What the FDA labels say about taking them together
Fesoterodine and rifampin
Fesoterodine's FDA label of April 7, 2026 names rifampin in its drug interactions section; the rifampin label PlainMeds reads does 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 fesoterodine FDA label on DailyMed (effective April 7, 2026, Pfizer Laboratories Div Pfizer Inc); the rifampin FDA label on DailyMed (effective February 11, 2026, Lupin Pharmaceuticals, Inc.).
What does the fesoterodine label say about rifampin?
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
What does the rifampin label say about fesoterodine?
Rifampin's label (effective February 11, 2026) does 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 (rifampin), Lupin Pharmaceuticals, Inc., effective February 11, 2026 (SPL set b56004f0-f23d-47f6-80c7-39884fccbccc), 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
| Fesoterodine | Rifampin | |
|---|---|---|
| Labeled for | Overactive bladder | n/a |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.794 per tablet 4 mg tablet | $0.679 per capsule 300 mg capsule |
| Shortage now | No current entry | In shortage |
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