Aspirin and Diflunisal Interaction
Drug interaction information between Aspirin and Diflunisal.
Aspirin and Diflunisal have a documented minor interaction in FDA labeling.
FDA drug labeling documents a minor-severity interaction between Aspirin and Diflunisal. 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
Taking these two drugs together can change how they travel in the blood and may slightly lower the amount of diflunisal in your body. This combination also increases the risk of unwanted side effects.
FDA Label Information
Aspirin When diflunisal is administered with aspirin, its protein binding is reduced, although the clearance of free diflunisal is not altered. The clinical significance of this interaction is not known; however, as with other NSAIDs, concomitant administration of diflunisal tablets and aspirin is not generally recommended because of the potential of increased adverse effects. In normal volunteers, a small decrease in diflunisal levels was observed when multiple doses of diflunisal and aspirin were administered concomitantly.
Aspirin Also Interacts With
- Atenolol major
- Fluoxetine major
- Ibandronate major
- Alendronate moderate
- Apixaban moderate
Diflunisal Also Interacts With
- Methotrexate moderate
- Cyclosporine moderate
- Celecoxib moderate
- Indomethacin moderate
- Mefenamic Acid moderate
Frequently Asked Questions
What SPL severity band is on file for Aspirin + Diflunisal?
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?
Aspirin has 47 labeled pairs on file vs Diflunisal's 17. In the minor band specifically: Aspirin has 32 (also Carisoprodol, Celecoxib, Colestipol, Edoxaban); Diflunisal has 6 (also Hydrochlorothiazide, Furosemide, Acetaminophen, Lithium).
What mechanism field is on file for Aspirin and Diflunisal?
Taking these two drugs together can change how they travel in the blood and may slightly lower the amount of diflunisal in your body. This combination also increases the risk of unwanted side effects.
Aspirin carries more major-labeled pairs than Diflunisal
SPL source-record counts only. This page's band is minor · classes on file: Aspirin (Antiplatelet / NSAID); Diflunisal (Nonsteroidal Anti-Inflammatory Drug (NSAID)).
Aspirin has 3 major-labeled pairs vs Diflunisal's 0. This page itself is in the minor band, not the major band.
3 major · 12 moderate · 32 minor · 47 total
- Other minor peers for Aspirin
- Carisoprodol
- Celecoxib
- Colestipol
- Edoxaban
0 major · 11 moderate · 6 minor · 17 total
- Other minor peers for Diflunisal
- Hydrochlorothiazide
- Furosemide
- Acetaminophen
- Lithium
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.