What the FDA labels say about taking them together
Diflunisal and naproxen
Diflunisal's FDA label of August 4, 2026 names naproxen in its drug interactions section, and naproxen's label names diflunisal too. The naproxen label: “Concomitant use of naproxen with other NSAIDs or salicylates increases the risk of GI toxicity, with little or no increase in efficacy.”
Check it at the source: the diflunisal FDA label on DailyMed (effective August 4, 2026, Heritage Pharmaceuticals Inc. d/b/a Avet Pharmaceuticals Inc.); the naproxen FDA label on DailyMed (effective March 12, 2026, Bayer HealthCare LLC.).
What does the diflunisal label say about naproxen?
Diflunisal label, drug interactionsNaproxen The concomitant administration of diflunisal and naproxen in normal volunteers had no effect on the plasma levels of naproxen, but significantly decreased the urinary excretion of naproxen and its glucuronide metabolite.
Source: FDA drug label (diflunisal), Heritage Pharmaceuticals Inc. d/b/a Avet Pharmaceuticals Inc., effective August 4, 2026 (SPL set 666f89b4-fd81-420a-a390-eb1cd4014f61), via openFDA; the full label on DailyMed
What does the naproxen label say about diflunisal?
Naproxen label, drug interactions (prescription label)NSAIDs and Salicylates Clinical Impact: Concomitant use of naproxen with other NSAIDs or salicylates (…) increases the risk of GI toxicity, with little or no increase in efficacy [ see Warnings and Precautions () ]. Intervention: The concomitant use of naproxen with other NSAIDs or salicylates is not recommended.
Source: FDA drug label (Naproxen, NDA020067), Zameer Pharmaceuticals LLC, effective August 23, 2025 (SPL set d2e5553a-7c90-407c-9f07-3be65560c23a), via openFDA
Source: FDA drug label (Aleve Caplets), Bayer HealthCare LLC., effective March 12, 2026 (SPL set 02941928-128a-2c88-e063-6294a90ac6ba), 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
| Diflunisal | Naproxen | |
|---|---|---|
| Labeled for | Pain, Osteoarthritis, Rheumatoid arthritis | Fever, Rheumatoid arthritis, Osteoarthritis, Gout, Pain, Cough and cold |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $1.06 per tablet 500 mg tablet | $0.0565 per tablet 500 mg tablet |
| 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