Basic Profile / Key Facts
Drug Category
- Antianemic Agents
- Essential Vitamin
- Vitamins (Vitamin B Complex)
Dosage Forms
- Intra-nasal gel
- Parenteral (oral)
Indications
For treatment of pernicious anemia (due to lack of or inhibition of intrinsic factor) and for prevention and treatment of vitamin B 12 deficiency.
Pharmacology
Vitamin B12 is a water-soluble organometallic compound with a trivalent cobalt ion bound inside a corrin ring. It isneeded for nerve cells and red blood cells, and to make DNA. Vitamin B12 deficiency is the cause of several forms of anemia.
Mechanism of Action
Vitamin B12 is used in the body in two forms: Methylcobalamin and 5-deoxyadenosyl cobalamin. The enzyme methionine synthase needs methylcobalamin as a cofactor. This enzyme is involved in the conversion of the amino acid homocysteine into methionine. Methionine in turn is required for DNA methylation. 5-Deoxyadenosyl cobalamin is a cofactor needed by the enzyme that converts L-methylmalonyl-CoA to succinyl-CoA. This conversion is an important step in the extraction of energy from proteins and fats. Furthermore, succinyl CoA is necessary for the production of hemoglobin, the substances that carries oxygen in red blood cells.
Absorption
Readily absorbed in the lower half of the ileum.
Toxicity
Anaphylactic reaction (skin rash, itching, wheezing)-after parenteral administration. ORL-MUS LD50 > 8000 mg/kg
Biotrnasformation / Drug Metabolism
Hepatic
Contraindications
Hemochromatosis and hemosiderosis are contraindications to iron therapy.
Drug Interactions
No information provided.
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