Nascobal, Physicians EZ Use B-12, Vitamin Deficiency -b12

Written by Amber Watson, PharmD
Medically reviewed by Dena Westphalen, PharmD
Updated on June 27, 2023

This article describes cyanocobalamin’s uses, side effects, and more. You’ll also find some coupon options to help save on the cost of cyanocobalamin.

The Food and Drug Administration (FDA) approves prescription drugs such as cyanocobalamin for certain conditions. Approved uses for cyanocobalamin are described below.

Use for low blood levels of vitamin B12

Doctors may prescribe cyanocobalamin to treat low blood levels of vitamin B12. It’s used for this purpose in adults and children of all ages. Doctors may prescribe the drug as a long-term or short-term treatment.

With low vitamin B12 levels, your body is unable to absorb enough vitamin B12 from your diet. Certain factors may cause this. A few examples include:

• having a certain kind of anemia (a condition that causes low red blood cell levels)
• having low blood levels of folic acid
• following a vegan diet

Symptoms of low vitamin B12 levels may include:

• fatigue (low energy)
• constipation
• pale-looking skin
• problems with memory and thinking
• irritability or depression

Below you’ll find answers to a few commonly asked questions about cyanocobalamin.

Is cyanocobalamin similar to thiamine, pyridoxine, or methylcobalamin?

Cyanocobalamin is similar to methylcobalamin, but it’s different from thiamine and pyridoxine.

Cyanocobalamin, methylcobalamin, thiamine, and pyridoxine are kinds of B-complex vitamins. They’re used when your body doesn’t absorb enough of certain B vitamins from your diet. They work by raising your blood levels of certain B vitamins to a typical range.

Cyanocobalamin and methylcobalamin are used to replace vitamin B12. Thiamine is used to replace vitamin B1, while pyridoxine is used to replace vitamin B6.

Your doctor can tell you which vitamin B replacement is best for your condition. If you have more questions about how cyanocobalamin compares with other B vitamins, talk with your doctor or pharmacist.

Can I use cyanocobalamin with folic acid?

Yes, if your doctor recommends it.

Cyanocobalamin is used to treat low blood levels of vitamin B12. This may be caused by certain factors, including having low blood levels of folic acid. If you’re using cyanocobalamin and you have this condition, your doctor may also prescribe a folic acid supplement.

To learn whether you should use cyanocobalamin with folic acid for your specific condition, talk with your doctor.

How does cyanocobalamin work? And how long does it take to start working?

Cyanocobalamin works by increasing the level of vitamin B12 in your blood. This can help your body reach typical levels of vitamin B12.

It may take several weeks for your blood levels of vitamin B12 to get to a healthy range after starting cyanocobalamin treatment. Your doctor will check your vitamin B12 levels with a blood test. They’ll use the test results to help determine whether the drug is working.

If you have questions about what to expect with cyanocobalamin treatment, talk with your doctor or pharmacist.

Cyanocobalamin may cause mild or serious side effects. More common mild side effects of cyanocobalamin and its serious side effects are listed below. This article doesn’t include all possible side effects of the drug. Side effects can vary based on your age, overall health, and any other medications you take.

To learn more about cyanocobalamin’s side effects, ask your doctor or pharmacist. You can also read the prescribing information for cyanocobalamin in the “Article resources” section.

Mild side effects

More common mild side effects reported with cyanocobalamin injection* are listed below.

With many drugs, mild side effects may go away within a few days or a couple of weeks. If the side effects are bothersome, tell your doctor or pharmacist. They may be able to suggest ways to manage them.

Cyanocobalamin’s mild side effects include:

• diarrhea
• itchiness
• temporary skin rash
• swelling all over your body
• mild allergic reaction†

* Cyanocobalamin injections can be given into a muscle or under the skin.
† For details about this side effect, see the “Interactions and warnings for cyanocobalamin” section.

Serious side effects

Serious side effects of cyanocobalamin injection* are listed below.

