Colesevelam and Warfarin Interaction
Drug interaction information between Colesevelam and Warfarin.
Colesevelam and Warfarin have a documented minor interaction in FDA labeling.
FDA drug labeling documents a minor-severity interaction between Colesevelam 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
Colesevelam can lower the amount of warfarin that gets into your blood by binding to the medicine in your stomach. This prevents the warfarin from being absorbed properly into your system.
FDA Label Information
7 DRUG INTERACTIONS Concomitant use with colesevelam hydrochloride may decrease the exposure of the following drugs: Drugs with a narrow therapeutic index (e.g., cyclosporine), phenytoin, thyroid hormone replacement therapy, warfarin, oral contraceptives containing ethinyl estradiol and norethindrone, olmesartan medoxomil, and sulfonylureas (glimepiride, glipizide, glyburide). For patients on warfarin, monitor International Normalized Ratio (INR) frequently during initiation then periodically ( 7.1 ). Warfarin Clinical Impact: There have been postmarketing reports of reduced INR in...
Colesevelam Also Interacts With
- Olmesartan moderate
- Metformin minor
- Norethindrone minor
- Cyclosporine minor
- Glyburide 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 Colesevelam + 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 Colesevelam's 15. In the minor band specifically: Colesevelam has 14 (also Metformin, Norethindrone, Cyclosporine, Glyburide); Warfarin has 133 (also Atorvastatin, Amlodipine, Omeprazole, Famotidine).
What mechanism field is on file for Colesevelam and Warfarin?
Colesevelam can lower the amount of warfarin that gets into your blood by binding to the medicine in your stomach. This prevents the warfarin from being absorbed properly into your system.
Warfarin carries more major-labeled pairs than Colesevelam
SPL source-record counts only. This page's band is minor · classes on file: Colesevelam (Bile Acid Sequestrant (Diabetes)); Warfarin (Vitamin K Antagonist (Anticoagulant)).
Warfarin has 2 major-labeled pairs vs Colesevelam's 0. This page itself is in the minor band, not the major band.
0 major · 1 moderate · 14 minor · 15 total
- Other minor peers for Colesevelam
- Metformin
- Norethindrone
- Cyclosporine
- Glyburide
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.