VPT 421: Veterinary Toxicology (2+0)

TREATMENT

• The treatment of cyanide poisoning needs to be undertaken very rapidly if it is to be successful.
• The approach consists of administration of sodium nitrite and sodium thiosulphate.
• Sodium nitrite administered intravenously converts haemoglobin to methaemoglobin.
• Ferric iron of methaemoglobin complexes with cyanide to form cyanmethaemoglobin and thus reactivates cytochrome oxidase.
• Sodium thiosulphate detoxifies cyanmethaemoglobin by converting cyanide moiety to thiocyanate, which is non toxic.
• Sodium nitrite treatment should not be repeated, as there is danger of producing nitrite poisoning.
• In horses and cattle 10ml of a 20% solution of sodium nitrite intravenously followed immediately with 50 ml of 20% solution of sodium thiosulphate.
• In sheep 10ml of 10% sodium nitrite and 10% of 20ml sodium thiosulphate should be given. In dogs 20mg/kg as 1% solution of sodium nitrite and 1g/kg of 25% solution sodium thiosulphate should be administered.
• All injections should be given slowly.
• Hydroxycobalamine and other compounds of cobalt have also been shown to be of value.