What the FDA labels say about taking them together
Fosamprenavir and nizatidine
Fosamprenavir's FDA label of September 15, 2023 names nizatidine in its drug interactions section; the nizatidine label PlainMeds reads does not name fosamprenavir. The fosamprenavir label: “Use with caution. Fosamprenavir may be less effective due to decreased amprenavir plasma concentrations.”
Check it at the source: the fosamprenavir FDA label on DailyMed (effective September 15, 2023, Mylan Pharmaceuticals Inc.); the nizatidine FDA label on DailyMed (effective January 2, 2025, Epic Pharma, LLC).
What does the fosamprenavir label say about nizatidine?
Fosamprenavir label, drug interactionsConcomitant Drug Class/Drug Name: Histamine H 2 -receptor antagonists: Cimetidine, famotidine, nizatidine, ranitidine; Effect on Concentration of Amprenavir or Concomitant Drug: Fosamprenavir: ↓ Amprenavir Fosamprenavir/ ritonavir: Interaction not evaluated; Clinical Comment: Use with caution. Fosamprenavir may be less effective due to decreased amprenavir plasma concentrations.
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 nizatidine label say about fosamprenavir?
Nizatidine's label (effective January 2, 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 (Nizatidine), Epic Pharma, LLC, effective January 2, 2025 (SPL set e9957997-8b85-48a0-9bb3-b878cb223236), 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 | Nizatidine | |
|---|---|---|
| Labeled for | HIV | Acid reflux and ulcers |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | n/a | $0.804 per capsule 150 mg capsule |
| 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