What the FDA labels say about taking them together
Fesoterodine and itraconazole
Fesoterodine's FDA label of April 7, 2026 names itraconazole in its drug interactions section, and itraconazole's label names fesoterodine too. The itraconazole label: “Fesoterodine Patients with moderate to severe renal or hepatic impairment: Contraindicated during and 2 weeks after TOLSURA treatment.”
Check it at the source: the fesoterodine FDA label on DailyMed (effective April 7, 2026, Pfizer Laboratories Div Pfizer Inc); the itraconazole FDA label on DailyMed (effective July 13, 2026, Janssen Pharmaceuticals, Inc.).
What does the fesoterodine label say about itraconazole?
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
What does the itraconazole label say about fesoterodine?
Itraconazole label, boxed warningCoadministration with colchicine, fesoterodine and solifenacin is contraindicated in subjects with varying degrees of renal or hepatic impairment.
Itraconazole label, contraindicationsIn addition, coadministration with colchicine, fesoterodine, and solifenacin is contraindicated in subjects with varying degrees of renal or hepatic impairment, and coadministration with eliglustat is contraindicated in subjects that are poor or intermediate metabolizers of CYP2D6 and in subjects taking strong or moderate CYP2D6 inhibitors. (See PRECAUTIONS:
Itraconazole label, drug interactionsFesoterodine Patients with moderate to severe renal or hepatic impairment: Contraindicated during and 2 weeks after SPORANOX ® treatment.
Tolsura label (Mayne Pharma Commercial LLC, April 23, 2025), boxed warningDrug Interactions Co-administration of certain drugs that are metabolized by human CYP3A4 enzymes are contraindicated with TOLSURA because plasma concentrations of such drugs are increased. ( 4.1 , 5.5 , 7.1 ) Co-administration with colchicine, fesoterodine and solifenacin is contraindicated in subjects with varying degrees of renal or hepatic impairment. ( 4.1 , 7.1 ) Co-administration with eliglustat is contraindicated in poor or intermediate metabolizers of CYP2D6 and in subjects taking strong or moderate CYP2D6 inhibitors. …
Source: FDA drug label (Tolsura, NDA208901), Mayne Pharma Commercial LLC, effective April 23, 2025 (SPL set 306352d1-9d5a-49ad-b72d-893b99546861), via openFDA
Source: FDA drug label (SPORANOX), Janssen Pharmaceuticals, Inc., effective July 13, 2026 (SPL set a4d555fa-787c-40fb-bb7d-b0d4f7318fd0), 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 | Itraconazole | |
|---|---|---|
| Labeled for | Overactive bladder | Fungal infections |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $0.794 per tablet 4 mg tablet | $0.910 per capsule 100 mg capsule |
| Shortage now | No current entry | A presentation being discontinued |
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