Cholestyramine and Propranolol Interaction
Drug interaction information between Cholestyramine and Propranolol.
Cholestyramine and Propranolol have a documented minor interaction in FDA labeling.
FDA drug labeling documents a minor-severity interaction between Cholestyramine and Propranolol. Major interactions are generally avoided, moderate ones may need monitoring or a dose adjustment, and minor ones are usually low-risk. This page shows the documented mechanism and guidance. Label-documented interactions are not a complete safety review, so always confirm your own medications with a pharmacist or doctor. Educational information, not medical advice.
How They Interact
Cholestyramine can bind to propranolol in your gut and prevent it from entering your bloodstream. This means you might not get the full effect of the propranolol.
What To Do
Take your other medications at least one hour before or four to six hours after taking cholestyramine.
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
- Naproxen moderate
- Olmesartan moderate
- Raloxifene moderate
- Warfarin minor
- Tetracycline minor
Frequently Asked Questions
Can I take Cholestyramine and Propranolol together?
This is a minor interaction. Take your other medications at least one hour before or four to six hours after taking cholestyramine.
How serious is the interaction between Cholestyramine and Propranolol?
This interaction is classified as "minor" severity by the FDA. Minor interactions are unlikely to cause significant problems but should still be mentioned to your healthcare provider.
Why do Cholestyramine and Propranolol interact?
Cholestyramine can bind to propranolol in your gut and prevent it from entering your bloodstream. This means you might not get the full effect of the propranolol.
Understanding the Cholestyramine and Propranolol Interaction
FDA-approved prescribing information for these two drugs flags their combination as a minor-severity interaction. Cholestyramine belongs to the Bile Acid Sequestrant class and Propranolol belongs to the Non-Selective Beta-Blocker class - two categories that can collide when co-prescribed. The mechanism described in FDA labeling is: Cholestyramine can bind to propranolol in your gut and prevent it from entering your bloodstream. Severity tiers matter: major flags generally advise avoidance, moderate flags often require monitoring or dose adjustment, and minor flags may only call for awareness.
Context around a specific patient determines real-world impact. Cholestyramine has 34 total documented interactions on file in this dataset, and Propranolol has 44. Each additional medication compounds the interaction surface, which is why pharmacists run full-profile checks rather than evaluating one pair at a time. FDA-derived guidance for this pair is: Take your other medications at least one hour before or four to six hours after taking cholestyramine. Timing of doses, renal and hepatic function, age, and other concurrent prescriptions all shape whether a labeled interaction matters clinically.
An interaction flag is not a verdict. A large share of labeled interactions are managed routinely in clinical practice, the fix may be as simple as spacing doses or adding a monitoring test. Others require the prescriber to choose a different medication entirely. This page surfaces FDA-sourced labeling and openFDA data for educational purposes only; it is not medical advice and cannot account for your full clinical picture. Never start, stop, or adjust either Cholestyramine or Propranolol based on a web page, speak with your prescriber or pharmacist before making any change.
Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. Always consult your healthcare provider about drug interactions.
Read our methodology - how this data is sourced, computed, and verified.