What the FDA labels say about taking them together
Darifenacin and quinidine
Darifenacin's FDA label of February 10, 2026 names quinidine in its drug interactions section; the quinidine label PlainMeds reads does not name darifenacin. The darifenacin label: “No dosing adjustments are recommended in the presence of CYP2D6 inhibitors.”
Check it at the source: the darifenacin FDA label on DailyMed (effective February 10, 2026, Torrent Pharmaceuticals Limited); the quinidine FDA label on DailyMed (effective February 1, 2018, Sun Pharmaceutical Industries, Inc.).
What does the darifenacin label say about quinidine?
Darifenacin label, drug interactionsNo dosing adjustments are recommended in the presence of CYP2D6 inhibitors (for example, paroxetine, fluoxetine, quinidine and duloxetine) [see 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 quinidine label say about darifenacin?
Quinidine's label (effective February 1, 2018) does 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 (Quinidine Gluconate), Sun Pharmaceutical Industries, Inc., effective February 1, 2018 (SPL set 5023f053-fcc4-4c2c-aa59-9ec198ad185e), 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 | Quinidine | |
|---|---|---|
| Labeled for | Overactive bladder | Atrial fibrillation |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $0.432 per tablet 15 mg tablet | $4.92 per tablet 324 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