Nitrite sodium, cyanide poisoning

Other Uses. Other appHcations for sodium nitrite include the syntheses of saccharin [81-07-2] (see Sweeteners), synthetic caffeine [58-08-2] (22), fluoroaromatics (23), and other pharmaceuticals (qv), pesticides (qv), and organic substances as an inhibitor of polymerization (24) in the production of foam blowing agents (25) in removing H2S from natural gas (26) in textile dyeing (see Textiles) as an analytical reagent and as an antidote for cyanide poisoning (see Cyanides). 

Sodium nitrite (NaNOg) is used by emergency medical personnel as an antidote for cyanide poisoning (for this purpose, it must be administered immediately). Based on the discussion of cyanide poisoning in Section 21.10, suggest a mechanism for the life-saving effect of sodium nitrite. 

For cyanide and cyanogen, antidote should be administered as soon as possible. The Lilly Cyanide Antidote Kit contains amyl nitrite, sodium nitrite, and sodium thiosulfate. Cobalt edentate or 4-dimethylaminophenol are alternative antidotes for cyanide poisoning. Benzodiazepines or barbiturates may be required to control severe seizures. 

Undoubtedly sodium nitrite is a vasodilator [1]. This is seen from anecdotal evidence when nitrite is used as an antidote to cyanide poisoning hypotension is a major hazard. However, in ex vivo experiments the effect of nitrite is small but the situation in vivo is more difficult to assess, for reasons that will be clear shortly. It is now generally assumed that nitrite acts as a vasodilator because it can undergo a spontaneous reaction to give NO. The termolecular equation (Eq. (1)) sometimes given for this process is certainly incorrect as termoleculer reactions very rarely occur. 

Bhattacharya R. 1995. Therapeutic efficacy of sodium nitrite and 4-dimethylaminophemol or hydroxylamine co-administration against cyanide poisoning in rats. Hum ExpToxicol 14 29-33. 

Treatment of cyanide poisoning includes rapid administration of activated charcoal (although charcoal binds cyanide poorly, it can reduce absorption) and general supportive care. The conventional antidote kit available in the USA includes two forms of nitrite (amyl nitrite and sodium nitrite) and sodium thiosulfate. The nitrites induce methemoglobinemia, which binds to free CI T creating the less toxic cyanomethemoglobin thiosulfate is a cofactor in the enzymatic conversion of CN to the much less toxic thiocyanate (SCINT). Recently, the FDA approved a concentrated form of hydroxocobalamin, which is now available as the Cyanokit (EMD Pharmaceuticals, Durham, North Carolina). Hydroxocobalamin (one form of vitamin B12) combines rapidly with CN to form cyanocobalamin (another form of vitamin B12). 

The administration of sodium thiosulfate (12.5 grams a 25 percent solution administered intravenously at a flow rate of 2.5-5mL/min over a 10-minute period of time) will result in the conversion of the much more toxic cyanide to its less toxic thiocyanate form. This treatment of cyanide poisoning with sodium thiosulfate should follow the use of sodium nitrite. The administration of both the sodium nitrite and sodium thiosulfate is dependent upon the hemoglobin of the patient. The Fe2+ form of hemoglobin will also be oxidized by the sodium thiosulfate and sodium nitrite to the Fe3+ form (methemoglobin). This oxidized form binds cyanide readily to form a stable complex which can be metabolized. See ASIDEon CYANIDE. 

Cyanide poisoning is treated with attention to airway and cardiopulmonary management. Cyanide poisoning is treated with a specific antidote of amyl nitrite perles, sodium nitrite, and sodium thiosulfate. 

Sodium nitrite is the most prevalent drug for cyanide poisoning. It takes about 12 min to generate approximately... 

Baskin, S.I., Horowitz, A.M., Nealley, E.W. (1992). The antidotal action of sodium nitrite and sodium thiosulfate against cyanide poisoning. J. Clin. Pharmacol. 32 368-75. 

Bhattacharya, R., Jeevaratnam, K., Raza, S.K., Dasgupta, S. (1993). Protection against cyanide poisoning by co-adminis-tration of sodium nitrite and hydroxylamine in rats. Hum. Exp. Toxicol. 12 33-6. 

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