Skip to Content

Vitamin B12 (cyanocobalamin) Disease Interactions

There are 3 disease interactions with Vitamin B12 (cyanocobalamin):


Cyano-/Hydroxocobalamin (Vit B12) (Includes Vitamin B12) ↔ Hypokalemia

Severe Potential Hazard, High plausibility

Applies to: Hypokalemia

Hypokalemia (resulting in death) has occurred during vitamin B12 therapy as a result of increased red blood cell requirements during hematopoiesis. Clinical monitoring and correction of potassium levels prior to and during vitamin B12 therapy is necessary.


  1. "Product Information. Hydro-Cobex (hydroxocobalamin)." Major Pharmaceuticals Inc, Rosemont, IL.
  2. "Product Information. Nascobol (cyanocobalamin nasal)." Schwarz Pharma, Mequon, WI.

Cyano-/Hydroxocobalamin (Vit B12) (Includes Vitamin B12) ↔ Optic Nerve

Severe Potential Hazard, High plausibility

Applies to: Leber's Disease

The use of cyanocobalamin is contraindicated in patients with Leber's disease (hereditary optic nerve atrophy). Cyanocobalamin has induced severe and rapid optic nerve atrophy in patient's with early Leber's disease.


  1. "Product Information. Hydro-Cobex (hydroxocobalamin)." Major Pharmaceuticals Inc, Rosemont, IL.
  2. "Product Information. Nascobol (cyanocobalamin nasal)." Schwarz Pharma, Mequon, WI.

Cyanocobalamin (Includes Vitamin B12) ↔ Renal Impairment

Moderate Potential Hazard, Moderate plausibility

Applies to: Renal Dysfunction

Cyanocobalamin products contain aluminum that may be toxic and may reach toxic levels with prolonged parenteral administration if kidney function is impaired. Premature neonates are particularly at risk because their kidneys are immature, and they require large amounts of calcium and other solutions which also contain aluminum. Research indicates that patients with impaired kidney function, including premature neonates, who receive parenteral levels of aluminum greater than 4-5 mcg/kg/day accumulate aluminum at levels associated with central nervous system and bone toxicity. Caution and monitoring are recommended.

Vitamin B12 (cyanocobalamin) drug Interactions

There are 27 drug interactions with Vitamin B12 (cyanocobalamin)

Drug Interaction Classification

The classifications below are a general guideline only. It is difficult to determine the relevance of a particular drug interaction to any individual given the large number of variables.
Major Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit.
Moderate Moderately clinically significant. Usually avoid combinations; use it only under special circumstances.
Minor Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan.
Unknown No information available.

Do not stop taking any medications without consulting your healthcare provider.

Disclaimer: Every effort has been made to ensure that the information provided by Multum is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. Multum's information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill, knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate that the drug or combination is safe, effective, or appropriate for any given patient. Multum Information Services, Inc. does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. Copyright 2000-2018 Multum Information Services, Inc. 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.