What the FDA labels say about taking them together
Fosamprenavir and vinblastine
Fosamprenavir's FDA label of September 15, 2023 names vinblastine in its drug interactions section; the vinblastine label PlainMeds reads does not name fosamprenavir. The fosamprenavir label: “Fosamprenavir or fosamprenavir/ritonavir may increase plasma concentrations of antineoplastics metabolized by CYP3A, potentially increasing the risk of adverse events typically associated with these medications. …”
Check it at the source: the fosamprenavir FDA label on DailyMed (effective September 15, 2023, Mylan Pharmaceuticals Inc.); the vinblastine FDA label on DailyMed (effective April 15, 2025, Fresenius Kabi USA, LLC).
What does the fosamprenavir label say about vinblastine?
Fosamprenavir label, drug interactionsConcomitant Drug Class/Drug Name: Antineoplastics: Dasatinib, nilotinib, ibrutinib, vinblastine, everolimus; Effect on Concentration of Amprenavir or Concomitant Drug: ↑ Antineoplastics; Clinical Comment: Fosamprenavir or fosamprenavir/ritonavir may increase plasma concentrations of antineoplastics metabolized by CYP3A, potentially increasing the risk of adverse events typically associated with these medications. In case of coadministration, please refer to relevant prescribing information for these medications.
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 vinblastine label say about fosamprenavir?
Vinblastine's label (effective April 15, 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 (Vinblastine Sulfate), Fresenius Kabi USA, LLC, effective April 15, 2025 (SPL set f073b58e-56d6-4c8d-a2ce-b37719402d77), 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 | Vinblastine | |
|---|---|---|
| Labeled for | HIV | Leukemia, lymphoma and myeloma |
| 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