What the FDA labels say about taking them together
Quinidine and vardenafil
Vardenafil's FDA label of January 5, 2026 names quinidine in its warnings and precautions section; the quinidine label PlainMeds reads does not name vardenafil. The vardenafil label: “Patients taking Class 1A or Class III antiarrhythmic medications or those with congenital QT prolongation, should avoid using vardenafil.”
Check it at the source: the quinidine FDA label on DailyMed (effective February 1, 2018, Sun Pharmaceutical Industries, Inc.); the vardenafil FDA label on DailyMed (effective January 5, 2026, Zydus Pharmaceuticals USA Inc.).
What does the quinidine label say about vardenafil?
Quinidine's label (effective February 1, 2018) does not name vardenafil 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
What does the vardenafil label say about quinidine?
Vardenafil label, warnings and precautionsPatients taking Class 1A (for example. quinidine, procainamide) or Class III (for example, amiodarone, sotalol) antiarrhythmic medications or those with congenital QT prolongation, should avoid using vardenafil.
Source: FDA drug label (VARDENAFIL), Zydus Pharmaceuticals USA Inc., effective January 5, 2026 (SPL set 5876e062-e604-42a7-99c3-5da30b8dac06), 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
| Quinidine | Vardenafil | |
|---|---|---|
| Labeled for | Atrial fibrillation | Erectile dysfunction |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $4.92 per tablet 324 mg tablet | $2.79 per tablet 20 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