What is the antidote for cyanide poisoning?

Hydroxycobalamin, also known as vitamin B12a, is effective as an antidote for cyanide poisoning because it works by binding to cyanide ions to form a non-toxic compound that can be excreted by the body. This binding helps to mitigate the toxic effects of cyanide, which inhibits cellular respiration by blocking the use of oxygen at the cellular level.

When administered, hydroxycobalamin increases the levels of vitamin B12 in the body, thereby providing a means to safely remove cyanide. It is important in acute scenarios where cyanide is suspected, such as smoke inhalation from a fire or exposure to certain chemicals.

Other options, such as sodium thiosulfate, while they can also be used in the management of cyanide poisoning, do so in a secondary manner by providing sulfur to convert cyanide into thiocyanate, which is less toxic. Activated charcoal is typically used for gastrointestinal decontamination and would not be effective if cyanide poisoning is suspected after significant absorption into the bloodstream. N-Acetylcysteine is primarily utilized as a treatment for acetaminophen overdose and does not have a role in cyanide toxicity.