Mefenamic Acid and Furosemide Interaction

Drug interaction information between Mefenamic Acid and Furosemide.

Mefenamic Acid and Furosemide have a documented minor interaction in FDA labeling.

FDA drug labeling documents a minor-severity interaction between Mefenamic Acid 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

Mefenamic Acid

Nonsteroidal Anti-Inflammatory Drug (NSAID)

Drug B

Furosemide

Loop Diuretic

How They Interact

Mefenamic acid can block the effects of furosemide, making it harder for your body to remove extra salt and water through your urine.

FDA Label Information

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.

Mefenamic Acid Also Interacts With

View all Mefenamic Acid interactions →

Frequently Asked Questions

What SPL severity band is on file for Mefenamic Acid + 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 Mefenamic Acid's 15. In the minor band specifically: Mefenamic Acid has 12 (also Meloxicam, Aspirin, Propranolol, Diclofenac); Furosemide has 29 (also Methotrexate, Norepinephrine, Ethacrynic Acid, Indomethacin).

What mechanism field is on file for Mefenamic Acid and Furosemide?

Mefenamic acid can block the effects of furosemide, making it harder for your body to remove extra salt and water through your urine.

Furosemide carries more major-labeled pairs than Mefenamic Acid

SPL source-record counts only. This page's band is minor · classes on file: Mefenamic Acid (Nonsteroidal Anti-Inflammatory Drug (NSAID)); Furosemide (Loop Diuretic).

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

Mefenamic Acid

0 major · 3 moderate · 12 minor · 15 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.