What the FDA labels say about taking them together
Diflunisal and hydrochlorothiazide
Diflunisal's FDA label of August 4, 2026 names hydrochlorothiazide in its drug interactions section; hydrochlorothiazide's label does not name diflunisal itself but warns about its class (NSAIDs (nonsteroidal anti-inflammatory drugs)). The diflunisal label: “In normal volunteers, concomitant administration of diflunisal and hydrochlorothiazide resulted in significantly increased plasma levels of hydrochlorothiazide.”
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 hydrochlorothiazide FDA label on DailyMed (effective June 12, 2026, Leading Pharma, LLC).
What does the diflunisal label say about hydrochlorothiazide?
Diflunisal label, drug interactionsIn normal volunteers, concomitant administration of diflunisal and hydrochlorothiazide resulted in significantly increased plasma levels of hydrochlorothiazide.
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 hydrochlorothiazide label say about diflunisal?
Hydrochlorothiazide's label does not name diflunisal itself; it warns about its class (NSAIDs (nonsteroidal anti-inflammatory drugs)):
Hydrochlorothiazide label, drug interactionsNon-steroidal anti-inflammatory drugs - In some patients, the administration of a non-steroidal anti-inflammatory agent can reduce the diuretic, natriuretic, and antihypertensive effects of loop, potassium-sparing and thiazide diuretics.
Hydrochlorothiazide label, drug interactionsNon-steroidal anti-inflammatory drugs - In some patients, the administration of a non-steroidal anti-inflammatory agent can reduce the diuretic, natriuretic, and antihypertensive effects of loop, potassium-sparing and thiazide diuretics. When hydrochlorothiazide and non-steroidal anti-inflammatory agents are used concomitantly, the patients should be observed closely to determine if the desired effect of the diuretic is obtained.
Source: FDA drug label (HYDROCHLOROTHIAZIDE), Leading Pharma, LLC, effective June 12, 2026 (SPL set 8c868894-667e-4a51-906a-838d63e420ba), 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 | Hydrochlorothiazide | |
|---|---|---|
| Labeled for | Pain, Osteoarthritis, Rheumatoid arthritis | Heart failure, High blood pressure, Edema (fluid retention) |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $1.06 per tablet 500 mg tablet | $0.0115 per tablet 25 mg tablet |
| Shortage now | No current entry | A presentation being discontinued |
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