What the FDA labels say about taking them together
Fosamprenavir and ketoconazole
Fosamprenavir's FDA label of September 15, 2023 names ketoconazole in its drug interactions section; the ketoconazole label PlainMeds reads does not name fosamprenavir. The fosamprenavir label: “Increase monitoring for adverse events. Fosamprenavir: Dose reduction of ketoconazole or itraconazole may be needed for patients receiving more than 400 mg ketoconazole or itraconazole per day. …”
Check it at the source: the fosamprenavir FDA label on DailyMed (effective September 15, 2023, Mylan Pharmaceuticals Inc.); the ketoconazole FDA label on DailyMed (effective January 28, 2026, E. Fougera & Co. a division of Fougera Pharmaceuticals, LLC).
What does the fosamprenavir label say about ketoconazole?
Fosamprenavir label, drug interactionsConcomitant Drug Class/Drug Name: Antifungals: Ketoconazole, itraconazole; Effect on Concentration of Amprenavir or Concomitant Drug: ↑ Ketoconazole ↑ Itraconazole; Clinical Comment: Increase monitoring for adverse events. Fosamprenavir: Dose reduction of ketoconazole or itraconazole may be needed for patients receiving more than 400 mg ketoconazole or itraconazole per day. Fosamprenavir/ritonavir: High doses of ketoconazole or itraconazole (greater than 200 mg/day) are not recommended.
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 ketoconazole label say about fosamprenavir?
Ketoconazole's label (effective January 28, 2026) does not name fosamprenavir in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (ketoconazole), E. Fougera & Co. a division of Fougera Pharmaceuticals, LLC, effective January 28, 2026 (SPL set cad7c647-34a9-4e4e-83b3-8d78e58f588f), 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 | Ketoconazole | |
|---|---|---|
| Labeled for | HIV | Fungal infections |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | n/a | $0.249 per gram 2% cream |
| 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