Leflunomide and Furosemide Interaction

Drug interaction information between Leflunomide and Furosemide.

Leflunomide and Furosemide have a documented minor interaction in FDA labeling.

FDA drug labeling documents a minor-severity interaction between Leflunomide and Furosemide. This page displays the available source-record category and label text. The category is not an individual risk estimate or medication-combination direction.

Drug A

Leflunomide

Disease-Modifying Antirheumatic Drug (DMARD)

Drug B

Furosemide

Loop Diuretic

How They Interact

Leflunomide interferes with a protein that helps the body remove furosemide, which can cause the levels of furosemide in your blood to rise.

FDA Label Information

In patients taking leflunomide, exposure of drugs which are OAT3 substrates (e.g., cefaclor, cimetidine, ciprofloxacin, penicillin G, ketoprofen, furosemide, methotrexate, zidovudine) may be increased.

Frequently Asked Questions

What SPL severity band is on file for Leflunomide + Furosemide?

Compiled FDA labeling labels this pair minor. That is a source-record field, not an individual medication-combination decision.

Which drug in this pair has the larger labeled-interaction portfolio?

Furosemide has 36 labeled pairs on file vs Leflunomide's 20. In the minor band specifically: Leflunomide has 20 (also Atorvastatin, Rosuvastatin, Simvastatin, Duloxetine); Furosemide has 29 (also Methotrexate, Norepinephrine, Ethacrynic Acid, Indomethacin).

What mechanism field is on file for Leflunomide and Furosemide?

Leflunomide interferes with a protein that helps the body remove furosemide, which can cause the levels of furosemide in your blood to rise.

Furosemide carries more major-labeled pairs than Leflunomide

SPL source-record counts only. This page's band is minor · classes on file: Leflunomide (Disease-Modifying Antirheumatic Drug (DMARD)); Furosemide (Loop Diuretic).

Furosemide has 3 major-labeled pairs vs Leflunomide's 0. This page itself is in the minor band, not the major band.

Leflunomide

0 major · 0 moderate · 20 minor · 20 total

Furosemide

3 major · 4 moderate · 29 minor · 36 total

Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. This registry does not provide individual medication-combination directions.