Mefenamic Acid and Warfarin Interaction
Drug interaction information between Mefenamic Acid and Warfarin.
Mefenamic Acid and Warfarin have a documented moderate interaction in FDA labeling.
FDA drug labeling documents a moderate-severity interaction between Mefenamic Acid and Warfarin. 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
Mefenamic acid can increase the risk of bleeding when used with warfarin. These drugs work together to slow down blood clotting more than usual.
Mefenamic Acid Also Interacts With
- Methotrexate moderate
- Diflunisal moderate
- Meloxicam minor
- Furosemide minor
- Aspirin minor
Warfarin Also Interacts With
- Fluoxetine major
- Tamoxifen major
- Ibuprofen moderate
- Aspirin moderate
- Diclofenac moderate
Frequently Asked Questions
What SPL severity band is on file for Mefenamic Acid + Warfarin?
Compiled FDA labeling labels this pair moderate. That is a source-record field, not an individual medication-combination decision.
Which drug in this pair has the larger labeled-interaction portfolio?
Warfarin has 163 labeled pairs on file vs Mefenamic Acid's 15. In the moderate band specifically: Mefenamic Acid has 3 (also Methotrexate, Diflunisal); Warfarin has 28 (also Ibuprofen, Aspirin, Diclofenac, Desvenlafaxine).
What mechanism field is on file for Mefenamic Acid and Warfarin?
Mefenamic acid can increase the risk of bleeding when used with warfarin. These drugs work together to slow down blood clotting more than usual.
Warfarin carries more major-labeled pairs than Mefenamic Acid
SPL source-record counts only. This page's band is moderate · classes on file: Mefenamic Acid (Nonsteroidal Anti-Inflammatory Drug (NSAID)); Warfarin (Vitamin K Antagonist (Anticoagulant)).
Warfarin has 2 major-labeled pairs vs Mefenamic Acid's 0. This page itself is in the moderate band, not the major band.
0 major · 3 moderate · 12 minor · 15 total
- Other moderate peers for Mefenamic Acid
- Methotrexate
- Diflunisal
2 major · 28 moderate · 133 minor · 163 total
- Other moderate peers for Warfarin
- Ibuprofen
- Aspirin
- Diclofenac
- Desvenlafaxine
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.