Nascobal (Cyanocobalamin)

NASCOBAL is indicated for:

• Vitamin B₁₂ maintenance therapy in adult patients with pernicious anemia who are in remission following intramuscular vitamin B₁₂ therapy and who have no nervous system involvement
• Treatment of adult patients with dietary, drug-induced, or malabsorption-related vitamin B₁₂ deficiency not due to pernicious anemia
• Prevention of vitamin B₁₂ deficiency in adult patients with vitamin B₁₂ requirements in excess of normal
  Limitations of Use

• NASCOBAL should not be used for the vitamin B₁₂ absorption test (Schilling test).
• In patients with correctible or temporary causes of vitamin B₁₂ deficiency, the benefit of continued long-term use of NASCOBAL following adequate correction of vitamin B₁₂ deficiency and underlying disease has not been established.
• The effectiveness of NASCOBAL in patients with active symptoms of nasal congestion, allergic rhinitis or upper respiratory infection has not been determined. Treatment with NASCOBAL should be deferred until symptoms have subsided.

Nasal spray:  500 mcg/0.1 mL (per actuation), packaged in a single-use device containing 0.125 mL of solution

• Severe Optic Atrophy in Patients with Leber’s Disease
  [see Warnings and Precautions (5.1)]
  .
• Anaphylactic Reactions
  [see Warnings and Precautions (5.2)]
  .
• Hypokalemia and Thrombocytosis Due to Intense Treatment of Megaloblastic Anemia
  [see Warnings and Precautions (5.4)]
  .

Chloramphenicol may decrease the efficacy of NASCOBAL when used for treatment of anemia. If NASCOBAL is used for the treatment of anemia concomitantly with chloramphenicol, monitor for reduced efficacy and if needed, consider an alternative therapy

Cyanocobalamin is a synthetic form of vitamin B₁₂. The chemical name is 5,6-dimethyl-benzimidazolyl cyanocobamide. The cobalt content is 4.35%. The molecular formula is C₆₃H₈₈CoN₁₄O₁₄P, which corresponds to a molecular weight of 1355.38 and the following structural formula:

Figure 1. Nascobal Chemical Structure

Cyanocobalamin occurs as dark red crystals or orthorhombic needles or crystalline red powder. It is very hygroscopic in the anhydrous form, and sparingly to moderately soluble in water (1:80). Its pharmacologic activity is destroyed by heavy metals (iron) and strong oxidizing or reducing agents (vitamin C), but not by autoclaving for short periods of time (15-20 minutes) at 121°C. The vitamin B₁₂ coenzymes are very unstable in light.

NASCOBAL (cyanocobalamin) nasal spray is a solution of cyanocobalamin, USP (vitamin B₁₂) for administration as a spray to the nasal mucosa. Each single-use device of NASCOBAL NASAL SPRAY contains 0.125 mL of a 500 mcg/0.1 mL solution of cyanocobalamin with, benzalkonium chloride in purified water, citric acid, glycerin and sodium citrate. The spray solution has a pH between 4.5 and 5.5. Each spray delivers an average of 500 mcg of cyanocobalamin per actuation.