Hydroxocobalamin monohydrochloride is primarily used in the treatment of vitamin B12 deficiency. It is particularly effective in addressing conditions such as pernicious anemia, where the body cannot absorb vitamin B12 properly. This compound is also employed in emergency medicine as an antidote for cyanide poisoning, where it binds to cyanide molecules to form cyanocobalamin, a non-toxic compound that can be excreted by the body. Additionally, it is utilized in certain cases of tobacco amblyopia and Leber's optic atrophy, as it helps in the regeneration of damaged nerve tissues. In some instances, it is administered intramuscularly to ensure direct absorption into the bloodstream, making it a reliable option for patients with absorption issues.