What the FDA labels say about taking them together
Nifedipine and quinidine
Nifedipine's FDA label of December 24, 2024 names quinidine in its drug interactions section, and quinidine's label names nifedipine too. The quinidine label: “Very rarely, and again by mechanisms not understood, quinidine levels are decreased by coadministration of nifedipine.”
Check it at the source: the nifedipine FDA label on DailyMed (effective December 24, 2024, Aurobindo Pharma Limited); the quinidine FDA label on DailyMed (effective February 1, 2018, Sun Pharmaceutical Industries, Inc.).
What does the nifedipine label say about quinidine?
Nifedipine label, drug interactionsCardiovascular Drugs Antiarrhythmics Quinidine: Quinidine is a substrate of CYP3A and has been shown to inhibit CYP3A in vitro.
Source: FDA drug label (Nifedipine), Aurobindo Pharma Limited, effective December 24, 2024 (SPL set eb70b7ff-f9f0-41d0-901a-f4c04ae9ed46), via openFDA; the full label on DailyMed
What does the quinidine label say about nifedipine?
Quinidine label, drug interactionsVery rarely, and again by mechanisms not understood, quinidine levels are decreased by coadministration of nifedipine.
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
| Nifedipine | Quinidine | |
|---|---|---|
| Labeled for | High blood pressure, Angina | Atrial fibrillation |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $0.130 per tablet 30 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