What the FDA labels say about taking them together
Flecainide and fosamprenavir
Fosamprenavir's FDA label of September 15, 2023 names flecainide in its contraindications section; the flecainide label PlainMeds reads does not name fosamprenavir. The fosamprenavir label: “Coadministration is contraindicated due to potential for serious and/or life-threatening reactions such as cardiac arrhythmias if fosamprenavir is co-prescribed with ritonavir.”
Check it at the source: the flecainide FDA label on DailyMed (effective June 11, 2026, Amneal Pharmaceuticals of New York LLC); the fosamprenavir FDA label on DailyMed (effective September 15, 2023, Mylan Pharmaceuticals Inc.).
What does the flecainide label say about fosamprenavir?
Flecainide's label (effective June 11, 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 (Flecainide Acetate), Amneal Pharmaceuticals of New York LLC, effective June 11, 2026 (SPL set ee9595d5-08a1-4529-9215-ddc3c7f929c4), via openFDA; the full label on DailyMed
What does the fosamprenavir label say about flecainide?
Fosamprenavir label, contraindicationsAlfuzosin o Antiarrhythmics: Flecainide (with ritonavir ), propafenone (with ritonavir ) o Antimycobacterial:
Fosamprenavir label, drug interactionsConcomitant Drug Class/Drug Name: Antiarrhythmics: Flecainide, propafenone; Effect on Concentration of Amprenavir or Concomitant Drug: ↑ Antiarrhythmics; Clinical Comment: Coadministration is contraindicated due to potential for serious and/or life-threatening reactions such as cardiac arrhythmias if fosamprenavir is co-prescribed with ritonavir [see ].
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
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
| Flecainide | Fosamprenavir | |
|---|---|---|
| Labeled for | n/a | HIV |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.171 per tablet 100 mg tablet | 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