Azithromycin and Warfarin Interaction
Drug interaction information between Azithromycin and Warfarin.
Azithromycin and Warfarin have a documented minor interaction in FDA labeling.
FDA drug labeling documents a minor-severity interaction between Azithromycin 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
Azithromycin may increase the effects of warfarin, which can make your blood take longer to clot.
FDA Label Information
( 7.1 ) • Warfarin: Use with azithromycin may increase coagulation times; monitor prothrombin time. [see Adverse Reactions (6) ] 7.2 Warfarin Spontaneous postmarketing reports suggest that concomitant administration of azithromycin may potentiate the effects of oral anticoagulants such as warfarin, although the prothrombin time was not affected in the dedicated drug interaction study with azithromycin and warfarin.
Azithromycin Also Interacts With
- Theophylline major
- Digoxin minor
- Colchicine minor
- Phenytoin minor
- Desloratadine 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 Azithromycin + Warfarin?
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?
Warfarin has 163 labeled pairs on file vs Azithromycin's 9. In the minor band specifically: Azithromycin has 8 (also Digoxin, Colchicine, Phenytoin, Desloratadine); Warfarin has 133 (also Atorvastatin, Amlodipine, Omeprazole, Famotidine).
What mechanism field is on file for Azithromycin and Warfarin?
Azithromycin may increase the effects of warfarin, which can make your blood take longer to clot.
Warfarin carries more major-labeled pairs than Azithromycin
SPL source-record counts only. This page's band is minor · classes on file: Azithromycin (Macrolide Antibiotic); Warfarin (Vitamin K Antagonist (Anticoagulant)).
Warfarin has 2 major-labeled pairs vs Azithromycin's 1. This page itself is in the minor band, not the major band.
1 major · 0 moderate · 8 minor · 9 total
- Other minor peers for Azithromycin
- Digoxin
- Colchicine
- Phenytoin
- Desloratadine
2 major · 28 moderate · 133 minor · 163 total
- Other minor peers for Warfarin
- Atorvastatin
- Amlodipine
- Omeprazole
- Famotidine
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.