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Moxifloxacin and Warfarin Interaction

Drug interaction information between Moxifloxacin and Warfarin.

Moxifloxacin and Warfarin have a documented minor interaction in FDA labeling.

FDA drug labeling documents a minor-severity interaction between Moxifloxacin and Warfarin. 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

Moxifloxacin

Fluoroquinolone Antibiotic

Drug B

Warfarin

Vitamin K Antagonist (Anticoagulant)

How They Interact

Moxifloxacin can increase the blood-thinning effects of warfarin, which makes it easier for you to bleed or bruise.

What To Do

Your doctor should perform regular blood tests to check your clotting levels while you are taking both medications.

FDA Label Information

( 2.2 , 7.1 , 12.3 ) Warfarin Anticoagulant effect enhanced. 7.2 Warfarin Fluoroquinolones, including moxifloxacin hydrochloride, have been reported to enhance the anticoagulant effects of warfarin or its derivatives in the patient population. Therefore the prothrombin time, International Normalized Ratio (INR), or other suitable anticoagulation tests should be closely monitored if moxifloxacin hydrochloride is administered concomitantly with warfarin or its derivatives [see Adverse Reactions (6.2) and Clinical Pharmacology (12.3) ].

Warfarin Also Interacts With

View all Warfarin interactions →

Frequently Asked Questions

Can I take Moxifloxacin and Warfarin together?

This is a minor interaction. Your doctor should perform regular blood tests to check your clotting levels while you are taking both medications.

How serious is the interaction between Moxifloxacin and Warfarin?

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 Moxifloxacin and Warfarin interact?

Moxifloxacin can increase the blood-thinning effects of warfarin, which makes it easier for you to bleed or bruise.

Understanding the Moxifloxacin and Warfarin Interaction

FDA-approved prescribing information for these two drugs flags their combination as a minor-severity interaction. Moxifloxacin belongs to the Fluoroquinolone Antibiotic class and Warfarin belongs to the Vitamin K Antagonist (Anticoagulant) class - two categories that can collide when co-prescribed. The mechanism described in FDA labeling is: Moxifloxacin can increase the blood-thinning effects of warfarin, which makes it easier for you to bleed or bruise. 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. Moxifloxacin has 10 total documented interactions on file in this dataset, and Warfarin has 163. 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: Your doctor should perform regular blood tests to check your clotting levels while you are taking both medications. 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 Moxifloxacin or Warfarin 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.