Cholestyramine and Ezetimibe: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Cholestyramine
Ezetimibe
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
Reduced ezetimibe exposure and reduced efficacy of ezetimibe
Interaction Deep Dive
Concomitant use of ezetimibe and a bile acid sequestrant, decreases ezetimibe exposure, which may result in a reduced efficacy of ezetimibe. In a pharmacokinetic study, concomitant use of ezetimibe and cholestyramine reduced the mean AUC of total ezetimibe by approximately 55%. Administer ezetimibe at least 2 hours before or at least 4 hours after bile acid sequestrants312.
Why it happens (mechanism)
Reduced ezetimibe absorption
Literature reports
1 report — tap to read
a) In a pharmacokinetic study of healthy hypercholesterolemic adults (n=40), total ezetimibe (ezetimibe plus ezetimibe-glucuronide (pharmacologically active metabolite)) and ezetimibe plasma mean area under the concentration-time curve declined by approximately 55% and 80%, respectively when given concurrently with cholestyramine 4 grams twice daily 12.
Common questions
Can I take Cholestyramine and Ezetimibe together?
Reduced ezetimibe exposure and reduced efficacy of ezetimibe Always confirm with your pharmacist or prescriber before making any change.
How serious is the Cholestyramine and Ezetimibe interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
Questions for your pharmacist
- Does my dose of Cholestyramine or Ezetimibe need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (3)
- Product Information: ZETIA(R) oral tablets, ezetimibe oral tablets. Organon LLC (per FDA), Jersey City, NJ, 2023. DailyMed
- Product Information: VYTORIN(R) oral tablets, ezetimibe simvastatin oral tablets. Organon LLC (per FDA), Jersey City, NJ, 2024. DailyMed
- Product Information: Ezetimibe oral tablets, ezetimibe oral tablets. Aurobindo Pharma USA Inc (per DailyMed), East Windsor, NJ, 2020. DailyMed
Keep reading about Cholestyramine
Keep reading about Ezetimibe
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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