Drug interactions
Chloramphenicol + Vitamin B12
Severity: Moderate
Chloramphenicol and Vitamin B12: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Chloramphenicol can suppress bone marrow, which may delay or blunt the hematologic response to vitamin B12 in patients being treated for pernicious or megaloblastic anemia. The effect is described in case reports and has clinical relevance mainly in deficient patients.
What this interaction means in plain words
Chloramphenicol and Vitamin B12 can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Chloramphenicol belongs to Anti Bacterial; Vitamin B12 belongs to Gastrointestinal Tract.
Why it happens
Chloramphenicol-induced bone marrow suppression counteracts the erythropoietic response to B12 replacement.
What to do
Monitor reticulocyte count and hemoglobin in B12-deficient patients receiving chloramphenicol. Use an alternative antibiotic if the expected hematologic response fails to appear.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Vitamin B12
Other interactions of Chloramphenicol
Frequently asked questions
Can I take Chloramphenicol with Vitamin B12?
MediHelp rates the interaction as moderate. Chloramphenicol and Vitamin B12 can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Chloramphenicol can suppress bone marrow, which may delay or blunt the hematologic response to vitamin B12 in patients being treated for pernicious or megaloblastic anemia. The effect is described in case reports and has clinical relevance mainly in deficient patients.
How serious is the interaction between Chloramphenicol and Vitamin B12?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor reticulocyte count and hemoglobin in B12-deficient patients receiving chloramphenicol. Use an alternative antibiotic if the expected hematologic response fails to appear.
What other medicines interact with Vitamin B12?
MediHelp also lists interactions of Vitamin B12 with, for example, Dichlorphenamide, Metformin, Neomycin po. The full list is on the Vitamin B12 page.
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