Ciprofloxacin and Warfarin interaction

Ciprofloxacin and Warfarin: both prescribing labels describe an interaction that usually calls for monitoring, a dose change, or spacing the doses.

Moderate

Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.

What the FDA labels say

From the Ciprofloxacin label · effective 2026-06-30

Moderate

Monitor prothrombin time and INR frequently during and shortly after co- administration of ciprofloxacin with an oral anti-coagulant (for example, warfarin).

Drug interactionsnames WarfarinView label on DailyMed
Moderate

Anti-coagulant drugs Use with caution (Increase in anticoagulant effect) The risk may vary with the underlying infection, age and general status of the patient so that the contribution of ciprofloxacin to the increase in INR (international normalized ratio) is difficult to assess.

Drug interactionsby drug classView label on DailyMed
Moderate

Warfarin Anticoagulant effect enhanced.

Drug interactionsby drug classView label on DailyMed

From the Warfarin (Warfarin Sodium) label · effective 2026-06-24

Moderate

…oxandrolone, sulfinpyrazone, tigecycline, voriconazole, zafirlukast aprepitant, bosentan, carbamazepine, phenobarbital, rifampin CYP1A2 acyclovir, allopurinol, caffeine, cimetidine, ciprofloxacin, disulfiram, enoxacin, famotidine, fluvoxamine, methoxsalen, mexiletine, norfloxacin, oral contraceptives, phenylpropanolamine, propafenone, propranolol, terbinafine,…

Drug interactionsnames CiprofloxacinView label on DailyMed

Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.

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Not medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.