Cyanocobalamin injection for vitamin B12 deficiency treatment

Cyanocobalamin injection is a sterile vitamin B12 solution administered by intramuscular or subcutaneous injection. It is used to treat vitamin B12 deficiencies caused by malabsorption or related conditions, including pernicious anemia. The injection ensures rapid and reliable absorption, supporting blood cell production and nervous system health.

Cyanocobalamin injection is indicated for vitamin B12 deficiencies due to malabsorption associated with:

• Addisonian (pernicious) anemia
• Gastrointestinal diseases such as gluten enteropathy (sprue), small bowel bacterial overgrowth, or following gastrectomy
• Fish tapeworm infestation
• Malignancies of the pancreas or bowel
• Folic acid deficiency related to vitamin B12 malabsorption

It is also used for the vitamin B12 absorption test (Schilling test). This injection is intended for patients who cannot absorb vitamin B12 orally or require rapid correction of deficiency.

Cyanocobalamin

Cyanocobalamin serves as a synthetic form of vitamin B12, essential for growth, cell reproduction, production of blood cells, and nervous system maintenance. After injection, cyanocobalamin is quickly absorbed and transported by specific binding proteins to body tissues, especially the liver for storage. It supports DNA synthesis and myelin formation, preventing neurological damage caused by deficiency.

Administration: Intramuscular or deep subcutaneous injection is preferred. Intravenous use is discouraged as it leads to rapid urinary loss and reduced storage.

Pernicious anemia regimen: 100 mcg daily for 6-7 days, then 100 mcg every other day for 7 doses, followed by 100 mcg every 3-4 days for 2-3 weeks until hematologic values normalize; thereafter, 100 mcg monthly for life.

Other vitamin B12 deficiencies: Similar initial dosing may be used depending on severity, followed by oral supplementation if absorption is adequate.

Vitamin B12 absorption test (Schilling test): Single flushing dose of 1000 mcg.

Parenteral products must be inspected for particulate matter and discoloration before use.

Known hypersensitivity to cobalt or vitamin B12 is a contraindication.

• Anaphylactic shock and fatal reactions have been reported; intradermal testing is recommended for patients suspected to be sensitive.
• Patients with early Leber's disease receiving cyanocobalamin may suffer severe optic nerve damage.
• Rapid correction of severe megaloblastic anemia may cause hypokalemia and sudden death; potassium levels must be monitored closely.
• Contains benzyl alcohol, linked to fatal "Gasping Syndrome" in premature infants.
• Contains aluminum which may accumulate to toxic levels during prolonged parenteral use in patients with impaired kidney function, especially premature neonates.

• Common or mild: Transient diarrhea, itching, temporary skin rash, sensation of body swelling.
• Serious reactions: Anaphylactic shock and death following parenteral administration, pulmonary edema, congestive heart failure early after treatment, peripheral vascular thrombosis, polycythemia vera.

• Antibiotics, methotrexate, and pyrimethamine can interfere with vitamin B12 and folic acid blood tests.
• Colchicine, para-aminosalicylic acid, and chronic heavy alcohol intake may cause vitamin B12 malabsorption.
• Some drugs may cause malabsorption requiring adjustment or treatment revision.

Pregnancy: No adequate controlled studies exist, but vitamin B12 is essential and requirements increase during pregnancy. Recommended intake is 4 mcg daily.

Lactation: Vitamin B12 is excreted in human milk; recommended intake is 4 mcg daily.

Pediatrics: Intake should follow recommended amounts of 0.5 to 3 mcg daily per National Academy guidelines.

No overdose cases have been reported.

Store at 20° to 25°C (68° to 77°F) controlled room temperature. Protect from light. Use only if solution is clear and seal intact.