What the FDA labels say about taking them together
Fosaprepitant and warfarin
Fosaprepitant's FDA label of July 29, 2026 names warfarin in its drug interactions section; the warfarin label PlainMeds reads does not name fosaprepitant. The fosaprepitant label: “Clinical Impact; Decreased warfarin exposure and decreased prothrombin time (INR).”
Check it at the source: the fosaprepitant FDA label on DailyMed (effective July 29, 2026, AVYXA Pharma, LLC); the warfarin FDA label on DailyMed (effective May 29, 2026, Amneal Pharmaceuticals LLC).
What does the fosaprepitant label say about warfarin?
Fosaprepitant label, drug interactionsClinical Impact; Decreased warfarin exposure and prolongation of prothrombin time (INR) [see, ].
Fosaprepitant label, warnings and precautionsCoadministration of fosaprepitant 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) ].
Focinvez label (Steriscience Specialties Private Limited, March 30, 2026), drug interactionsClinical Impact; Decreased warfarin exposure and decreased prothrombin time (INR) [see Warnings and Precautions () and Clinical Pharmacology ()].
Source: FDA drug label (Emend, NDA022023), Merck Sharp & Dohme LLC, effective February 20, 2026 (SPL set 8d66803a-6811-4c29-9c57-e16acfa87f21), via openFDA
Source: FDA drug label (NAVITRUX), AVYXA Pharma, LLC, effective July 29, 2026 (SPL set a41b7c3a-1376-43a7-b5b9-6ba2eba1e169), via openFDA; the full label on DailyMed
What does the warfarin label say about fosaprepitant?
Warfarin's label (effective May 29, 2026) does not name fosaprepitant in these sections. A label lists what its studies and reports found; it is not a complete list.
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
| Fosaprepitant | Warfarin | |
|---|---|---|
| Labeled for | n/a | Blood clots (DVT and PE), Atrial fibrillation |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | n/a | $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