Drug Interaction Report

Warfarin and Obeticholic Acid: Interaction Details

A pharmacist-reviewed analysis of the Warfarin and Obeticholic Acid interaction: the documented clinical effects, severity rating, onset, mechanism, and management considerations, with cited references throughout.

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

Warfarin

Coumadin Jantoven
+

Obeticholic Acid

Ocaliva Ocaliva®
Dr. Brian Staiger, PharmD, BCPS
Medically reviewed by
Dr. Brian Staiger, PharmD, BCPS
Updated Aug 8, 2026
Editorial policy · Data sources
LinkedIn
Interaction severity
Major
Potentially serious — often needs a change or close 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 210 documented Warfarin interactions, 160 are rated major — including this one.
Worried about symptoms right now? Contact your pharmacist or prescriber, or call Poison Control at 1-800-222-1222 (US). Call 911 for an emergency.
Onset
unspecified
Evidence
probable
Severity
Major

What happens

Increased warfarin exposure and an altered (increased or decreased) INR

Interaction Deep Dive

Consider the CYP1A2 inhibition potential when starting, stopping, or changing dose of concomitant medications. Closely monitor INR, when a CYP1A2 inhibitor, such as obeticholic acid is used with a CYP1A2 substrate, such as warfarin2. During drug interaction studies, concurrent use of obeticholic acid and warfarin decreased maximum INR. Therefore, exercise caution with concomitant use of obeticholic acid and warfarin. If coadministration is required, monitor INR and adjust the warfarin dose to maintain target range 1.

Why it happens (mechanism)

Inhibition of CYP1A2-mediated metabolism of warfarin

Literature reports

1 report — tap to read

a) During drug interaction studies, coadministration of obeticholic acid 10 mg once daily and single dose warfarin 25 mg resulted in a 13% increase in systemic exposure to S-warfarin and an 11% decrease in maximum INR 1.

Common questions

Can I take Warfarin and Obeticholic Acid together?

Increased warfarin exposure and an altered (increased or decreased) INR Always confirm with your pharmacist or prescriber before making any change.

How serious is the Warfarin and Obeticholic Acid 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.

From our Q&A

Real reader questions about these medications, each personally answered by our pharmacist:

Questions for your pharmacist

  • Does my dose of Warfarin 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 a safer alternative to one of these medications for me?

References (2)

  1. Product Information: OCALIVA(R) oral tablets, obeticholic acid oral tablets. Intercept Pharmaceuticals Inc (per FDA), New York, NY, 2022.
  2. Product Information: WARFARIN SODIUM oral tablets, warfarin sodium oral tablets. Teva Pharmaceuticals (per Dailymed), Parsippany, NJ, 2023. DailyMed
Was this write-up helpful?
Warfarin

Keep reading about Warfarin

All Warfarin interactions (210)
Also serious with: Defibrotide Injection Penicillin V Potassium Cefixime Cyclophosphamide
Obeticholic Acid

Keep reading about Obeticholic Acid

All Obeticholic Acid interactions (25) Obeticholic Acid drug information
Also serious with: Fezolinetant Bendamustine Belzutifan Voriconazole
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:

Warfarin + Activated Charcoal Alfalfa American Ginseng Beer Cannabis Danshen Dong Quai Fasting + 353 more
Obeticholic Acid + Activated Charcoal Black Tea Cocoa Coffee Charcoal Cola Nut European Mandrake Evodia Glucomannan + 19 more

major · moderate · minor — check everything you take with our drug–supplement interaction checker.

Check another combination

Our instant two-drug interaction checker is almost here.

Coming soon

The instant two-drug checker is on its way.

In the meantime, browse the directory below to look up any drug and see its documented interactions.

Still have questions about this combination?

Every question gets a real answer from a licensed pharmacist — free, and usually within a day.

Ask the pharmacist
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.