What are the prescription details for monthly vitamin B12 shots, including needle and syringe specifications?

Prescription Details for Monthly Vitamin B12 Injections

For monthly vitamin B12 injections, prescribe 1000 μg (1 mg) of cyanocobalamin to be administered intramuscularly using a 1-inch, 22-25 gauge needle and a standard 3 mL syringe. 1, 2

Medication Specifications

• Medication: Cyanocobalamin injection, USP
• Concentration: 1000 μg/mL (1 mg/mL)
• Dose: 1000 μg (1 mL) monthly
• Route: Intramuscular (IM)
• Frequency: Once monthly

Needle and Syringe Specifications

• Needle size: 1-inch, 22-25 gauge needle for adults 3
• Syringe: 3 mL standard syringe
• Injection site: Deltoid muscle of the upper arm or anterolateral aspect of the thigh 3

Administration Guidelines

1. Injection technique:

   • Insert needle at a 90-degree angle into the muscle mass 3
   • Aspirate before injection to ensure the needle is not in a blood vessel
   • Inject medication slowly into the muscle

2. Preferred injection sites:

   • Adults: Deltoid muscle of the upper arm (primary site)
   • Alternative: Anterolateral aspect of the thigh
   • Avoid buttocks due to risk of sciatic nerve injury and reduced absorption 3

3. Sterile technique:

   • Use sterile, disposable needles and syringes
   • Wash hands before administration
   • Clean injection site with alcohol swab
   • Properly dispose of needles in puncture-proof containers 3

Monitoring Recommendations

• Check B12 levels at 3,6, and 12 months in the first year after starting monthly injections 1
• Once levels have stabilized, annual monitoring is sufficient 1
• Consider measuring both serum B12 and functional markers like methylmalonic acid for comprehensive assessment 1

Important Considerations

• Higher doses (1000 μg) are recommended over lower doses (100 μg) as they provide better retention with no increase in cost or toxicity 2
• For severe deficiency, consider initial loading doses: 5-6 biweekly injections of 1000 μg, followed by monthly maintenance 2
• Methylcobalamin or hydroxocobalamin may be preferred over cyanocobalamin for patients with neurological symptoms 1
• Patients with malabsorption issues (bariatric surgery, ileal resection, pernicious anemia) particularly benefit from the IM route 1, 4

Prescription Example

Rx: Cyanocobalamin injection 1000 μg/mL
Disp: 1 mL vials #12 (twelve)
Sig: Inject 1 mL intramuscularly once monthly
Refills: 12

Supplies:
- 3 mL syringes #12
- 1-inch, 23-gauge needles #12
- Alcohol swabs #12

Remember that untreated vitamin B12 deficiency for more than 3 months may produce permanent degenerative lesions of the spinal cord, emphasizing the importance of consistent monthly administration 1.