What the FDA labels say about taking them together
Amiodarone and quinidine
Amiodarone's FDA label of December 9, 2025 names quinidine in its drug interactions section, and quinidine's label names amiodarone too. The amiodarone label: “Reserve concomitant use for patients who are unresponsive to a single agent. Antiarrhythmic metabolism inhibited by amiodarone. Initiate antiarrhythmic at a lower than usual dose and monitor patient carefully. …”
Check it at the source: the amiodarone FDA label on DailyMed (effective December 9, 2025, Chartwell RX, LLC); the quinidine FDA label on DailyMed (effective February 1, 2018, Sun Pharmaceutical Industries, Inc.).
What does the amiodarone label say about quinidine?
Amiodarone label, drug interactionsConcomitant Drug/Class/Name: Antiarrhythmics; Examples: quinidine, procainamide, flecainide; Clinical Comment: Reserve concomitant use for patients who are unresponsive to a single agent. Antiarrhythmic metabolism inhibited by amiodarone. Initiate antiarrhythmic at a lower than usual dose and monitor patient carefully. Reduce dose levels of previously administered antiarrhythmic by 30 to 50% for several days after transitioning to oral amiodarone. Evaluate continued need for antiarrhythmic.
Source: FDA drug label (Amiodarone Hydrochloride), Chartwell RX, LLC, effective December 9, 2025 (SPL set 5520f11d-968d-4f4f-bf57-d14369c0d746), via openFDA; the full label on DailyMed
What does the quinidine label say about amiodarone?
Quinidine label, drug interactionsBy pharmacokinetic mechanisms that are not well understood, quinidine levels are increased by coadministration of amiodarone or cimetidine.
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
| Amiodarone | Quinidine | |
|---|---|---|
| Labeled for | n/a | Atrial fibrillation |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $0.122 per tablet 200 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