mHb generation is thought to be a primary mechanism by which the NO(2)(-) ion antagonizes cyanide. Amyl nitrite and sodium nitrite (NaNO(2)) antagonize cyanide toxicity in part by oxidizing hemoglobin to methemoglobin (mHb), which then scavenges cyanide. Summary StructureĬyanide inhibits aerobic metabolism by binding to the binuclear heme center of cytochrome c oxidase (CcOX). Evidence-based medicine for Chemical Defense - including efficacy and safety A. Chemical Defense therapeutic area(s) - including key possible usesĪmyl nitrite is typically used with other agents (sodium nitrite and sodium thiosulfate) as an antidote for acute cyanide poisoning. Name of Chemical Defense therapeutic agent/deviceĪmyl nitrite 2. It may not be ideal, but until other treatments become more affordable, it may be the best chance we have for patients potentially exposed to cyanide.1. I’ll discuss the Cyanokit in a future article.Īs always, follow local protocol, but look into whether this Sodium Thiosulfate is permitted in your region and discuss with your medical director about adding it to your armamentarium, especially for treating victims from house fires. While it is very promising, the cost will prevent it being stocked on most EMS units, at least until the price decreases. There is a new treatment out that was approved two years ago, the Cyanokit, but it is very expensive – more than $800. For children, it should be weight based, given 1.65 mL/kg (of 25 percent solution) over 10 minutes. Sodium Thiosulfate is administered IV, 12.5 grams (50mL) over one to two minutes. It should be given early, before this occurs. It is unlikely to help a patient already in cardiac arrest, but it is reasonable to try it even in these cases. The only drawback to thiosulfate is that is it slow. Research has shown that providing thiosulfate accelerates the conversion of cyanide to a safer form three to four times as quick. If given too quickly in a patient with kidney problems, it may cause tinnitus, blurry vision, delirium or seizures - but compared to death from cyanide poisoning, this can be handled and the benefit exceeds the risk. If we provide more thiosulfate, then this enzyme can detoxify more cyanide.Īs EMS cannot really use the first two drugs in the Cyanide Antidote Kit for a smoke inhalation victim for reasons mentioned before, it has been proposed that perhaps the third drug, Sodium Thiosulfate, can be given alone. The enzyme uses thiosulfate to convert the cyanide. However, if there is too much cyanide, then this enzyme is overwhelmed. There is an enzyme that converts cyanide to a form that can be eliminated from the body. The body can be routinely exposed to small amounts of cyanide and needs to be able to handle this small amount on an everyday basis. The third drug in the kit, Sodium Thiosulfate, helps the body detoxify the cyanide. Finally, the cost of the kit is more than $300, costly for large services with many ambulances. It tends to disappear from stocks as a result. In addition, there are security concerns as Amyl Nitrate, which is supplied in ampoules for inhalation before an IV can be started, has been reported to be used for aphrodisiac purposes. They are not in the typical formulary for EMS providers, and the most common cyanide exposure for EMS is likely to be a house fire when they should not be used anyway. The creation of methemoglobin in this situation would likely be fatal.Īmyl Nitrite and Sodium Nitrate create methemoglobinemia, and can be given if there is no exposure to carbon monoxide. However, if the victim has been exposed to carbon monoxide from a house fire, they will have even less functional hemoglobin as carboxyhemoglobin, which is created from exposure to CO, cannot carry oxygen either.

In patients that have been exposed to cyanide only, this would be fine - the body can survive with only 70 percent of hemoglobin functioning to carry oxygen. Normally we want to create about 30 percent methemoglobin. The downside of creating this form of hemoglobin, called methemoglobin, is that it cannot carry oxygen. This will pull the cyanide out of the mitochondria of the cells and allow the resumption of normal energy production. One of the treatments for cyanide poisoning is to turn some of the hemoglobin in the body into a form that will attach to cyanide. Next, there is Sodium Nitrate for IV administration. First, there is Amyl Nitrite for inhalation. These are in short supply - often there is only one or two available to each emergency department.

It is also known as the Lilly Kit, Pasadena Kit or the Taylor Kit. In the hospital, a common treatment is the Cyanide Antidote Kit.

Poison antidote kit