CYANOCOBALAMIN

Cyanocobalamin Injection, USP is a sterile solution of cyanocobalamin for intramuscular or subcutaneous injection. Each mL contains 1,000 mcg cyanocobalamin. Each vial also contains Sodium Chloride, 0.9%. Benzyl Alcohol, 1.5%, is present as a preservative. Hydrochloric acid and/or sodium hydroxide may have been added during manufacture to adjust the pH (range 4.5-7.0). Cyanocobalamin appears as dark red crystals or as an amorphous or crystalline red powder. It is very hygroscopic in the anhydrous form, and sparingly soluble in water (1:80). It is stable to autoclaving for short periods at 121°C. The vitamin B 12 coenzymes are very unstable in light. The chemical name is 5,6-dimethyl-benzimidazolyl cyanocobamide; the molecular formula is C 63 H 88 CoN 14 O 14 P. The cobalt content is 4.34%. The molecular weight is 1355.39. The structural formula is represented below. Structure

: 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, USP is also suitable for the vitamin B 12 absorption test (Schilling test).

: Avoid using the intravenous route. Use of this product intravenously will result in almost all of the vitamin being lost in the urine. Pernicious Anemia: Parenteral vitamin B 12 is the recommended treatment and will be required for the remainder of the patient's life. The oral form is not dependable. A dose of 100 mcg daily for 6 or 7 days should be administered by intramuscular or deep subcutaneous injection. If there is clinical improvement and if a reticulocyte response is observed, the same amount may be given on alternate days for seven doses, then every 3 to 4 days for another 2 to 3 weeks. By this time hematologic values should have become normal. This regimen should be followed by 100 mcg monthly for life. Folic acid should be administered concomitantly if needed. Patients with Normal Intestinal Absorption: Where the oral route is not deemed adequate, initial treatment similar to that for patients with pernicious anemia may be indicated depending on the severity of the deficiency. Chronic treatment should be with an oral B 12 preparation. If other vitamin deficiencies are present, they should be treated. Schilling Test: The flushing dose is 1,000 mcg. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit.

: Sensitivity to cobalt and/or vitamin B 12 is a contraindication.

Generalized : Anaphylactic shock and death have been reported with administration of parenteral vitamin B 12 (see WARNINGS ). Cardiovascular : Pulmonary edema and congestive heart failure early in treatment; peripheral vascular thrombosis. Hematological : Polycythemia vera Gastrointestinal : Mild transient diarrhea Dermatological : Itching; transitory exanthema Miscellaneous : Feeling of swelling of entire body