What the FDA labels say about taking them together
Aprepitant and warfarin
Aprepitant's FDA label of July 5, 2024 names warfarin in its drug interactions section, and warfarin's label names aprepitant too. The aprepitant label: “Clinical Impact; Decreased warfarin exposure and decreased prothrombin time (INR).”
Check it at the source: the aprepitant FDA label on DailyMed (effective July 5, 2024, Merck Sharp & Dohme LLC); the warfarin FDA label on DailyMed (effective May 29, 2026, Amneal Pharmaceuticals LLC).
What does the aprepitant label say about warfarin?
Aprepitant label, drug interactionsClinical Impact; Decreased warfarin exposure and decreased prothrombin time (INR) [see, ].
Aprepitant label, warnings and precautionsSee Full Prescribing Information for recommendations regarding contraindications, risk of adverse reactions, and dosage adjustments of EMEND and concomitant drugs. ( 4 , 5.1 , 7.1 , 7.2 ) Warfarin (a CYP2C9 substrate):
Cinvanti label (Heron Therapeutics, Inc., April 1, 2026), warnings and precautionsCoadministration of CINVANTI with warfarin, a CYP2C9 substrate, may result in a clinically significant decrease in the International Normalized Ratio (INR) of prothrombin time [see Clinical Pharmacology (12.3) ].
Aponvie label (Heron Therapeutics, Inc., April 1, 2026), warnings and precautionsAprepitant is a substrate, weak-to-moderate inhibitor, and inducer of CYP3A4; see full prescribing information. ( 5.2 , 7.2 ) Warfarin (a CYP2C9 substrate):
Source: FDA drug label (Cinvanti, NDA209296), Heron Therapeutics, Inc., effective April 1, 2026 (SPL set 4c218d3a-a508-4abc-9ed8-a6e8e191d1b4), via openFDA
Source: FDA drug label (Aponvie, NDA216457), Heron Therapeutics, Inc., effective April 1, 2026 (SPL set d1b111eb-659a-496b-a86a-8f0fa370f147), via openFDA
Source: FDA drug label (EMEND), NDA021549 (Msd), as published by Merck Sharp & Dohme LLC, effective July 5, 2024 (SPL set 696f9e80-9cae-403b-de9e-078343ce4713), via openFDA; the full label on DailyMed
What does the warfarin label say about aprepitant?
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
| Aprepitant | Warfarin | |
|---|---|---|
| Labeled for | Nausea and vomiting | Blood clots (DVT and PE), Atrial fibrillation |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $46.42 per capsule 40 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