Orlistat and Warfarin: Drug Interaction Guide

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

How Orlistat interacts with Warfarin

Orlistat can reduce absorption of fat-soluble vitamin K. Reduced vitamin K availability may enhance warfarin anticoagulant effect.

What you should do

Monitor INR when orlistat is started or stopped. Adjust warfarin dose based on INR response.

Key facts

Severity

Moderate — caution required

Mechanism

Orlistat can reduce absorption of fat-soluble vitamin K. Reduced vitamin K availability may enhance warfarin anticoagula...

Action

Monitor INR when orlistat is started or stopped. Adjust warfarin dose based on 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 Orlistat and Warfarin together?

With caution. Monitor INR when orlistat is started or stopped. Adjust warfarin dose based on INR response.

What is the severity of this interaction?

The interaction between Orlistat and Warfarin is classified as Moderate — caution required. Orlistat can reduce absorption of fat-soluble vitamin K. Reduced vitamin K availability may enhance warfarin anticoagulant effect.

What should I do if I'm prescribed both?

Monitor INR when orlistat is started or stopped. Adjust warfarin dose based on INR response. Always consult your prescribing clinician — do not stop or change medications without medical guidance.

Last reviewed: May 28, 2026 by iMedic Medical Editorial Team. Our editorial process.