Warfarin and Famotidine Interaction
Drug interaction information between Warfarin and Famotidine.
Warfarin and Famotidine have a documented minor interaction in FDA labeling.
FDA drug labeling documents a minor-severity interaction between Warfarin and Famotidine. 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
Famotidine slows down the liver enzymes that break down warfarin. This can cause warfarin to build up in your blood, making it more likely for you to bleed.
Warfarin Also Interacts With
- Fluoxetine major
- Tamoxifen major
- Ibuprofen moderate
- Aspirin moderate
- Diclofenac moderate
Famotidine Also Interacts With
- Theophylline major
- Tizanidine moderate
- Ketoconazole minor
- Ledipasvir/Sofosbuvir minor
- Itraconazole minor
Frequently Asked Questions
What SPL severity band is on file for Warfarin + Famotidine?
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 Famotidine's 11. In the minor band specifically: Warfarin has 133 (also Atorvastatin, Amlodipine, Omeprazole, Alprazolam); Famotidine has 9 (also Ketoconazole, Ledipasvir/Sofosbuvir, Itraconazole, Aripiprazole).
What mechanism field is on file for Warfarin and Famotidine?
Famotidine slows down the liver enzymes that break down warfarin. This can cause warfarin to build up in your blood, making it more likely for you to bleed.
Warfarin carries more major-labeled pairs than Famotidine
SPL source-record counts only. This page's band is minor · classes on file: Warfarin (Vitamin K Antagonist (Anticoagulant)); Famotidine (H2 Receptor Antagonist).
Warfarin has 2 major-labeled pairs vs Famotidine's 1. This page itself is in the minor band, not the major band.
2 major · 28 moderate · 133 minor · 163 total
- Other minor peers for Warfarin
- Atorvastatin
- Amlodipine
- Omeprazole
- Alprazolam
1 major · 1 moderate · 9 minor · 11 total
- Other minor peers for Famotidine
- Ketoconazole
- Ledipasvir/Sofosbuvir
- Itraconazole
- Aripiprazole
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.