What the FDA labels say about taking them together
Diflunisal and indomethacin
Diflunisal's FDA label of August 4, 2026 names indomethacin in its drug interactions section, and indomethacin's label names diflunisal too. The indomethacin label: “… increase in efficacy [ see Warnings and Precautions () ]. Combined use with diflunisal may be particularly hazardous because diflunisal causes significantly higher plasma levels of indomethacin [ see Clinical …”
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 indomethacin FDA label on DailyMed (effective December 19, 2025, Glenmark Pharmaceuticals Inc., USA).
What does the diflunisal label say about indomethacin?
Diflunisal label, drug interactionsNSAIDs The administration of diflunisal to normal volunteers receiving indomethacin decreased the renal clearance and significantly increased the plasma levels of indomethacin.
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 indomethacin label say about diflunisal?
Indomethacin label, drug interactionsNSAIDs and Salicylates Clinical Impact: Concomitant use of indomethacin with other NSAIDs or salicylates (…) increases the risk of GI toxicity, with little or no increase in efficacy [ see Warnings and Precautions () ]. Combined use with diflunisal may be particularly hazardous because diflunisal causes significantly higher plasma levels of indomethacin [ see Clinical … Intervention: The concomitant use of indomethacin with other NSAIDs or salicylates, especially diflunisal, is not recommended.
Indomethacin label (Chartwell RX, LLC, March 26, 2025), drug interactionsDiflunisal In normal volunteers receiving indomethacin, the administration of diflunisal decreased the renal clearance and significantly increased the plasma levels of indomethacin.
Source: FDA drug label (Indomethacin, NDA018829), Chartwell RX, LLC, effective March 26, 2025 (SPL set 9607920c-4d25-40b9-957e-87e9ca5574e8), via openFDA
Source: FDA drug label (Indomethacin), Glenmark Pharmaceuticals Inc., USA, effective December 19, 2025 (SPL set f7ed39e2-5431-4e47-935c-c7441d058f94), 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 | Indomethacin | |
|---|---|---|
| Labeled for | Pain, Osteoarthritis, Rheumatoid arthritis | Rheumatoid arthritis, Osteoarthritis |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $1.06 per tablet 500 mg tablet | $0.210 per capsule 75 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