in closed spaces. Current antidotes must be injected intravenously, a process that requires a skilled professional.
"If there are many casualties, you can get a situation where paramedics can't treat everybody," says Patterson. "And since victims of cyanide poisoning often have convulsions, that makes it even harder.
One of the antidotes used in the United States is hydroxycobalamin, a compound that's not very water-soluble.
"Because of this, it takes about 15 minutes to inject it," Patterson says. "You have to give it a little at a time."
But Sulfanegen can be injected in a muscle, which doesn't require that level of skill.
Killing the killer
Cyanide kills by shutting off the body's ability to use oxygen. The oxygen we breathe serves one purpose: to carry away the byproducts of respiration, the process by which energy is extracted from food and converted to a usable form. Cyanide interferes with an enzyme that allows these byproducts to be passed to oxygen, and with a big enough dose, respiration in vital organs like hearts and brains shuts down.
The researchers synthesized and tested several compounds and named the one that worked best Sulfanegen. Its job is to help out an enzyme that's key to the body's own cyanide-defense system.
"It provides the enzyme with a compound it needs to detoxify cyanide," Patterson says.
Researchers at CDD and at Vytacera must complete safety and efficacy studies in order to obtain FDA approval. Sulfanegen will likely be available to medical professionals in several years.