What the FDA labels say about taking them together
Furosemide and leflunomide
Leflunomide's FDA label of June 4, 2025 names furosemide in its drug interactions section; the furosemide labels PlainMeds reads (4) do not name leflunomide. The leflunomide label: “In patients taking ARAVA, exposure of drugs which are OAT3 substrates may be increased.”
Check it at the source: the furosemide FDA label on DailyMed (effective September 30, 2025, Validus Pharmaceuticals LLC); the leflunomide FDA label on DailyMed (effective June 4, 2025, sanofi-aventis U.S. LLC).
What does the furosemide label say about leflunomide?
Furosemide's label (effective September 30, 2025) and its 3 other brand-application labels do not name leflunomide in these sections. A label lists what its studies and reports found; it is not a complete list.
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 leflunomide label say about furosemide?
Leflunomide label, drug interactionsIn patients taking ARAVA, exposure of drugs which are OAT3 substrates (e.g., cefaclor, cimetidine, ciprofloxacin, penicillin G, ketoprofen, furosemide, methotrexate, zidovudine) may be increased.
Source: FDA drug label (Arava), sanofi-aventis U.S. LLC, effective June 4, 2025 (SPL set 320f63f2-fac3-4aee-aff8-85724e00ef52), 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 | Leflunomide | |
|---|---|---|
| Labeled for | Heart failure, High blood pressure, Edema (fluid retention) | Rheumatoid arthritis |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $0.490 per mL 20 mg/2 mL vial | $0.324 per tablet 10 mg tablet |
| Shortage now | In shortage | 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