Warfarin and Zafirlukast: Drug Interaction Guide

Quick answer: This combination requires caution. Warfarin and Zafirlukast can be used together with adjustments and monitoring.

Interaction severity: Moderate — caution required

How Warfarin interacts with Zafirlukast

Zafirlukast can inhibit CYP2C9-mediated warfarin metabolism. This may increase warfarin exposure and raise INR.

What you should do

Monitor INR after starting, stopping, or changing zafirlukast. Adjust warfarin dose according to INR response.

Key facts

Severity

Moderate — caution required

Mechanism

Zafirlukast can inhibit CYP2C9-mediated warfarin metabolism. This may increase warfarin exposure and raise INR.

Action

Monitor INR after starting, stopping, or changing zafirlukast. Adjust warfarin dose according to INR response.

Important medical disclaimer: This page provides educational information about drug interactions for general reference. It is not a substitute for professional medical advice, diagnosis, or treatment. Always discuss your specific medications with a qualified healthcare provider before starting, stopping, or changing any treatment. About our editorial team.

Frequently asked questions

Can I take Warfarin and Zafirlukast together?

With caution. Monitor INR after starting, stopping, or changing zafirlukast. Adjust warfarin dose according to INR response.

What is the severity of this interaction?

The interaction between Warfarin and Zafirlukast is classified as Moderate — caution required. Zafirlukast can inhibit CYP2C9-mediated warfarin metabolism. This may increase warfarin exposure and raise INR.

What should I do if I'm prescribed both?

Monitor INR after starting, stopping, or changing zafirlukast. Adjust warfarin dose according to INR response. Always consult your prescribing clinician — do not stop or change medications without medical guidance.

Last reviewed: by iMedic Medical Editorial Team. Our editorial process.