Category: vitamin
Aliases: OH-Cbl, Hydroxycobalamin, Vitamin B12a, Cyanokit
Cobalamin with a hydroxyl ligand at the central cobalt. Binds transcobalamin II more tightly than cyanocobalamin, giving a substantially longer plasma residence time (effective t½ weeks to months after IM). Converted intracellularly to methylcobalamin and adenosylcobalamin via the canonical MMACHC/MMADHC trafficking pathway. Also acts as a potent cyanide chelator — forms cyanocobalamin which is renally excreted, hence its Rx role (Cyanokit) in smoke-inhalation poisoning.
IM: 26.2h, IV: 26.2h