What the FDA labels say about taking them together
Furosemide and indomethacin
Furosemide's FDA label of September 30, 2025 names indomethacin in its drug interactions section, and indomethacin's label names furosemide too. The indomethacin 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 indomethacin FDA label on DailyMed (effective December 19, 2025, Glenmark Pharmaceuticals Inc., USA).
What does the furosemide label say about indomethacin?
Furosemide label, drug interactionsLiterature reports indicate that coadministration of indomethacin may reduce the natriuretic and antihypertensive effects of LASIX (furosemide) in some patients by inhibiting prostaglandin synthesis.
Source: FDA drug label (Furosemide, NDA018267), Hikma Pharmaceuticals USA Inc., effective March 10, 2025 (SPL set ddfc41a9-37d4-49c1-bbf3-969a98cd649c), via openFDA
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 indomethacin label say about furosemide?
Indomethacin label, 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: Indomethacin and triamterene should not be administered together. During concomitant use of indomethacin capsules with diuretics, observe patients for signs of worsening renal function, in addition to assuring diuretic efficacy including antihypertensive effects. …
Indomethacin label (Chartwell RX, LLC, March 26, 2025), drug interactionsIndomethacin reduces basal plasma renin activity (PRA), as well as those elevations of PRA induced by furosemide administration, or salt or volume depletion.
Indomethacin label (Fresenius Kabi USA, LLC, January 19, 2026), drug interactionsTherapy with indomethacin may blunt the natriuretic effect of furosemide.
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, NDA022536), Fresenius Kabi USA, LLC, effective January 19, 2026 (SPL set ec482425-358c-4500-8f5d-79c1379c1fa8), 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
| Furosemide | Indomethacin | |
|---|---|---|
| Labeled for | Heart failure, High blood pressure, Edema (fluid retention) | Rheumatoid arthritis, Osteoarthritis |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $0.490 per mL 20 mg/2 mL vial | $0.210 per capsule 75 mg capsule |
| 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