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B-12 Resin

Generic Name: cyanocobalamin (oral) (sye AN oh koe BAL a min)
Brand Name: B-12, Eligen B12, Vitamin B12

What is oral cyanocobalamin?

Cyanocobalamin is a man-made 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 and other conditions.

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

What is the most important information I should know about oral cyanocobalamin?

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

What should I discuss with my healthcare provider before taking oral cyanocobalamin?

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.

To make sure cyanocobalamin is safe for you, tell your doctor if you have:

  • any type of infection;

  • iron or folic acid deficiency;

  • kidney or liver disease; or

  • if you are receiving any medication or treatment that affects bone marrow.

It is not known whether this medicine will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

Cyanocobalamin can pass into breast milk and may harm a nursing baby. Tell your doctor if you are breast-feeding a baby.

How should I take oral cyanocobalamin?

Follow all directions on your prescription label. Do not take this medicine in larger or smaller amounts or for longer than recommended.

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

Take oral cyanocobalamin with a full glass of water.

The sublingual tablet should be placed under your tongue where it will dissolve.

Do not crush, chew, or break an extended-release tablet. Swallow it whole.

To be sure cyanocobalamin is helping your condition, your blood will need to be tested every 3 to 6 months. This will help your doctor determine the correct dose and how long to treat you with cyanocobalamin.

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

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.

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

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

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 while you are being treated with 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:

  • shortness of breath (even with mild exertion), swelling, rapid weight gain;

  • chest pain; or

  • unusual warmth, redness, or pain in an arm or leg.

Common side effects may include:

  • headache, dizziness, weakness;

  • nausea, upset stomach, diarrhea;

  • numbness or tingling;

  • fever;

  • joint pain;

  • swollen tongue; or

  • itching or rash.

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.

See also: Side effects (in more detail)

What other drugs will affect oral cyanocobalamin?

Other drugs may interact with cyanocobalamin, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your health care providers about all medicines you use now 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.

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