What the FDA labels say about taking them together
Amiodarone and warfarin
Amiodarone's FDA label of December 9, 2025 names warfarin in its drug interactions section, and warfarin's label names amiodarone too. The amiodarone label: “Potentiates anticoagulant response and can result in serious or fatal bleeding. Coadministration increases INR by 100% after 3 to 4 days. Reduce warfarin dose by one-third to one-half and monitor INR.”
Check it at the source: the amiodarone FDA label on DailyMed (effective December 9, 2025, Chartwell RX, LLC); the warfarin FDA label on DailyMed (effective May 29, 2026, Amneal Pharmaceuticals LLC).
What does the amiodarone label say about warfarin?
Amiodarone label, drug interactionsConcomitant Drug/Class/Name: Warfarin; Examples: Potentiates anticoagulant response and can result in serious or fatal bleeding. Coadministration increases prothrombin time by 100% after 3 to 4 days. Reduce warfarin dose by one-third to one-half and monitor prothrombin times.
Source: FDA drug label (Nexterone, NDA022325), Baxter Healthcare Corporation, effective April 16, 2024 (SPL set e9108958-b8d7-4fba-87c3-9a32990de551), via openFDA
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 warfarin label say about amiodarone?
Warfarin label, drug interactionsClosely monitor INR if a concomitant drug is a CYP2C9, 1A2, and/or 3A4 inhibitor or inducer. Examples of CYP450 Interactions with Warfarin Enzyme Inhibitors Inducers CYP2C9 amiodarone, capecitabine, cotrimoxazole, etravirine, fluconazole, fluvastatin, fluvoxamine, metronidazole, miconazole, oxandrolone, sulfinpyrazone, tigecycline, voriconazole, zafirlukast aprepitant, bosentan, carbamazepine, phenobarbital, rifampin CYP1A2 acyclovir, allopurinol, caffeine, cimetidine, ciprofloxacin, disulfiram, enoxacin, famotidine, fluvoxamine, methoxsalen, mexiletine, norfloxacin, oral contraceptives, phenylpropanolamine, propafenone, propranolol, terbinafine, thiabendazole, ticlopidine, verapamil …
Source: FDA drug label (Warfarin Sodium), Amneal Pharmaceuticals LLC, effective May 29, 2026 (SPL set 558b7a0d-5490-4c1b-802e-3ab3f1efe760), 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 | Warfarin | |
|---|---|---|
| Labeled for | n/a | Blood clots (DVT and PE), Atrial fibrillation |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $0.122 per tablet 200 mg tablet | $0.093 per tablet 2 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