Dicobalt edetate

Dodds C, McKnight C. 1985. Cyanide toxicity after immersion and the hazards of dicobalt edetate. Br Med J 291 785-786. 

Oxygen (100%), dicobalt edetate. Amyl nitrite, sod. nitrite... 

Cyanide has many sources natural (plant-Cassava), industrial (cyanide salts and nitriles), and accidental (fires). The target organ is the brain death is from respiratory arrest. Cyanide blocks cytochrome a-a3 (cytochrome oxidase) in mitochondria. The toxic level is 1 mg mL-1 in blood. Treatment involves giving dicobalt edetate (chelation). Alternatively, by giving NaNCb, levels of methemoglobin are increased, and this binds cyanide. Detoxication is catalyzed by the enzyme rhodanese, and this pathway may be increased by giving NaS207. 

This compound chelates cyanide as cobalticyanide. This drug is known to antagonize cyanide more quickly than the nitrites but its clear superiority has not been established. Intravenous administration of 300 mg of dicobalt edetate in glucose solution is the current treatment of choice in France and the United Kingdom. Serious side effects like vomiting, urticaria, anaphylactoid shock, hypotension, and ventricular arrythmias have been reported in patients receiving Kelocyanor (Van Heijst and Meredith, 1990). 

Dicobalt edetate. Cobalt forms stable, nontoxic complexes with cyanide. It is toxic (especially if the wrong diagnosis is made and no cyanide is present), causing hypertension, tachycardia and chest pain consequent cobalt poisoning is treated by giving sodium calcium edetate and i.v. glucose. 

Dicobalt edetate to chelate the cyemide is the treatment of choice when the diagnosis is certain (see p. 155). The dose is 300 mg given i.v. over one minute (5 min if condition is less serious), followed immediately by a 50 ml i.v. infusion of glucose 50% a further 300 mg of dicobalt edetate should be given if recovery is not evident within one minute. 

Other than for chelation therapy, in which the ligand is generally administered by slow, intravenous infusion, EDTA has been used in creams and ointments, pharmaceuticals, oils, soaps, bath preparations, cosmetics, and in hair dyes and permanent waving solutions. A novel application of an EDTA chelate is the use of the dicobalt chelate (dicobalt edetate) as an antidote in cyanide poisoning the CN ion forms a strong ionic complex with the Co ions in the chelate to form a relatively non-toxic and readily excretable species. 

Sodium nitrite 4-Dimethylaminophenol Dicobalt edetate Hydroxocobalamin... 

Direct complex and capture agents Cobalt compounds Dicobalt edetate Cobalt histidine Cobalt chloride Cobalt acetate Sodium cobaltinitrite Cobamide Hydroxocobalamin ... 

AC Interferes with oxygen utilization at cellular level. Drags that bind cyanide Methemoglobin formers nitrites or DAMP. Dicobalt edetate and hydroxocobalamin. Thiosulphate. Assisted ventilation. Oxygen. Profound hypotension. Rapid pulse. 

B. Treatment. Successful treatment for acute cyanide poisoning depends upon rapid fixation of the cyanide ion, either by methemoglobin (metHB) formation or by fixation with cobalt compounds. Drug treatments include, compounds producing Methemoglobin, Hydroxyocobalamin, and Dicobalt edetate. Any casualty who is fully conscious and breathing... 

Dicobalt edetate injection, sodium nitrite injection and sodium thiosulfate injection Cyanide poisoning... 

Marrs TC. Dicobalt edetate (Kelocyanor). In Meredith TJ, Jacobsen D, Haines JA, Berger J-C, van Heijst ANP, eds. Antidotes for Poisoning by Cyanide. Vol 2. In International Program on Chemical Safety/Commission of the European Communities Evaluation of Antidotes Series. Geneva, Switzerland World Health Organization and Commission of the European Communities 1993 79-94. Publication EUR 14280 EN. 

Reynolds JEF, Prasad AB, eds. Dicobalt edetate (1033-p). In Martindale The Extra Pharmacopoeia. 28th ed. London, England Pharmaceutical Press 1982 382. 

Hillman B, Bardhan KD, Bain JTB. 1974. The use of dicobalt edetate (Kelocyanor) in cyanide poisoning. Postgraduate Medical Journal 50 171-174. 

A further approach in antidote management is to use chelating compounds which actively bind the cyanide and are then excreted in the urine. The main agent in use is Kelocyanar (dicobalt edetate). Careful consideration should be given before this antidote is used. If there has been no exposure to cyanide, there may be serious adverse effects include vomiting facial, laryngeal and pulmonary oedema anaphylaxis, severe hypotension. 

Dicobalt edentate Binding of cyanide ions by dicobalt edetate and by free cyanide ions Intravenous injection Adults 300 mg (20 mL of 15 mg/mL (15 %) Child 4-7.5 mg/kg (0.3-0.5 mL/kg of 15 mg/mL (15 %) 50 mL Dextrose (500 g/L) IV immediately after each dose and oxygen 1 min Urticaria, oedema of face and neck, chest pains, dyspnoea, hypotension, convulsions... 

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