Cholestyramine and Warfarin Interaction

Drug interaction information between Cholestyramine and Warfarin.

Cholestyramine and Warfarin have a documented minor interaction in FDA labeling.

FDA drug labeling documents a minor-severity interaction between Cholestyramine 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.

Drug A

Cholestyramine

Bile Acid Sequestrant

Drug B

Warfarin

Vitamin K Antagonist (Anticoagulant)

How They Interact

Cholestyramine can trap warfarin in your digestive system, which stops your body from absorbing it. This can make the blood thinner less effective.

FDA Label Information

Drug Interactions Cholestyramine resin may delay or reduce the absorption of concomitant oral medication such as phenylbutazone, warfarin, thiazide diuretics (acidic) or propranolol (basic), as well as tetracycline, penicillin G, phenobarbital, thyroid and thyroxine preparations, estrogens and progestins and digitalis.

Cholestyramine Also Interacts With

View all Cholestyramine interactions →

Warfarin Also Interacts With

View all Warfarin interactions →

Frequently Asked Questions

What SPL severity band is on file for Cholestyramine + 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 Cholestyramine's 34. In the minor band specifically: Cholestyramine has 31 (also Propranolol, Tetracycline, Phenobarbital, Amiodarone); Warfarin has 133 (also Atorvastatin, Amlodipine, Omeprazole, Famotidine).

What mechanism field is on file for Cholestyramine and Warfarin?

Cholestyramine can trap warfarin in your digestive system, which stops your body from absorbing it. This can make the blood thinner less effective.

Warfarin carries more major-labeled pairs than Cholestyramine

SPL source-record counts only. This page's band is minor · classes on file: Cholestyramine (Bile Acid Sequestrant); Warfarin (Vitamin K Antagonist (Anticoagulant)).

Warfarin has 2 major-labeled pairs vs Cholestyramine's 0. This page itself is in the minor band, not the major band.

Cholestyramine

0 major · 3 moderate · 31 minor · 34 total

Warfarin

2 major · 28 moderate · 133 minor · 163 total

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.