What the FDA labels say about taking them together
Carbamazepine and fesoterodine
Fesoterodine's FDA label of April 7, 2026 names carbamazepine in its drug interactions section; the carbamazepine labels PlainMeds reads (3) do not name fesoterodine. The fesoterodine label: “No dosing adjustments are recommended in the presence of CYP3A4 inducers, such as rifampin and carbamazepine.”
Check it at the source: the carbamazepine FDA label on DailyMed (effective August 20, 2026, Novartis Pharmaceuticals Corporation); the fesoterodine FDA label on DailyMed (effective April 7, 2026, Pfizer Laboratories Div Pfizer Inc).
What does the carbamazepine label say about fesoterodine?
Carbamazepine's label (effective August 20, 2026) and its 2 other brand-application labels do not name fesoterodine 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 fesoterodine label say about carbamazepine?
Fesoterodine label, drug interactionsNo dosing adjustments are recommended in the presence of CYP3A4 inducers, such as rifampin and carbamazepine.
Source: FDA drug label (Toviaz), Pfizer Laboratories Div Pfizer Inc, effective April 7, 2026 (SPL set 5be745f0-8ae7-4c3c-9962-37d6263326f1), 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 | Fesoterodine | |
|---|---|---|
| Labeled for | Bipolar disorder, Seizures and epilepsy | Overactive bladder |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $0.119 per tablet 200 mg tablet | $0.794 per tablet 4 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