This comprehensive review by the authors examines the pros and cons of two cyanide antidote treatments sodium thiosulfate, which is a component of the commonly referred to Pasadena or Lilly kit, and hydroxocobalamin, which is a precursor of vitamin B12 and has been in use for years in many countries and exclusively in Europe.
The authors review the current literature supporting the use of these agents as well as the current research that indicates the need for increased awareness of cyanide poisoning in combination with smoke inhalation. They state that empiric treatment, which would be the automatic administration of a given therapy when the condition is suspected, should be both safe and effective.
They conclude that hydroxocobalamin meets both of these criteria.The Street
There is growing evidence that cyanide represents a major toxic component of smoke inhalation victims. Additionally, cyanide is rated as one of the most easily weaponizable toxic agents. Although the U.S. government has placed significant emphasis on cholinergic agents with the provision of Mark I kits and stockpiling of Atropine, little has been done to prepare us for cyanide as a weapon a mass destruction.
To date, the only treatment for cyanide poisoning has been the use of amyl nitrate capsules followed by intravenous sodium nitrate then followed by sodium thiosulfate. These agents have the potential to cause significant hypotension, and their mechanism of action results in the production of methemoglobin, which in the setting of carbon monoxide exposure would cause significant hypoxemia.
Hydroxocobalamin has been proven to be safe and effective. It essentially binds the cyanide ion and is excreted in the urine. The most common side effects are that it turns the patient s skin and urine red, a condition that lasts for four to six days and is otherwise without symptoms. It does cause a moderate rise in blood pressure in non-poisoned volunteers, but it s speculated that this effect would not be seen in cyanide poisoning because cyanide causes hypotension.
Recent studies show that neither EMS nor our hospitals are prepared for mass casualty care of cyanide poisoning. In Paris, because of the concern for cyanide in combination with CO poisoning, all firefighters and fire victims with signs of significant smoke inhalation are given hydroxocobalamin in the field. Their studies show significant improvement in both mortality and morbidity.
I suspect that it won t be long before we adopt this as a standard of care in the U.S.