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;
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)
Cyanocobalamin dosing information
Usual Adult Dose for Pernicious Anemia:
Initial dose: 100 mcg intramuscularly once a day for 7 days. If there is clinical improvement and a reticulocyte response, 100 mcg intramuscularly once every other day for 7 days, then once every 3 to 4 days for another 2 to 3 weeks is recommended. Most patients require monthly injections of 100 to 1000 mcg intramuscularly for life.
Nasal Spray or Gel:
Alternatively, cyanocobalamin (Nascobal) nasal spray or nasal gel 500 mcg intranasally to one nostril once a week may be administered to patients with pernicious anemia who require maintenance of normal hematologic status following intramuscular vitamin B12 and who have no nervous system involvement. However, if the patient is not adequately maintained with cyanocobalamin nasal, intramuscular vitamin B12 administration must be resumed.
Usual Adult Dose for B12 Nutritional Deficiency:
Oral: 25 to 250 mcg once a day.
Nasal Spray or Gel:
(Nascobal) 500 mcg intranasally in one nostril once a week
(CaloMist) 25 mcg in each nostril once a day (total dose 50 mcg). May be increased to 50 mcg in each nostril once a day.
Usual Adult Dose for Schilling Test:
1 mcg radiolabeled cyanocobalamin orally once after urinary voiding. A 24-hour urinary collection is immediately begun. At 2 hours an injection of cyanocobalamin 1,000 mcg intramuscularly is given to "flush" the patient of absorbed radiolabeled drug. The percentage of radiolabeled B12 excreted in the urine is a measure of how much labeled drug was absorbed. Normally 7% or more of a dose is excreted in 24 hours (< 7% may be considered a positive Schilling test).
Usual Pediatric Dose for Pernicious Anemia:
Neonates and Infants: Intramuscular or Subcutaneous: 0.2 mcg/kg for 2 days, followed by 1000 mcg/day for 2 to 7 days; maintenance: 100 mcg/month.
Children: Intramuscular or Subcutaneous: 30 to 50 mcg/day for 2 or more weeks (to a total dose of 1000 mcg), then follow with 100 mcg/month.
Usual Pediatric Dose for B12 Nutritional Deficiency:
Intramuscular or Subcutaneous: Initial: 0.2 mcg/kg for 2 days followed by 1000 mcg/day for 2 to 7 days followed by 100 mcg/week for a month or 100 mcg/day for 10 to 15 days (total dose of 1 to 1.5 mg), then once or twice weekly for several months. May taper to 60 mcg every month. For malabsorptive causes of B12 deficiency, monthly maintenance doses of 100 mcg have been recommended.
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.
More about cyanocobalamin
- Cyanocobalamin (b12)
- Cyanocobalamin (b12) chewable tablets
- Cyanocobalamin (b12) controlled-release tablets
- Cyanocobalamin (b12) spray
- Cyanocobalamin (b12) sublingual tablets
- More (5) »
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Where can I get more information?
- Your pharmacist can provide more information about oral cyanocobalamin.
- 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.
- Disclaimer: Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.
Copyright 1996-2012 Cerner Multum, Inc. Version: 5.08.
Date modified: January 10, 2017
Last reviewed: March 06, 2014