What the FDA labels say about taking them together
Fosamprenavir and mifepristone
Mifepristone's FDA label of September 25, 2025 names fosamprenavir in its drug interactions section; the fosamprenavir label PlainMeds reads does not name mifepristone. The mifepristone label: “Ketoconazole and other strong inhibitors of CYP3A, such as itraconazole, nefazodone, ritonavir, nelfinavir, indinavir, atazanavir, amprenavir and fosamprenavir, clarithromycin, conivaptan, lopinavir /ritonavir …”
Check it at the source: the fosamprenavir FDA label on DailyMed (effective September 15, 2023, Mylan Pharmaceuticals Inc.); the mifepristone FDA label on DailyMed (effective September 25, 2025, Corcept Therapeutics Incorporated).
What does the fosamprenavir label say about mifepristone?
Fosamprenavir's label (effective September 15, 2023) does not name mifepristone in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Fosamprenavir Calcium), Mylan Pharmaceuticals Inc., effective September 15, 2023 (SPL set 3a1424d8-844c-4e24-9ebd-b2c2b61b61a3), via openFDA; the full label on DailyMed
What does the mifepristone label say about fosamprenavir?
Mifepristone label, drug interactionsKetoconazole and other strong inhibitors of CYP3A, such as itraconazole, nefazodone, ritonavir, nelfinavir, indinavir, atazanavir, amprenavir and fosamprenavir, clarithromycin, conivaptan, lopinavir /ritonavir, posaconazole, saquinavir, telithromycin, or voriconazole may increase exposure to mifepristone.
Mifepristone label, warnings and precautionsMifepristone should be used with caution in patients taking ketoconazole and other strong inhibitors of CYP3A, such as itraconazole, nefazodone, ritonavir, nelfinavir, indinavir, atazanavir, amprenavir, fosamprenavir, clarithromycin, conivaptan, lopinavir/ritonavir, posaconazole, saquinavir, telithromycin, or voriconazole, as these could increase the concentration of mifepristone in the blood.
Source: FDA drug label (Mifepristone), Corcept Therapeutics Incorporated, effective September 25, 2025 (SPL set 63c068cd-9370-460f-829b-70e8c7ebe91e), 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
| Fosamprenavir | Mifepristone | |
|---|---|---|
| Labeled for | HIV | n/a |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | n/a | n/a |
| 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