Drug Interaction Report

Colesevelam and Obeticholic Acid: Interaction Details

AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature

Obeticholic Acid

Ocaliva Ocaliva®
+

Colesevelam

Welchol WelChol®
Dr. Brian Staiger, PharmD, BCPS
Medically reviewed by
Updated Aug 8, 2026
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Interaction severity
Moderate
Can be significant — usually manageable with monitoring.
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.

Of 49 documented Colesevelam interactions, 19 are rated moderate — including this one.
Onset
rapid
Evidence
theoretical
Severity
Moderate

What happens

Reduced exposure and efficacy of obeticholic acid

Interaction Deep Dive

Concomitant use of obeticholic acid and a bile acid binding resin may reduce the absorption, exposure, and efficacy of obeticholic acid. If use of a bile acid binding resin is required, administer obeticholic acid at least 4 hours before or 4 hours after use, or at as great an interval as possible1.

Why it happens (mechanism)

Decreased availability of bile acids due to their binding to resins

Common questions

Can I take Colesevelam and Obeticholic Acid together?

Reduced exposure and efficacy of obeticholic acid Always confirm with your pharmacist or prescriber before making any change.

How serious is the Colesevelam and Obeticholic Acid interaction?

It is rated moderate. Can be significant — usually manageable with monitoring.

How quickly could this interaction happen?

The documented onset is "rapid". Effects can appear quickly, often within about 24 hours of combining the drugs.

How strong is the evidence for this interaction?

The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.

Questions for your pharmacist

  • Does my dose of Colesevelam or Obeticholic Acid 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 anything you'd monitor while I'm on both?

References (1)

  1. Product Information: OCALIVA oral tablets, obeticholic acid oral tablets. Intercept Pharmaceuticals Inc (per manufacturer), New York, NY, 2016.
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Beyond drug–drug

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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This information is for education, not a substitute for professional medical advice. Do not start, stop, or change any medication without talking to your pharmacist or prescriber.