What the FDA labels say about taking them together
Omeprazole and warfarin
Omeprazole's FDA label of April 22, 2024 names warfarin in its drug interactions section, and warfarin's label names omeprazole too. The omeprazole label: “Increased INR and prothrombin time in patients receiving PPIs, including omeprazole, and warfarin concomitantly. Increases in INR and prothrombin time may lead to abnormal bleeding and even death.”
Check it at the source: the omeprazole FDA label on DailyMed (effective April 22, 2024, Apotex Corp); the warfarin FDA label on DailyMed (effective May 29, 2026, Amneal Pharmaceuticals LLC).
What does the omeprazole label say about warfarin?
Omeprazole label, drug interactionsClinical Impact: Increased INR and prothrombin time in patients receiving PPIs, including omeprazole, and warfarin concomitantly. Increases in INR and prothrombin time may lead to abnormal bleeding and even death. Intervention: Monitor INR and prothrombin time and adjust the dose of warfarin, if needed, to maintain target INR range.
Source: FDA drug label (Omeprazole), Apotex Corp, effective April 22, 2024 (SPL set b83329ac-a65e-b3af-a3fb-c5a6c740e5e7), via openFDA; the full label on DailyMed
What does the warfarin label say about omeprazole?
Warfarin label, drug interactions… disulfiram, enoxacin, famotidine, fluvoxamine, methoxsalen, mexiletine, norfloxacin, oral contraceptives, phenylpropanolamine, propafenone, propranolol, terbinafine, thiabendazole, ticlopidine, verapamil, zileuton montelukast, moricizine, omeprazole, phenobarbital, phenytoin, cigarette smoking CYP3A4 alprazolam, amiodarone, amlodipine, amprenavir, aprepitant, atorvastatin, atazanavir, bicalutamide, cilostazol, cimetidine, ciprofloxacin, clarithromycin, conivaptan, cyclosporine, darunavir/ritonavir, diltiazem, erythromycin, fluconazole, fluoxetine, fluvoxamine, fosamprenavir, imatinib, indinavir, isoniazid, itraconazole, ketoconazole, lopinavir/ritonavir, nefazodone, nelfinavir, nilotinib …
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
| Omeprazole | Warfarin | |
|---|---|---|
| Labeled for | Acid reflux and ulcers | Blood clots (DVT and PE), Atrial fibrillation |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $0.0295 per capsule 20 mg capsule | $0.093 per tablet 2 mg tablet |
| Shortage now | A presentation being discontinued | 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