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Cyanocobalamin

Generic Name: cyanocobalamin (oral) (sye AN oh koe BAL a min)
Brand Name: B-12, Eligen B12, Vitamin B12
Dosage Forms: oral tablet (100 mcg; 1000 mcg; 1000 mcg with salcaprozate sodium; 250 mcg; 2500 mcg; 50 mcg; 500 mcg); oral tablet, extended release (1000 mcg; 5000 mcg); sublingual liquid (3000 mcg/mL); sublingual lozenge (1000 mcg; 6000 mcg); sublingual tablet (1000 mcg; 2500 mcg; 500 mcg; 5000 mcg)

Medically reviewed by Drugs.com on Jan 11, 2021. Written by Cerner Multum.

What is oral cyanocobalamin?

Cyanocobalamin is a form of vitamin B12. Vitamin B12 is important for growth, cell reproduction, blood formation, and protein and tissue synthesis.

Cyanocobalamin is used to treat vitamin B12 deficiency in people with pernicious anemia or other conditions such as folic acid deficiency, pregnancy, thyroid problems, stomach and intestinal disorders, bleeding, liver or kidney disease, parasite infection, or cancer.

Cyanocobalamin may also be used for purposes not listed in this medication guide.

Warnings

You should not use cyanocobalamin if you are allergic to cobalt, or if you have Leber's disease.

Before taking this medicine

You should not use this medicine if you are allergic to cobalt or if you have Leber's disease. Cyanocobalamin can lead to optic nerve damage (and possibly blindness) in people with Leber's disease.

Ask a doctor or pharmacist if this medicine is safe to use if you have ever had:

  • low levels of calcium or potassium in your blood;

  • heart disease;

  • a stroke;

  • a bleeding or blood clotting disorder such as hemophilia;

  • diabetes;

  • an iron or folic acid deficiency;

  • kidney disease; or

  • any condition that makes it hard for your body to absorb nutrients from food (malabsorption).

Ask a doctor before using this medicine if you are pregnant or breastfeeding.

Do not give this medicine to a child without medical advice.

How should I take oral cyanocobalamin?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

Carefully follow instructions about whether to take your cyanocobalamin with or without food.

Your dose needs may change if you become pregnant, if you breastfeed, or if you eat a vegetarian diet. Tell your doctor about any changes in your diet or medical condition.

Swallow the extended-release tablet whole and do not crush, chew, or break it. Take with a full glass of water.

Do not swallow a lozenge or sublingual tablet whole. Allow it to dissolve in your mouth without chewing. Cyanocobalamin sublingual tablet or liquid should be placed under your tongue.

Pernicious anemia is also treated with folic acid to help maintain red blood cells. However, folic acid will not treat Vitamin B12 deficiency and will not prevent possible damage to the spinal cord. Take all of your medications as directed.

To treat pernicious anemia, you will have to use cyanocobalamin on a regular basis for the rest of your life. Not using the medication can lead to irreversible nerve damage in your spinal cord.

You may need frequent medical tests to help your doctor determine how long to treat you with cyanocobalamin. Using certain other medicines while taking cyanocobalamin may affect the results of these tests.

Store at room temperature away from moisture, heat, and light.

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking oral cyanocobalamin?

Avoid drinking large amounts of alcohol. Heavy drinking can make it harder for your body to absorb cyanocobalamin.

Oral cyanocobalamin side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have:

  • easy bruising or bleeding (nosebleeds, bleeding gums);

  • extreme tiredness;

  • a light-headed feeling, like you might pass out;

  • pale skin, blue lips or fingernails;

  • eye pain, vision problems;

  • headache, ringing in your ears;

  • chest pain or tightness, fasts heartbeats;

  • cough, wheezing, trouble breathing;

  • trouble swallowing;

  • little or no urination;

  • heart problems--swelling, rapid weight gain, feeling short of breath;

  • low potassium level--leg cramps, constipation, irregular heartbeats, fluttering in your chest, increased thirst or urination, numbness or tingling, muscle weakness or limp feeling; or

  • signs of a blood clot in an arm or leg--pain, numbness, coldness, warmth, or pale appearance.

Common side effects may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Cyanocobalamin dosing information

Usual Adult Dose for Pernicious Anemia:

Initial dose: 100 mcg intramuscularly or deep subcutaneous once a day for 6 to 7 days
If clinical improvement and reticulocyte response is seen from the above dosing:
-100 mcg every other day for 7 doses, then:
-100 mcg every 3 to 4 days for 2 to 3 weeks, then:
Maintenance dose: 100 to 1000 mcg monthly
Duration of therapy: Life

Comments:
-Administer concomitant folic acid if needed.
-Chronic treatment should be done with an oral preparation in patients with normal intestinal absorption.

Usual Adult Dose for B12 Nutritional Deficiency:

25 to 2000 mcg orally daily

Usual Adult Dose for Schilling Test:

1000 mcg intramuscularly is the flushing dose

Usual Pediatric Dose for B12 Nutritional Deficiency:

0.5 to 3 mcg daily

What other drugs will affect oral cyanocobalamin?

Other drugs may affect cyanocobalamin, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.