What the FDA labels say about taking them together
Carbamazepine and folic acid
Folic acid's FDA label (Folic Acid) of February 11, 2026 names carbamazepine in its drug interactions section; the carbamazepine labels PlainMeds reads (3) do not name folic acid. The folic acid label: “Enzyme-inducing anticonvulsants such as phenytoin, primidone, carbamazepine, phenobarbital, and the broader anticonvulsant class increase hepatic folate metabolism, inhibit intestinal folate-processing enzymes, raise …”
Check it at the source: the carbamazepine FDA label on DailyMed (effective August 20, 2026, Novartis Pharmaceuticals Corporation); the folic acid FDA label on DailyMed (effective July 24, 2026, Rising Pharma Holdings, Inc.).
What does the carbamazepine label say about folic acid?
Carbamazepine's label (effective August 20, 2026) and its 2 other brand-application labels do not name folic acid in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Tegretol), Novartis Pharmaceuticals Corporation, effective August 20, 2026 (SPL set 8d409411-aa9f-4f3a-a52c-fbcb0c3ec053), via openFDA; the full label on DailyMed
What does the folic acid label say about carbamazepine?
Folic Acid label (Ayurax, LLC, February 11, 2026), drug interactionsEnzyme-inducing anticonvulsants such as phenytoin, primidone, carbamazepine, phenobarbital, and the broader anticonvulsant class increase hepatic folate metabolism, inhibit intestinal folate-processing enzymes, raise gastrointestinal pH, or displace folate from serum proteins, collectively leading to decreased folate availability.
Source: FDA drug label (Folic Acid, NDA216395), Ayurax, LLC, effective February 11, 2026 (SPL set 96618bf8-6c03-4df3-9896-b7ef27ca392a), via openFDA
Source: FDA drug label (Folic Acid), Rising Pharma Holdings, Inc., effective July 24, 2026 (SPL set 0baa10dd-6d1d-4946-8236-566451132da3), via openFDA; the full label on DailyMed
These are the labels' own sentences. PlainMeds does not grade interactions; a pharmacist or prescriber can say what they mean for one person's medicines.
Both medicines on the record
| Carbamazepine | Folic acid | |
|---|---|---|
| Labeled for | Bipolar disorder, Seizures and epilepsy | n/a |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $0.119 per tablet 200 mg tablet | $0.0201 per tablet 1 mg tablet |
| Shortage now | A presentation being discontinued | No current entry |
Source: FDA NDC Directory, CMS NADAC of October 7, 2026 and the FDA Drug Shortage Database (FDA files October 8, 2026)
What next?
- Check more medicines together
- up to five at once