Naproxen and Furosemide Interaction
Drug interaction information between Naproxen and Furosemide.
Naproxen and Furosemide have a documented minor interaction in FDA labeling.
FDA drug labeling documents a minor-severity interaction between Naproxen 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.
How They Interact
Naproxen can make 'water pills' like furosemide less effective at removing extra salt and fluid from your body. This happens because the pain reliever interferes with how the kidneys process salt.
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. ( 7 ) Diuretics: NSAIDs can reduce natriuretic effect of furosemide and thiazide diuretics.
Naproxen Also Interacts With
- Methotrexate moderate
- Magnesium Oxide moderate
- Diflunisal moderate
- Sucralfate moderate
- Cholestyramine moderate
Furosemide Also Interacts With
- Dutasteride major
- Dutasteride/Tamsulosin major
- Tamsulosin major
- Cyclosporine moderate
- Lithium moderate
Frequently Asked Questions
What SPL severity band is on file for Naproxen + 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 Naproxen's 23. In the minor band specifically: Naproxen has 18 (also Meloxicam, Aspirin, Propranolol, Diclofenac); Furosemide has 29 (also Methotrexate, Norepinephrine, Ethacrynic Acid, Indomethacin).
What mechanism field is on file for Naproxen and Furosemide?
Naproxen can make 'water pills' like furosemide less effective at removing extra salt and fluid from your body. This happens because the pain reliever interferes with how the kidneys process salt.
Furosemide carries more major-labeled pairs than Naproxen
SPL source-record counts only. This page's band is minor · classes on file: Naproxen (Nonsteroidal Anti-Inflammatory Drug (NSAID)); Furosemide (Loop Diuretic).
Furosemide has 3 major-labeled pairs vs Naproxen's 0. This page itself is in the minor band, not the major band.
0 major · 5 moderate · 18 minor · 23 total
- Other minor peers for Naproxen
- Meloxicam
- Aspirin
- Propranolol
- Diclofenac
3 major · 4 moderate · 29 minor · 36 total
- Other minor peers for Furosemide
- Methotrexate
- Norepinephrine
- Ethacrynic Acid
- Indomethacin
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.
Read our methodology - how this data is sourced, computed, and verified.