What the FDA labels say about taking them together
Propafenone and quinidine
Propafenone's FDA label of September 1, 2025 names quinidine in its drug interactions section, and quinidine's label names propafenone too. The propafenone label: “Avoid the use of propafenone with Class IA and III antiarrhythmic agents.”
Check it at the source: the propafenone FDA label on DailyMed (effective September 1, 2025, Strides Pharma Science Limited); the quinidine FDA label on DailyMed (effective February 1, 2018, Sun Pharmaceutical Industries, Inc.).
What does the propafenone label say about quinidine?
Propafenone label, drug interactionsSmall doses of quinidine completely inhibit the CYP2D6 hydroxylation metabolic pathway, making all patients, in effect, slow metabolizers [see Clinical Pharmacology (12.3)].
Propafenone label, warnings and precautionsAvoid the use of propafenone with Class IA and III antiarrhythmic agents (including quinidine and amiodarone).
Source: FDA drug label (PROPAFENONE HYDROCHLORIDE), Strides Pharma Science Limited, effective September 1, 2025 (SPL set c65253ab-937f-4982-b841-69c2b9f9ccdb), via openFDA; the full label on DailyMed
What does the quinidine label say about propafenone?
Quinidine label, drug interactionsNon-interactions of quinidine with other drugs: Quinidine has no clinically significant effect on the pharmacokinetics of diltiazem, flecainide, mephenytoin, metoprolol, propafenone, propranolol, quinine, timolol, or tocainide.
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
| Propafenone | Quinidine | |
|---|---|---|
| Labeled for | Atrial fibrillation | Atrial fibrillation |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $0.115 per tablet 150 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