What the FDA labels say about taking them together
Darifenacin and diltiazem
Darifenacin's FDA label of February 10, 2026 names diltiazem in its drug interactions section; the diltiazem labels PlainMeds reads (4) do not name darifenacin. The darifenacin label: “No dosing adjustments are recommended in the presence of moderate CYP3A4 inhibitors.”
Check it at the source: the darifenacin FDA label on DailyMed (effective February 10, 2026, Torrent Pharmaceuticals Limited); the diltiazem FDA label on DailyMed (effective August 7, 2026, Bausch Health US, LLC).
What does the darifenacin label say about diltiazem?
Darifenacin label, drug interactionsNo dosing adjustments are recommended in the presence of moderate CYP3A4 inhibitors (for example, erythromycin, fluconazole, diltiazem and verapamil) [see Dosage and Administration (2) and Clinical Pharmacology (12.3)].
Source: FDA drug label (Darifenacin), Torrent Pharmaceuticals Limited, effective February 10, 2026 (SPL set e84f1ae3-b9a2-4a15-a299-c75373891cc1), via openFDA; the full label on DailyMed
What does the diltiazem label say about darifenacin?
Diltiazem's label (effective August 7, 2026) and its 3 other brand-application labels do not name darifenacin in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (TIAZAC EXTENDED RELEASE), Bausch Health US, LLC, effective August 7, 2026 (SPL set c567fe7e-887e-4291-a0d1-2dd3f25cbf25), 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
| Darifenacin | Diltiazem | |
|---|---|---|
| Labeled for | Overactive bladder | High blood pressure, Angina, Atrial fibrillation |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.432 per tablet 15 mg tablet | $0.144 per capsule 24h ER(cd) 120 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