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Colesevelam and Olmesartan Interaction

Drug interaction information between Colesevelam and Olmesartan.

Colesevelam and Olmesartan have a documented moderate interaction in FDA labeling.

FDA drug labeling documents a moderate-severity interaction between Colesevelam and Olmesartan. 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.

Drug A

Colesevelam

Bile Acid Sequestrant (Diabetes)

Drug B

Olmesartan

Angiotensin II Receptor Blocker (ARB)

How They Interact

Colesevelam can stick to olmesartan in your stomach, which prevents your body from absorbing the blood pressure medicine correctly.

What To Do

You should take your olmesartan dose at least 4 hours before you take colesevelam.

FDA Label Information

7 DRUG INTERACTIONS Lithium: Risk of lithium toxicity ( 7.2 ) Non-Steroidal Anti-Inflammatory Drugs (NSAIDs): Reduced diuretic, natriuretic and antihypotensive effects; increased risk of renal toxicity ( 7.3 ) Dual inhibition of the renin-angiotensin system: Increased risk of renal impairment, hypotension, and hyperkalemia ( 7.4 ) Colesevelam hydrochloride: Consider administering olmesartan at least 4 hours before colesevelam hydrochloride dose ( 7.5 ) Antidiabetic drugs: Dosage adjustment may be required ( 7.6 ) Cholestyramine and colestipol: Reduced absorption of thiazides ( 7.6 ) 7.1...

Frequently Asked Questions

Can I take Colesevelam and Olmesartan together?

This is a moderate interaction. You should take your olmesartan dose at least 4 hours before you take colesevelam.

How serious is the interaction between Colesevelam and Olmesartan?

This interaction is classified as "moderate" severity by the FDA. Moderate interactions may worsen your condition or change how your medications work.

Why do Colesevelam and Olmesartan interact?

Colesevelam can stick to olmesartan in your stomach, which prevents your body from absorbing the blood pressure medicine correctly.

Understanding the Colesevelam and Olmesartan Interaction

FDA-approved prescribing information for these two drugs flags their combination as a moderate-severity interaction. Colesevelam belongs to the Bile Acid Sequestrant (Diabetes) class and Olmesartan belongs to the Angiotensin II Receptor Blocker (ARB) class - two categories that can collide when co-prescribed. The mechanism described in FDA labeling is: Colesevelam can stick to olmesartan in your stomach, which prevents your body from absorbing the blood pressure medicine correctly. 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. Colesevelam has 15 total documented interactions on file in this dataset, and Olmesartan has 7. 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: You should take your olmesartan dose at least 4 hours before you take colesevelam. 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 Colesevelam or Olmesartan 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.