Paroxetine and Warfarin: Drug Interaction Guide

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

Interaction severity: Moderate — caution required

How Paroxetine interacts with Warfarin

Paroxetine impairs platelet serotonin-mediated aggregation and may modestly inhibit CYP2C9-mediated warfarin metabolism, increasing the risk of bleeding without consistently changing the INR.

What you should do

Monitor INR within a week of starting or stopping paroxetine and counsel patients to report any unusual bruising, epistaxis, or gastrointestinal bleeding.

Key facts

Severity

Moderate — caution required

Mechanism

Paroxetine impairs platelet serotonin-mediated aggregation and may modestly inhibit CYP2C9-mediated warfarin metabolism,...

Action

Monitor INR within a week of starting or stopping paroxetine and counsel patients to report any unusual bruising, epista...

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 Paroxetine and Warfarin together?

With caution. Monitor INR within a week of starting or stopping paroxetine and counsel patients to report any unusual bruising, epistaxis, or gastrointestinal bleeding.

What is the severity of this interaction?

The interaction between Paroxetine and Warfarin is classified as Moderate — caution required. Paroxetine impairs platelet serotonin-mediated aggregation and may modestly inhibit CYP2C9-mediated warfarin metabolism, increasing the risk of bleeding without consistently changing the INR.

What should I do if I'm prescribed both?

Monitor INR within a week of starting or stopping paroxetine and counsel patients to report any unusual bruising, epistaxis, or gastrointestinal bleeding. Always consult your prescribing clinician — do not stop or change medications without medical guidance.

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