What the FDA labels say about taking them together
Clarithromycin and fesoterodine
Fesoterodine's FDA label of April 7, 2026 names clarithromycin in its drug interactions section; the clarithromycin label PlainMeds reads does not name fesoterodine. The fesoterodine label: “Doses of Toviaz greater than 4 mg are not recommended in adult patients taking strong CYP3A4 inhibitors, such as ketoconazole, itraconazole, and clarithromycin.”
Check it at the source: the clarithromycin FDA label on DailyMed (effective April 9, 2026, Solaris Pharma Corporation); the fesoterodine FDA label on DailyMed (effective April 7, 2026, Pfizer Laboratories Div Pfizer Inc).
What does the clarithromycin label say about fesoterodine?
Clarithromycin's label (effective April 9, 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 (Clarithromycin), Solaris Pharma Corporation, effective April 9, 2026 (SPL set 4d42821d-ce7a-7d64-e063-6294a90a0875), via openFDA; the full label on DailyMed
What does the fesoterodine label say about clarithromycin?
Fesoterodine label, drug interactionsDoses of Toviaz greater than 4 mg are not recommended in adult patients taking strong CYP3A4 inhibitors, such as ketoconazole, itraconazole, and clarithromycin [see Dosage and Administration (2.5) ].
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
| Clarithromycin | Fesoterodine | |
|---|---|---|
| Labeled for | Bacterial infections, Acid reflux and ulcers | Overactive bladder |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.466 per tablet 500 mg tablet | $0.794 per tablet 4 mg tablet |
| Shortage now | No current entry | 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