What the FDA labels say about taking them together
Diltiazem and fosamprenavir
Fosamprenavir's FDA label of September 15, 2023 names diltiazem in its drug interactions section; the diltiazem labels PlainMeds reads (4) do not name fosamprenavir. The fosamprenavir label: “Use with caution. Clinical monitoring of patients is recommended.”
Check it at the source: the diltiazem FDA label on DailyMed (effective August 7, 2026, Bausch Health US, LLC); the fosamprenavir FDA label on DailyMed (effective September 15, 2023, Mylan Pharmaceuticals Inc.).
What does the diltiazem label say about fosamprenavir?
Diltiazem's label (effective August 7, 2026) and its 3 other brand-application labels do 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 (TIAZAC EXTENDED RELEASE), Bausch Health US, LLC, effective August 7, 2026 (SPL set c567fe7e-887e-4291-a0d1-2dd3f25cbf25), via openFDA; the full label on DailyMed
What does the fosamprenavir label say about diltiazem?
Fosamprenavir label, drug interactionsConcomitant Drug Class/Drug Name: Calcium channel blockers: Diltiazem, felodipine, nifedipine, nicardipine, nimodipine, verapamil, amlodipine, nisoldipine, isradipine; Effect on Concentration of Amprenavir or Concomitant Drug: ↑ Calcium channel blockers; Clinical Comment: Use with caution. Clinical monitoring of patients is 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
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
| Diltiazem | Fosamprenavir | |
|---|---|---|
| Labeled for | High blood pressure, Angina, Atrial fibrillation | HIV |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.144 per capsule 24h ER(cd) 120 mg capsule | n/a |
| Shortage now | A presentation being discontinued | 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