Cyanide specific antidotes

Treatment No specific antidote some authorities recommend the nitrite portion of the conventional cyanide antidote kit. 

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. 

TABLE 19.5. Supportive therapy and specific antidotal therapy for acute cyanide poisoning... 

Numerous agents analogous to the specific antidotes or compounds belonging to different pharmacological classes have also been evaluated against experimental cyanide poisoning. The eardiovaseular implications and poor pharmacokinetics of nitrite led to evaluation of yet another group... 

No specific antidote is reported. Sodium thiosulfate and other cyanide antidotes may be used. 

Possibly the most important elements of therapy are general supportive actions, which, by themselves, can effect the recovery of most casualties without further risk from specific antidotal therapy.41 They are probably the only indicated therapies for casualties of cyanide poisoning who arrive conscious at the emergency medical treatment station. 

As early as 1840, Blake42 found that the lethal effects of cyanide are neutralized by mechanical resuscitation. The use of hyperbaric oxygen in cyanide intoxication is still controversial. Supplemental oxygen with or without assisted ventilation clearly augments the effect of specific antidotes in animal studies however, despite encouraging reports,43,44 there is inconclusive evidence of further benefit from the use of hyperbaric oxygen. 

Casualties with advanced toxicity from a large amount of cyanide may require specific antidotal therapy in addition to the vigorous supportive therapy outlined above. The recommended agents or components of specific antidotal therapies for cyanide... 

Cyanide poisoning is treated with specific antidotes and supportive medical care in a hospital setting. The most important thing is tor victims to seek medical treatment as soon as possible. 

The specific antidotes are potentially dangerous in the absence of cyanide poisoning and, even when poisoning is confirmed, should only... 

In the rabbit eye, a drop of the liquid caused superficial injury. The liquid on the belly of a rabbit caused a faint erythema of short duration. The toxic effects of acetonitrile are attributed to the metabolic release of cyanide via hepatic metabolism cyanide in turn acts by inhibiting cytochrome oxidase and thus impairs cellular respiration. Evidence of the cyanide effect is supported by the reported effectiveness of specific cyanide antidotes in acetonitrile poisonings. ... 

Patients who are critical and do not satisfactorily respond to supportive therapy should be administered specific cyanide antidotes as outlined in Table 19.5. Cyanide antidotes have been classified into three main groups based on their mechanism of action (1) methemoglobin inducers, (2) sulfur donors, and (3) cobalt compounds. The definitive treatment of cyanide poisoning differs in various countries due to different medical practices and guidelines. The safety... 

In respect of potential CN terrorism we believe that the following three critical items should be added to the CDC recommendations. First, before antidotes are stockpiled there should be international agreement on the most appropriate antidote (or combinations) for the treatment of acute CN poisoning. It is our opinion that hydroxocobalamin is the optimum choice. In the context of mass casualty situations with terrorist release of cyanides on the public, the chosen antidote should be readily available, effective, easy to administer (even by responders with limited training), nontoxic, and does not adversely interact with other antidotes (Thompson, 2004). Second, with respect to CN analyses, there is a requirement for a portable equipment that is specific and, at least semiquantitative, that can be used for on-site reliable bioidentification of CN intoxication. There is also a need for a reliable and sensitive environmental method for the instantaneous measurement of HCN concentrations, and ideally continuous monitoring with automatic warning devices for installation in sites with a potential for HCN attack. Third, educational materials should be made immediately available for distribution to the general population so that they can be prepared for what to expect in the event of a CN terrorism event. 

B. Specific drugs and antidotes, if cyanide poisoning is suspected, administer sodium thiosulfate (see p 505). Sodium nitrite treatment may aggravate hypotension and should not be used. Hydroxocobalamin (p 453), 25 mg/h IV infusion, is sometimes coadministered with high-dose nitropmsside as prophylaxis against cyanide toxicity. 

Toxicology At low concentrations, acetonitrile causes headache and nausea, whilst at high concentrations, causes convulsions and death. Acetonitrile is toxic and flammable. It is metabolised into highly toxic HCN and thiocyanate. The main toxic effects of acetonitrile are attributed to the metabolic release of cyanide, in fact, specific cyanide antidotes are used in acetonitrile poisonings [5-7]. 

The organization of delivery and availability of adequate supplies of the cyanide antidote kit must be achieved. Studies of stockpile control and time necessary for the delivery to prehospital, hospital, and health departments should be performed for each region. Specifically, a study should be designed to describe the most effective response system for a mass-casualty event. These studies must emphasize an integrated analysis based on the potential of regional health, police, andfire personnel. 

Patients who are in critical condition and do not satisfactorily respond to supportive therapy should be administered specific cyanide antidotes as outlined in Table 23.5. Cyanide antidotes have been classified into... 

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