What the FDA labels say about taking them together
Diclofenac and furosemide
Diclofenac's FDA label of February 11, 2025 names furosemide in its drug interactions (prescription label) section; furosemide's label does not name diclofenac itself but warns about its class (NSAIDs (nonsteroidal anti-inflammatory drugs)). The diclofenac label: “Clinical studies, as well as post-marketing observations, showed that NSAIDs reduced the natriuretic effect of loop diuretics (e.g., furosemide) and thiazide diuretics in some patients. …”
Check it at the source: the diclofenac FDA label on DailyMed (effective February 11, 2025, Haleon US Holdings LLC); the furosemide FDA label on DailyMed (effective September 30, 2025, Validus Pharmaceuticals LLC).
What does the diclofenac label say about furosemide?
Diclofenac label, drug interactions (prescription label)Clinical studies, as well as post-marketing observations, have shown that NSAIDs can reduce the natriuretic effect of furosemide and thiazides in some patients.
Licart label (IBSA Pharma Inc., April 2, 2026), drug interactionsDiuretics Clinical Impact: Clinical studies, as well as post-marketing observations, showed that NSAIDs reduced the natriuretic effect of loop diuretics (e.g., furosemide) and thiazide diuretics in some patients. This effect has been attributed to the NSAID inhibition of renal prostaglandin synthesis. Intervention: During concomitant use of LICART with diuretics, observe patients for signs of worsening renal function, in addition to assuring diuretic efficacy including antihypertensive effects [see ].
Source: FDA drug label (Licart, NDA206976), IBSA Pharma Inc., effective April 2, 2026 (SPL set 851c8b39-6056-4bbc-812e-b9b13977c1ac), via openFDA
Source: FDA drug label (Voltaren Arthritis Pain), Haleon US Holdings LLC, effective February 11, 2025 (SPL set 30a94282-0892-442a-aa10-6525cbd4fe88), via openFDA; the full label on DailyMed
What does the furosemide label say about diclofenac?
Furosemide's label does not name diclofenac itself; it warns about its class (NSAIDs (nonsteroidal anti-inflammatory drugs)):
Furosemide label, drug interactionsThere are case reports of patients who developed increased BUN, serum creatinine and serum potassium levels, and weight gain when furosemide was used in conjunction with NSAIDs.
Source: FDA drug label (Lasix), Validus Pharmaceuticals LLC, effective September 30, 2025 (SPL set 2c9b4d8f-0770-482d-a9e6-9c616a440b1a), 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
| Diclofenac | Furosemide | |
|---|---|---|
| Labeled for | Pain, Osteoarthritis, Rheumatoid arthritis, Migraine | Heart failure, High blood pressure, Edema (fluid retention) |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $0.0619 per tablet 75 mg tablet | $0.490 per mL 20 mg/2 mL vial |
| Shortage now | A presentation being discontinued | In shortage |
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