What the FDA labels say about taking them together
Fosamprenavir and nelfinavir
Fosamprenavir's FDA label of September 15, 2023 names nelfinavir in its drug interactions section; the nelfinavir label PlainMeds reads does not name fosamprenavir.
Check it at the source: the fosamprenavir FDA label on DailyMed (effective September 15, 2023, Mylan Pharmaceuticals Inc.); the nelfinavir FDA label on DailyMed (effective December 11, 2025, AGOURON).
What does the fosamprenavir label say about nelfinavir?
Fosamprenavir label, drug interactionsConcomitant Drug Class/Drug Name: HIV protease inhibitors: Indinavir, nelfinavir; Effect on Concentration of Amprenavir or Concomitant Drug: Fosamprenavir: ↑ Amprenavir Effect on indinavir and nelfinavir is not well established. Fosamprenavir/ ritonavir: Interaction has not been evaluated.; Clinical Comment: Appropriate doses of the combinations with respect to safety and efficacy have not been established.
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 nelfinavir label say about fosamprenavir?
Nelfinavir's label (effective December 11, 2025) 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 (VIRACEPT), AGOURON, effective December 11, 2025 (SPL set e72c2bc6-9462-4a2e-8e1d-b97592376cbd), 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 | Nelfinavir | |
|---|---|---|
| Labeled for | HIV | HIV |
| Boxed warning | No | No |
| 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