What the FDA labels say about taking them together
Furosemide and naproxen
Naproxen's FDA label of March 12, 2026 names furosemide in its drug interactions (prescription label) section; furosemide's label does not name naproxen itself but warns about its class (NSAIDs (nonsteroidal anti-inflammatory drugs)). The naproxen 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 furosemide FDA label on DailyMed (effective September 30, 2025, Validus Pharmaceuticals LLC); the naproxen FDA label on DailyMed (effective March 12, 2026, Bayer HealthCare LLC.).
What does the furosemide label say about naproxen?
Furosemide's label does not name naproxen 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
What does the naproxen label say about furosemide?
Naproxen label, drug interactions (prescription label)Diuretics 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 naproxen tablets or naproxen sodium tablets with diuretics, observe patients for signs of worsening renal function, in addition to assuring diuretic efficacy including antihypertensive effects [ see Warnings and Precautions () ].
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
| Furosemide | Naproxen | |
|---|---|---|
| Labeled for | Heart failure, High blood pressure, Edema (fluid retention) | Fever, Rheumatoid arthritis, Osteoarthritis, Gout, Pain, Cough and cold |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $0.490 per mL 20 mg/2 mL vial | $0.0565 per tablet 500 mg tablet |
| Shortage now | In shortage | 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