What the FDA labels say about taking them together
Toremifene and warfarin
Toremifene's FDA label of November 13, 2024 names warfarin in its drug interactions section; the warfarin label PlainMeds reads does not name toremifene. The toremifene label: “… should be avoided. CYP2C9 substrates with a narrow therapeutic index such as warfarin or phenytoin with FARESTON should be used with caution and require careful monitoring.”
Check it at the source: the toremifene FDA label on DailyMed (effective November 13, 2024, Kyowa Kirin, Inc.); the warfarin FDA label on DailyMed (effective May 29, 2026, Amneal Pharmaceuticals LLC).
What does the toremifene label say about warfarin?
Toremifene label, drug interactionsDRUG INTERACTIONS Drugs that decrease renal calcium excretion, e.g., thiazide diuretics, may increase the risk of hypercalcemia in patients receiving FARESTON. ( 7.1 ) Agents that prolong QT should be avoided. ( 7.2 ) Coadministration with a strong CYP3A4 inducer may result in a relevant decrease in FARESTON exposure and should be avoided. ( 7.3 ) Coadministration with a strong CYP3A4 inhibitor can result in a relevant increase in FARESTON exposure and should be avoided. ( 7.4 ) CYP2C9 substrates with a narrow therapeutic index such as warfarin or phenytoin with FARESTON should be used with caution and require careful monitoring.
Source: FDA drug label (Fareston), Kyowa Kirin, Inc., effective November 13, 2024 (SPL set 2cab8dd1-3a10-48e6-86ce-0e5275ed49e5), via openFDA; the full label on DailyMed
What does the warfarin label say about toremifene?
Warfarin's label (effective May 29, 2026) does not name toremifene 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
| Toremifene | Warfarin | |
|---|---|---|
| Labeled for | Breast cancer | Blood clots (DVT and PE), Atrial fibrillation |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $19.60 per tablet 60 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