VITAMIN B12 (cyanocobalamin injection)

VITAMIN B12 (cyanocobalamin injection)

OFFICE ADMINISTRATION / SELF ADMINISTRATION

Indications for Prior Authorization:

• Vitamin B₁₂ 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
• Vitamin B₁₂ supplementation to reduce toxicity associated with pemetrexed or pralatrexate
• Requirements of vitamin B₁₂ in excess of normal (due to pregnancy, thyrotoxicosis, hemolytic anemia, hemorrhage, malignancy, hepatic and renal disease) can usually be met with oral supplementation.

Prior authorization criteria:

• Prior authorization required for any dosing greater than cyanocobalamin 1000mcg once monthly
• Diagnosed vitamin B₁₂ deficiency, AND
• Has tried and failed oral cyanocobalamin as evidenced by medical record documentation (does not apply to pernicious anemia)

Dosing:

• Pernicious anemia: parenteral vitamin B₁₂ is the recommended treatment and will be required for the remainder of the patient's life. 
  • 100 mcg IM daily for 6 or 7 days; with clinical improvement and reticulocyte response, the same dose may be given on alternate days for seven doses, then every 3 to 4 days for another 2 to 3 weeks. 
  • Maintenance: 100 mcg monthly
• Patients with normal intestinal absorption: when the oral route is not adequate, initial treatment similar to that for patients with pernicious anemia may be indicated depending on deficiency severity.
• Supplementation to reduce toxicity associated with pemetrexed: IM: 1000 mcg every 9 weeks, beginning 1 to 3 weeks prior to pemetrexed treatment initiation; continue for 3 weeks after last pemetrexed dose.
• Supplementation to reduce toxicity associated with pralatrexate: IM: 1000 mcg every 8 to 10 weeks; begin cyanocobalamin within 10 weeks prior to pralatrexate treatment initiation.

Approval:

• One year