What the FDA labels say about taking them together
Atazanavir and toremifene
Toremifene's FDA label of November 13, 2024 names atazanavir in its drug interactions section; the atazanavir labels PlainMeds reads (2) do not name toremifene. The toremifene label: “The administration of FARESTON with agents that are strong CYP3A4 inhibitors increase the steady-state concentration in serum and should be avoided.”
Check it at the source: the atazanavir FDA label on DailyMed (effective August 6, 2025, Aurobindo Pharma Limited); the toremifene FDA label on DailyMed (effective November 13, 2024, Kyowa Kirin, Inc.).
What does the atazanavir label say about toremifene?
Atazanavir's label (effective August 6, 2025) and its 1 other brand-application label do 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 (Atazanavir Sulfate), Aurobindo Pharma Limited, effective August 6, 2025 (SPL set 7fbea274-d6b5-4faa-bbf0-05fefab42114), via openFDA; the full label on DailyMed
What does the toremifene label say about atazanavir?
Toremifene label, drug interactionsThe administration of FARESTON with agents that are strong CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, clarithromycin, atazanavir, indinavir, nefazodone, nelfinavir, ritonavir, saquinavir, telithromycin, and voriconazole) increase the steady-state concentration in serum and should be avoided.
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
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
| Atazanavir | Toremifene | |
|---|---|---|
| Labeled for | HIV | Breast cancer |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $2.23 per capsule 300 mg capsule | $19.60 per tablet 60 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