Does Clarithromycin Interact With Warfarin?

Name: Does Clarithromycin Interact With Warfarin?
Creator: OmniRx Health

Oral Anticoagulants: Warfarin Use With Caution Oral anticoagulants: Spontaneous reports in the postmarketing period suggest that concomitant administration of clarithromycin and oral anticoagulants may potentiate the effects of the oral anticoagulants.

Reviewed by the OmniRx Health clinical team•Last reviewed Jul 4, 2026

Severity: Moderate

Severity basis: drug interactions section (keywords: caution, may potentiate). Combining Clarithromycin (Macrolide antibiotic) and Warfarin (Vitamin K antagonist anticoagulant) is classified as a moderate interaction.

What to Do

Use this combination with caution. Your prescriber may monitor you more closely or adjust doses.

How This Interaction Works

Interactions like this one can happen when two medicines have overlapping effects, or when one changes how the other is absorbed, broken down, or cleared from the body. Clarithromycin is a macrolide antibiotic and Warfarin is a vitamin k antagonist anticoagulant; together they are documented as a moderate interaction. How much this matters depends on your dose, your other medications, and your overall health.

If You Take Both Medications

If you have been prescribed both Clarithromycin and Warfarin, do not start, stop, or change either medication on your own — some medicines are unsafe to stop suddenly. Tell your prescriber and pharmacist that you take both so they can decide whether the combination is right for you, adjust the dose, monitor you more closely, or suggest an alternative.

From the FDA Label

Oral Anticoagulants: Warfarin Use With Caution Oral anticoagulants: Spontaneous reports in the postmarketing period suggest that concomitant administration of clarithromycin and oral anticoagulants may potentiate the effects of the oral anticoagulants.

Source: FDA structured product labeling (set_id 0be243c6-de02-45dd-8210-cab1bbc8dfa7).

Clarithromycin

Macrolide antibiotic

Brands: Biaxin

View Clarithromycin safety profile

Warfarin

Vitamin K antagonist anticoagulant

Brands: Coumadin, Jantoven

View Warfarin safety profile

Check these against your full medication list in our free Interaction Checker

Frequently Asked Questions

Can you take Clarithromycin and Warfarin together?

Clarithromycin and Warfarin have a documented moderate interaction. Use this combination with caution. Your prescriber may monitor you more closely or adjust doses.

How serious is the Clarithromycin and Warfarin interaction?

It is classified as a moderate interaction, based on the FDA label's drug interactions section (keywords: caution, may potentiate). A moderate interaction can be clinically meaningful and usually calls for monitoring or a dose adjustment.

What should I do if I'm taking both Clarithromycin and Warfarin?

This information is educational — not medical advice.

This page is provided for general educational purposes and summarizes publicly available data from sources such as the U.S. Food & Drug Administration. It is not a substitute for the judgment of a licensed clinician and should not be used to start, stop, or change any medication. It may be incomplete or out of date, and individual circumstances vary. Always talk with your prescriber or pharmacist about your specific medications and health conditions. If you think you may have a medical emergency, call 911.

Questions About Your Medications?

A licensed OmniRx provider can review your full medication list and help you understand what's safe for you — no office visit required.

Other Clarithromycin Interactions

Other Warfarin Interactions

Sources & References

Learn more about where our data comes from and how we write and review medical content.