Vitamin B12 (cyanocobalamin and analogues)
Cyanocobalamin
The FDA lists this product in 38 strengths and forms.
Indications
Cyanocobalamin is indicated for vitamin B 12 deficiencies due to malabsorption which may be associated with the following conditions:
- Addisonian (pernicious) anemia
- Gastrointestinal pathology, dysfunction, or surgery, including gluten enteropathy or sprue, small bowel bacteria overgrowth, total or partial gastrectomy
- Fish tapeworm infestation
- Malignancy of pancreas or bowel
- Folic acid deficiency It may be possible to treat the underlying disease by surgical correction of anatomic lesions leading to small bowel bacterial overgrowth, expulsion of fish tapeworm, discontinuation of drugs leading to vitamin malabsorption (see Drug Interactions ), use of a gluten-free diet in nontropical sprue, or administration of antibiotics in tropical sprue. Such measures remove the need for long-term administration of cyanocobalamin. Requirements of vitamin B 12 in excess of normal (due to pregnancy, thyrotoxicosis, hemolytic anemia, hemorrhage, malignancy, hepatic and renal disease) can usually be met with oral supplementation. Cyanocobalamin injection is also suitable for the vitamin B 12 absorption test (Schilling test).
Contraindications
Sensitivity to cobalt and/or vitamin B 12 is a contraindication.
Warnings and precautions
Patients with early Leber's disease (hereditary optic nerve atrophy) who were treated with cyanocobalamin suffered severe and swift optic atrophy. Hypokalemia and sudden death may occur in severe megaloblastic anemia which is treated intensely. Anaphylactic shock and death have been reported after parenteral vitamin B 12 administration. An intradermal test dose is recommended before Cyanocobalamin injection is administered to patients suspected of being sensitive to this drug.
This product contains Benzyl Alcohol. Benzyl Alcohol has been reported to be associated with a fatal "Gasping Syndrome" in premature infants. This product contains aluminum that may be toxic. Aluminum may reach toxic levels with prolonged parenteral administration if kidney function is impaired. Premature neonates are particularly at risk because their kidneys are immature, and they require large amounts of calcium and phosphate solutions, which contain aluminum.



