Cyanocobalamin (B-12) Injection Dosing and Supply Information
The recommended dose for cyanocobalamin (B-12) injection is 1,000 mcg intramuscularly daily for days 1-10, followed by monthly maintenance injections of 1,000 mcg. 1
Dosing Recommendations
Initial Treatment Dosing
- For vitamin B12 deficiency:
Maintenance Dosing
- 1,000 mcg intramuscularly once monthly 1, 2
- Higher dosage (1,000 mcg vs 100 mcg) provides better vitamin retention with no disadvantage in cost or toxicity 2
Route of Administration
- Intramuscular (IM) or subcutaneous (SC) administration only 3
- Important: Cyanocobalamin should not be given intravenously as there is little opportunity for liver storage due to rapid excretion in urine 1
How Supplied
Cyanocobalamin Injection, USP is available as 1,000 mcg/mL in the following packaging options 3:
- 1 mL single-dose vials (boxes of 25)
- 10 mL multiple-dose vials (boxes of 10)
- 30 mL multiple-dose vials (boxes of 10 or single vial)
Storage Requirements
- Store at 20° to 25°C (68° to 77°F)
- Excursions permitted between 15° to 30°C (59° to 86°F)
- PROTECT FROM LIGHT 3
Alternative Oral Therapy Considerations
While the question specifically asks about injection dosing, it's worth noting that recent evidence supports oral supplementation as an effective alternative in many cases:
- For patients without severe malabsorption: Oral cyanocobalamin 2,000 mcg daily has been shown to be effective 1
- High-dose oral therapy (1,000 mcg daily) has been demonstrated effective even in conditions with impaired absorption such as pernicious anemia 4 and Crohn's disease 5
Clinical Pearls
- The 1,000 mcg dose is significantly higher than the recommended dietary allowance of approximately 3 mcg daily, but this higher dose is necessary for effective treatment 6
- Before committing patients to lifelong injection therapy, consider testing their ability to absorb oral vitamin B12, as many patients previously on injection therapy may not actually require it 7
- Multiple dose vials contain benzyl alcohol as a preservative 3
By following these dosing guidelines and properly storing the medication, clinicians can effectively treat vitamin B12 deficiency while optimizing patient outcomes.