Decontamination Decontamination of people exposed to hydrogen<unk>  gas only requires removal of the outer clothing and the washing of their hair. Those exposed to liquids or powders generally require full decontamination. Antidote The International Programme on Chemical Safety issued a survey (IPCS/CEC Evaluation of Antidotes Series) that lists the following antidotal agents and their effects: oxygen, sodium thiosulfate, amyl nitrite, sodium nitrite, 4-dimethylaminophenol, hydroxocobalamin, and dicobalt edetate ('Kelocyanor'), as well as several others. Other commonly-recommended antidotes are 'solutions A and B' (a solution of ferrous sulfate in aqueous citric acid, and aqueous sodium carbonate, respectively) and amyl nitrite. The United States standard<unk>  antidote kit first uses a small inhaled dose of amyl nitrite, followed by intravenous sodium nitrite, followed by intravenous sodium thiosulfate. Hydroxocobalamin is newly approved in the US and is available in Cyanokit antidote kits. Sulfanegen TEA, which could be delivered to the body through an intra-muscular (IM) injection, detoxifies<unk>  and converts the<unk>  into thiocyanate, a less toxic substance. Alternative methods of treating<unk>  intoxication are used in other countries. The Irish Health and Safety Executive (HSE) has recommended against the use of solutions A and B because of their limited shelf life, potential to cause iron poisoning, and limited applicability (effective only in cases of<unk>  ingestion, whereas the main modes of poisoning are inhalation and skin contact). The HSE has also questioned the usefulness of amyl nitrite due to storage/availability problems, risk of abuse, and lack of evidence of significant benefits. It also states that the availability of kelocyanor at the workplace may mislead doctors into treating a patient for<unk>  when this is an erroneous diagnosis. The HSE no longer recommends a particular<unk>  antidote. Agent Description Nitrites The nitrites oxidize some of the hemoglobin's iron from the ferrous state to the ferric state, converting the hemoglobin into methemoglobin.<unk>  binds avidly to methemoglobin, forming cyanmethemoglobin, thus releasing<unk>  from cytochrome oxidase. Treatment with nitrites is not innocuous as methemoglobin cannot carry oxygen, and severe methemoglobinemia may need to be treated in turn with methylene blue. Thiosulfate The evidence for sodium thiosulfate's use is based on animal studies and case reports: the small quantities of<unk>  present in dietary sources and in cigarette smoke are normally metabolized to relatively harmless thiocyanate by the mitochondrial enzyme rhodanese (thiosulfate<unk>  sulfurtransferase), which uses thiosulfate as a substrate. However, this reaction occurs too slowly in the body for thiosulfate to be adequate by itself in acute<unk> . Thiosulfate must therefore be used in combination with nitrites. Hydroxocobalamin Hydroxocobalamin, a form (or vitamer) of vitamin B12 made by bacteria, and sometimes denoted vitamin B12a, is used to bind<unk>  to form the harmless cyanocobalamin form of vitamin B12. 4-Dimethylaminophenol 4-Dimethylaminophenol (4-DMAP) has been proposed in Germany as a more rapid antidote than nitrites with (reportedly) lower toxicity. 4-DMAP is used currently by the German military and by the civilian population. In humans, intravenous injection of 3 mg/kg of 4-DMAP produces 35 percent methemoglobin levels within 1 minute. Reportedly, 4-DMAP is part of the US Cyanokit, while it is not part of the German Cyanokit due to side effects (e. g. hemolysis). Dicobalt edetate Cobalt ions, being chemically similar to iron ions, can also bind<unk> . One current cobalt-based antidote available in Europe is dicobalt edetate or dicobalt-EDTA, sold as Kelocyanor. This agent chelates<unk>  as the cobalticyanide. This drug provides an antidote effect more quickly than formation of methemoglobin, but a clear superiority to methemoglobin formation has not been demonstrated. Cobalt complexes are quite toxic, and there have been accidents reported in the UK where patients have been given dicobalt-EDTA by mistake based on a false diagnosis of<unk> . Because of its side effects, it should be reserved only for patients with the most severe degree of exposure to<unk> ; otherwise, nitrite/thiosulfate is preferred. Glucose Evidence from animal experiments suggests that coadministration of glucose protects against cobalt toxicity associated with the antidote agent dicobalt edetate. For this reason, glucose is often administered alongside this agent (e.g. in the formulation 'Kelocyanor').It has also been anecdotally suggested that glucose is itself an effective counteragent to<unk> , reacting with it to form less toxic compounds that can be eliminated by the body. One theory on the apparent immunity of Grigori Rasputin to<unk>  was that his killers put the poison in sweet pastries and madeira wine, both of which are rich in sugar; thus, Rasputin would have been administered the poison together with massive quantities of antidote. One study found a reduction in<unk>  toxicity in mice when the<unk>  was first mixed with glucose. However, as yet glucose on its own is not an officially acknowledged antidote to<unk> . 3-Mercaptopyruvate prodrugs The most widely studied<unk> -metabolizing pathway involves utilization of thiosulfate by the enzyme rhodanese, as stated above. In humans, however, rhodanese is concentrated in the kidneys (0.96 units/mg protein) and liver (0.15 u/mg), with concentrations in lung, brain, muscle and stomach not exceeding 0.03 U/ml. In all these tissues, it is found in the mitochondrial matrix, a site of low accessibility for ionized, inorganic species, such as thiosulfate. This compartmentalization of rhodanese in mammalian tissues leaves major targets of<unk>  lethality, namely, the heart and central nervous system, unprotected. Rhodanese is also found in red blood cells, but its relative importance has not been clarified.) A different<unk> -metabolizing pathway, 3-mercaptopyruvate sulfurtransferase (3-MPST, ), which is more widely distributed in mammalian tissues than rhodanese, is being explored. 3-MPST converts<unk>  to thiocyanate, using the cysteine catabolite, 3-mercaptopyruvate (3-MP). However, 3-MP is extremely unstable chemically. Therefore, a prodrug, sulfanegen sodium (2, 5-dihydroxy-1,4-dithiane-2,5-dicarboxylic acid disodium salt), which hydrolyzes into 2 molecules of 3-MP after being administered orally or parenterally, is being evaluated in animal models. Oxygen therapy Oxygen therapy is not a cure in its own right. However, the human liver is capable of metabolizing<unk>  quickly in low doses (smokers breathe in hydrogen<unk> , but it is such a small amount and metabolized so fast that it does not accumulate).
Cyanide poisoning
Foreign body aspiration
Chlorine gas poisoning
Carbon monoxide poisoning
Salicylate poisoning
Nitrogen dioxide poisoning
Strychnine poisoning
Tin poisoning