Cyanide is released in small amounts in cigarette smoke and naturally by some plants like cassava, but when highly concentrated, the chemical compound prevents the cells of the body from using oxygen and becomes a fast-acting poison.
If released during a chemical accident or deployed as a weapon during a terrorist attack, a cloud of cyanide gas could produce a horrifying scene, with victims in desperate need of an antidote. While current treatments for cyanide poisoning could be cumbersome in such a scenario, researchers say they've found an effective antidote that could be administered quickly with an EpiPen-like jab.
Existing cyanide antidotes, which include compounds like hydroxocobalamin, must be administered by an intravenous (IV) infusion so that they can dissolve well enough to be absorbed in the body. But administering an IV infusion requires a certain level of training and equipment, and it could be unwieldy at the scene of a bioterrorist attack.
"You might imagine that you're a paramedic and there are multiple people exposed to cyanide, some of them may be convulsing, it may be very difficult to get the IV line in," researcher Steven Patterson, of the University of Minnesota's Center for Drug Design, told LiveScience.
The solution that Patterson and his colleagues came up with is a substance called sulfanegen TEA, which could be delivered to the body through an intra-muscular (IM) injection, similar to the jab delivered by an epinephrine autoinjector to those suffering a severe allergic reaction.
"The antidote works by taking advantage of our natural biochemical processes, which are able to detoxify cyanide," Patterson explained. "What we do is provide the process present with the material it needs to convert cyanide into thiocyanate," which is much less toxic than cyanide and gets expelled from the body in urine.
The new substance has been tested at toxic, but sublethal, levels on animal models, Patterson said, and further experiments to test the antidote's efficacy against lethal cyanide doses are in the pipeline. The researchers have not observed any adverse events due to the drug during their safety studies, though they don't yet know the upper limits of how much of the antidote a body can safely handle, Patterson said.
The research is funded by the National Institutes of Health's CounterACT program, which seeks to develop medical countermeasures against chemical threat agents. The study was detailed this month in the Journal of Medicinal Chemistry.