Drug interactions
Cholestyramine + Warfarin
Severity: Moderate
Cholestyramine and Warfarin: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Cholestyramine binds warfarin in the gut and also interrupts its enterohepatic recirculation, reducing its absorption and anticoagulant effect. This may lower the INR and increase the risk of thrombosis.
What this interaction means in plain words
Cholestyramine and Warfarin can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Cholestyramine belongs to Cardiovascular; Warfarin belongs to Cardiovascular.
Why it happens
Binding of warfarin by the bile acid sequestrant resin in the gastrointestinal tract reduces absorption and enterohepatic recycling.
What to do
Give warfarin at least 3 to 4 hours apart from cholestyramine, and monitor INR closely when starting, stopping or changing the cholestyramine dose. Adjust the warfarin dose as needed.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Cholestyramine and Warfarin, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
Other interactions of Warfarin
- Defibrotide + Warfarin Contraindicated
- Ketorolac + Warfarin Contraindicated
- Abciximab + Warfarin Major
- Acetylsalicylic acid + Warfarin Major
- Adagrasib + Warfarin Major
- Amiodarone + Warfarin Major
Other interactions of Cholestyramine
Frequently asked questions
Can I take Cholestyramine with Warfarin?
MediHelp rates the interaction as moderate. Cholestyramine and Warfarin can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Cholestyramine binds warfarin in the gut and also interrupts its enterohepatic recirculation, reducing its absorption and anticoagulant effect. This may lower the INR and increase the risk of thrombosis.
How serious is the interaction between Cholestyramine and Warfarin?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Give warfarin at least 3 to 4 hours apart from cholestyramine, and monitor INR closely when starting, stopping or changing the cholestyramine dose. Adjust the warfarin dose as needed.
What other medicines interact with Warfarin?
MediHelp also lists interactions of Warfarin with, for example, Defibrotide, Ketorolac, Abciximab. The full list is on the Warfarin page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