With many drugs, serious side effects are possible but not common. If you have serious side effects from this drug, call your doctor right away. If you’re having severe symptoms or a medical emergency, call 911 or a local emergency number.

In general, cyanocobalamin’s serious side effects include:

• fluid in the lungs
• heart failure
• blood clots in the arms or legs
• a certain kind of blood cancer
• severe allergic reaction†

* Cyanocobalamin injections can be given into a muscle or under the skin.
† For details about this side effect, see the “Interactions and warnings for cyanocobalamin” section.

Below, you’ll find information about cyanocobalamin’s possible interactions and warnings.

Interactions of cyanocobalamin

Certain things may affect how a drug works. These include getting vaccines, consuming alcohol or certain foods, or taking the drug with other medications. This effect is called a drug interaction.

Before you use cyanocobalamin, ask your doctor to check for possible interactions. Be sure to tell them about any of the following you take or use:

• prescription or over-the-counter drugs
• vitamins, herbs, or supplements

To learn about drug-condition interactions, see the “Warnings for cyanocobalamin” section below.

Warnings for cyanocobalamin

Cyanocobalamin should be used cautiously by certain people.

Cyanocobalamin could cause harm to people with certain health conditions. This effect is called a drug-condition interaction. Other factors can also affect whether cyanocobalamin is a safe option for you.

Ask your doctor about specific warnings for cyanocobalamin, and be sure to tell your doctor about your:

• current health, including any allergies to medications
• past health conditions or surgeries

Allergic reaction

Cyanocobalamin can cause an allergic reaction in some people. Severe allergic reactions are rare but possible.

If you’ve had an allergic reaction to cyanocobalamin or any of its ingredients, your doctor will likely not prescribe cyanocobalamin. They can tell you about medications that are safer options for you.

A mild allergic reaction may cause the following symptoms:

• skin rash
• itchiness
• flushing (temporary warmth, redness, or deepening of skin color)

A severe allergic reaction may cause the following symptoms:

• swelling under your skin, usually in your hands, feet, eyelids, or lips
• swelling of your mouth, throat, or tongue, which can cause breathing problems

If you have an allergic reaction to cyanocobalamin, call your doctor right away. If you have severe symptoms, call 911 or a local emergency number.

Overdose of cyanocobalamin

If you use cyanocobalamin, you should not use more than your doctor prescribes. For some drugs, doing so may lead to harmful effects or overdose.

If you think you’ve used too much cyanocobalamin, call your doctor or pharmacist right away. Or you could call 800-222-1222 to speak with someone at America’s Poison Centers. You can also use its online resource. If you have concerning symptoms, call 911 or a local emergency number immediately. You can also go to the closest emergency room.

Pregnancy or breastfeeding and cyanocobalamin

Information about cyanocobalamin and pregnancy and breastfeeding is described below.

Cyanocobalamin and pregnancy

In general, cyanocobalamin is considered safe to use during pregnancy. That said, ask your doctor about whether they feel it’s safe for you.

Cyanocobalamin and breastfeeding

In general, cyanocobalamin is considered safe to use while breastfeeding. That said, ask your doctor about whether they feel it’s safe for you.

This article describes cyanocobalamin’s uses and side effects, ways to save on cost, and more. Let your doctor know if you have questions about cyanocobalamin or would like more details about it.

Here’s a list of some possible questions you may want to ask your doctor:

• Are there other forms of vitamin B12 that can be used for my condition?
• Should I use cyanocobalamin with any other treatments for my condition?
• Will cyanocobalamin cure my condition?

• Cyanocobalamin- cyanocobalamin injection. (2022). https://nctr-crs.fda.gov/fdalabel/services/spl/set-ids/a66eb3c4-3e1d-4d49-b963-4fa2334cc9b6/spl-doc
• Food and Drug Administration. (2023). Orange Book: Approved drug products with therapeutic equivalence evaluations. https://www.accessdata.fda.gov/scripts/cder/ob/index.cfm

Disclaimer: Optum Perks has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.