Yes

Vitamin, Water Soluble

Dental: Vitamin B₁₂ deficiency

Medical: Treatment of pernicious anemia; vitamin B₁₂ deficiency; increased B₁₂ requirements due to pregnancy, thyrotoxicosis, hemorrhage, malignancy, liver or kidney disease

A/C (if dose exceeds RDA recommendation)

Hypersensitivity to cyanocobalamin or any component, cobalt; patients with hereditary optic nerve atrophy

I.M. route used to treat pernicious anemia; vitamin B₁₂ deficiency for >3 months results in irreversible degenerative CNS lesions; treatment of vitamin B₁₂ megaloblastic anemia may result in severe hypokalemia, sometimes, fatal, when anemia corrects due to cellular potassium requirements. B₁₂ deficiency masks signs of polycythemia vera; vegetarian diets may result in B₁₂ deficiency; pernicious anemia occurs more often in gastric carcinoma than in general population.

1% to 10%:

Dermatologic: Itching

Gastrointestinal: Diarrhea

<1%: Peripheral vascular thrombosis, urticaria, anaphylaxis

Neomycin, colchicine, anticonvulsants may decrease absorption, chloramphenicol may decrease B₁₂ effects

Clear pink to red solutions are stable at room temperature; protect from light; incompatible with chlorpromazine, phytonadione, prochlorperazine, warfarin, ascorbic acid, dextrose, heavy metals, oxidizing or reducing agents

Coenzyme for various metabolic functions, including fat and carbohydrate metabolism and protein synthesis, used in cell replication and hematopoiesis

Absorption: Absorbed from the terminal ileum in the presence of calcium; for absorption to occur gastric "intrinsic factor" must be present to transfer the compound across the intestinal mucosa

Distribution: Principally stored in the liver, also stored in the kidneys and adrenals

Protein binding: Bound to transcobalamin II

Metabolism: Converted in the tissues to active coenzymes methylcobalamin and deoxyadenosylcobalamin

Recommended daily allowance (RDA):

Children: 0.3-2 mcg

Adults: 2 mcg

Nutritional deficiency: Oral: 25-250 mcg/day

Anemias: I.M. or deep S.C. (oral is not generally recommended due to poor absorption and I.V. is not recommended due to more rapid elimination):

Pernicious anemia, congenital (if evidence of neurologic involvement): 1000 mcg/day for at least 2 weeks; maintenance: 50-100 mcg/month or 100 mcg for 6-7 days; if there is clinical improvement, give 100 mcg every other day for 7 doses, then every 3-4 days for 2-3 weeks; follow with 100 mcg/month for life. Administer with folic acid if needed.

Children: 30-50 mcg/day for 2 or more weeks (to a total dose of 1000-5000 mcg), then follow with 100 mcg/month as maintenance dosage

Adults: 100 mcg/day for 6-7 days; if improvement, administer same dose on alternate days for 7 doses; then every 3-4 days for 2-3 weeks; once hematologic values have returned to normal, maintenance dosage: 100 mcg/month. Note: Use only parenteral therapy as oral therapy is not dependable.

Vitamin B₁₂ deficiency:

Children:

Neurologic signs: 100 mcg/day for 10-15 days (total dose of 1-1.5 mg), then once or twice weekly for several months; may taper to 60 mcg every month

Hematologic signs: 10-50 mcg/day for 5-10 days, followed by 100-250 mcg/dose every 2-4 weeks

Adults: Initial: 30 mcg/day for 5-10 days; maintenance: 100-200 mcg/month

Schilling test: I.M.: 1000 mcg

Serum potassium, erythrocyte and reticulocyte count, hemoglobin, hematocrit

Normal range of serum B₁₂ is 150-750 pg/mL; this represents 0.1% of total body content. Metabolic requirements are 2-5 mg/day; years of deficiency required before hematologic and neurologic signs and symptoms are seen. Occasional patients with significant neuropsychiatric abnormalities may have no hematologic abnormalities and normal serum cobalamin levels, 200 pg/mL (SI: >150 pmol/L), or more commonly between 100-200 pg/mL (SI: 75-150 pmol/L). There exists evidence that people, particularly elderly whose serum cobalamin concentrations <300 pg/mL, should receive replacement parenteral therapy; this recommendation is based upon neuropsychiatric disorders and cardiovascular disorders associated with lower sodium cobalamin concentrations.

Methotrexate, pyrimethamine, and most antibiotics invalidate folic acid and vitamin B₁₂ diagnostic microbiological blood assays

None reported

Anticonvulsants may decrease the absorption of cyanocobalamin

No information available to require special precautions

No effects or complications reported

Use exactly as directed. Pernicious anemia may require monthly injections for life. Report skin rash; swelling, pain, or redness of extremities; or acute persistent diarrhea.

Oral therapy is markedly inferior to parenteral therapy; monitor potassium concentrations during early therapy

Gel, nasal:

Ener-B®: 400 mcg/0.1 mL

Nascobal™: 500 mcg/0.1 mL (5 mL)

Injection: 30 mcg/mL (30 mL); 100 mcg/mL (1 mL, 10 mL, 30 mL); 1000 mcg/mL (1 mL, 10 mL, 30 mL)

Tablet [OTC]: 25 mcg, 50 mcg, 100 mcg, 250 mcg, 500 mcg, 1000 mcg

Lindenbaum J, Healton EB, Savage DG, et al, "Neuropsychiatric Disorders Caused by Cobalamin Deficiency in the Absence of Anemia or Macrocytosis," N Engl J Med, 1988, 318(26):1720-8.

Olszewski AJ, Szostak WB, Bialkowska M, et al, "Reduction of Plasma Lipid and Homocysteine Levels by Pyridoxine, Folate, Cobalamin, Choline, Riboflavin, and Troxerutin in Atherosclerosis," Atherosclerosis, 1989, 75(1):1-6.

Regland B, Gottfries CG, and Lindstedt G, "Dementia Patients With Low Serum Cobalamin Concentration: Relationship to Atrophic Gastritis," Aging Milano, 1992, 4(1):35-41.

Schjonsby H, "Vitamin B₁₂ Absorption and Malabsorption," Gut, 1989, 30(12):1986-91.

Silbergleit R and Lee DC, "Bowel Obstruction and Radiopaque Vitamin B₁₂"Pseudobezoar"," Am J Emerg Med, 1995, 13(1):112-3.