Hydroxocobalamin Injection

Cobalamins are vitamin B12 which can only be synthesized by microorganisms and can only be sourced from an animal product-based diet. Cobalamin deficiency can cause megaloblastic anemia, which could be related to deficient intake of vitamin B12 or intrinsic factors, among other factors. The type of anemia, resulting from a lack of intrinsic factors is referred to as pernicious anemia.

Hydroxocobalamin (OHCbl) is a natural form of vitamin B12 available commercially. It is administrated parenterally either as an intravenous or intramuscular injection. This form of cobalamin is bioidentical to the B12 forms occurring in human physiology. 2 Initially present as a manufacturing impurity and result of photolysis in commercial cyanocobalamin (under the trade name Cytamen), 3 hydroxocobalamin was later found to be superior for many clinical conditions.

Doses of OHCbl are quite efficient for the prevention and treatment of pernicious anemia, as an antidote in cases of cyanide poisoning as well as for the treatment of Leber’s optic atrophy and tobacco amblyopia. Pernicious anemia is a fatal condition where deficiency of vitamin B12 affects the generation of healthy red blood cells and proper functioning of the nervous system. 4 In some individuals, an auto-immune response, inhibits the production of a protein called intrinsic factor which is present in the normal stomach secretion. It is responsible for vitamin B12 absorption and its absence causes clinical manifestation of its deficiency. Surgery involving stomach areas where cells responsible for intrinsic factors are affected could also lead to loss of B12 absorption. Besides this, several diseases like celiac disease, Crohn’s disease as well as HIV can interfere with vitamin B12 absorption. Other causes include the wrong types of bacteria in the small intestine, some antibiotics, and B12-feeding tapeworms.

OHCbl is found to be safe and cost-effective along with being efficient against pernicious anemia to be listed as an anti-anemic in the list of essential medicines for children published by W.H.O.

As an antidote for cyanide poisoning, hydroxocobalamin has shown many benefits over alternative antidotes. It has a very rapid response, its by-products are non-toxic. They can be easily eliminated from the body, it can be used safely even with non-poisoned patients and it does not affect the oxygen-carrying capability of blood. It has a long history of being used as an anti-dote safely against cyanide poisoning. 7 The only limitation is that it needs to be administered intravenously for a significant period of time and might need a hospital setting.

Tobacco amblyopia is caused by tobacco consumption and can be treated with hydroxocobalamin. A notable difference of improved visual acuity and color vision was reported when OHCbl was administrated IM in patients suffering from it and the performance was superior to cyanocobalamin.