Drug
Cyanocobalamin
Pronounced
"SYE-an-oh-koe-BAL-a-min"
Side Effects
Pain/redness at the injection site, mild diarrhea, itching, or a feeling of swelling all over the body may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.
Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.
This medication may cause low potassium levels in the blood (hypokalemia). Tell your doctor right away if any of these serious side effects occur: muscle cramps, weakness, irregular heartbeat.
People who have a rare blood disorder (polycythemia vera) may rarely have symptoms related to this disorder while taking cyanocobalamin. Get medical help right away if any of these very serious symptoms occur: chest pain (especially with shortness of breath), weakness on one side of the body, sudden vision changes, trouble speaking.
Get medical help right away if you have any very serious side effects, including: symptoms of heart failure (such as shortness of breath, swelling ankles/feet, unusual tiredness, unusual/sudden weight gain).
A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.
This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.
In the US -
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.
In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
Precautions
Before using cyanocobalamin, tell your doctor or pharmacist if you are allergic to it; or to cobalt; or if you have any other allergies. Your doctor may recommend that you receive a smaller test dose before starting your regular dose. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.
Before using this medication, tell your doctor or pharmacist your medical history, especially of: low potassium blood levels (hypokalemia), gout, kidney disease, a certain blood disorder (polycythemia vera), a certain eye disease (Leber's disease), other vitamin/mineral deficiencies (especially folic acid and iron).
Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).
During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.
Based on information from related drugs, this medication may pass into breast milk. Consult your doctor before breastfeeding.