Drug interactions
omeprazole + warfarin
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Overview
Omeprazole may increase warfarin exposure, raising INR and bleeding risk; effect is variable and most evident after starting, stopping, or changing omeprazole dose.
Mechanism of action
CYP inhibition (primarily CYP2C19, to a lesser extent CYP2C9) reduces warfarin metabolism → ↑ anticoagulant effect.
Clinical management
Monitor INR more frequently when initiating, discontinuing, or changing omeprazole; adjust warfarin dose as needed. Educate patients to report bleeding/bruising.
Drug reference
References
- Prilosec (omeprazole) Prescribing Information — FDA Label
- Coumadin (warfarin) Prescribing Information — FDA Label
- Omeprazole and warfarin Interactions — Drugs.com
Frequently asked questions
Can I take omeprazole with warfarin?
The interaction is rated: Moderate. Omeprazole may increase warfarin exposure, raising INR and bleeding risk; effect is variable and most evident after starting, stopping, or changing omeprazole dose.
How serious is the interaction between omeprazole and warfarin?
The interaction is rated: Moderate. Evidence level: High.
How is the interaction between omeprazole and warfarin managed?
Monitor INR more frequently when initiating, discontinuing, or changing omeprazole; adjust warfarin dose as needed. Educate patients to report bleeding/bruising.
Why do omeprazole and warfarin interact?
CYP inhibition (primarily CYP2C19, to a lesser extent CYP2C9) reduces warfarin metabolism → ↑ anticoagulant effect.
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