Editing Cyanide (section)

===Antidote===
[[Hydroxocobalamin]] reacts with cyanide to form [[cyanocobalamin]], which can be safely eliminated by the kidneys. This method has the advantage of avoiding the formation of methemoglobin (see below). This antidote kit is sold under the brand name Cyanokit and was approved by the U.S. FDA in 2006.<ref>{{EMedicine|article|814287|Cyanide Toxicity|treatment}}</ref>

An older cyanide antidote kit included administration of three substances: [[amyl nitrite]] pearls (administered by inhalation), [[sodium nitrite]], and [[sodium thiosulfate]]. The goal of the antidote was to generate a large pool of [[ferric]] iron ({{chem2|Fe(3+)}}) to compete for cyanide with cytochrome a<sub>3</sub> (so that cyanide will bind to the antidote rather than the enzyme). The [[nitrite]]s [[oxidize]] [[hemoglobin]] to [[methemoglobin]], which competes with cytochrome oxidase for the cyanide ion. Cyanmethemoglobin is formed and the [[cytochrome oxidase]] enzyme is restored. The major mechanism to remove the cyanide from the body is by enzymatic conversion to [[thiocyanate]] by the [[mitochondrial]] enzyme [[rhodanese]]. Thiocyanate is a relatively non-toxic molecule and is excreted by the kidneys. To accelerate this detoxification, sodium thiosulfate is administered to provide a sulfur donor for [[rhodanese]], needed in order to produce thiocyanate.<ref>{{cite journal | last1 = Chaudhary | first1 = M. | last2 = Gupta | first2 = R. | year = 2012 | title = Cyanide Detoxifying Enzyme: Rhodanese | journal = Current Biotechnology | volume = 1 | issue = 4 | pages = 327–335 | doi = 10.2174/2211550111201040327}}</ref>