Drug interactions
Carbamazepine + Vitamin B12
Severity: Minor
Carbamazepine and Vitamin B12: minor 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
Long-term carbamazepine has been associated with lower serum B12 in some observational studies. The change is usually small and rarely leads to clinical deficiency, though it may matter in patients with other risk factors.
What this interaction means in plain words
Carbamazepine and Vitamin B12 have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Carbamazepine belongs to Central Nervous System; Vitamin B12 belongs to Gastrointestinal Tract.
Why it happens
Mechanism is not established; enzyme induction or altered B12 handling has been proposed.
What to do
Check B12 levels if the patient on long-term carbamazepine has anemia, neuropathy or cognitive symptoms. Supplement only if deficiency is confirmed.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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Other interactions of Vitamin B12
- Chloramphenicol + Vitamin B12 Moderate
- Dichlorphenamide + Vitamin B12 Moderate
- Metformin + Vitamin B12 Moderate
- Neomycin po + Vitamin B12 Moderate
- Aspirin / citric acid / sodium bicarbonate + Vitamin B12 Minor
- Aspirin + Vitamin B12 Minor
Other interactions of Carbamazepine
- Artemether / lumefantrine + Carbamazepine Contraindicated
- Cabotegravir + Carbamazepine Contraindicated
- Carbamazepine + Delamanid Contraindicated
- Carbamazepine + Dienogest / estradiol valerate Contraindicated
- Carbamazepine + Doravirine Contraindicated
- Carbamazepine + Elbasvir / grazoprevir Contraindicated
Frequently asked questions
Can I take Carbamazepine with Vitamin B12?
MediHelp rates the interaction as minor. Carbamazepine and Vitamin B12 have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Long-term carbamazepine has been associated with lower serum B12 in some observational studies. The change is usually small and rarely leads to clinical deficiency, though it may matter in patients with other risk factors.
How serious is the interaction between Carbamazepine and Vitamin B12?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Check B12 levels if the patient on long-term carbamazepine has anemia, neuropathy or cognitive symptoms. Supplement only if deficiency is confirmed.
What other medicines interact with Vitamin B12?
MediHelp also lists interactions of Vitamin B12 with, for example, Chloramphenicol, Dichlorphenamide, Metformin. The full list is on the Vitamin B12 page.
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