Drug interactions
NSAIDs + 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
Additive bleeding risk (GI/intracranial). NSAIDs impair platelet function and injure GI mucosa; some may variably affect INR.
Mechanism of action
Primarily pharmacodynamic: COX-1–mediated platelet inhibition and GI mucosal injury → bleeding. Possible PK effects (protein binding/CYP2C9 competition) with certain NSAIDs → INR changes.
Clinical management
Avoid NSAIDs if possible. Prefer acetaminophen (limit ≤2–3 g/day; monitor INR if higher doses or ≥3 days). If NSAID required, consider celecoxib with PPI; use lowest dose/shortest duration. Check INR 3–5 days after start/stop and monitor for bleeding.
Drug reference
References
- Warfarin (Coumadin) Prescribing Information — FDA Label
- Warfarin: Drug Interactions — Lexicomp
- Warfarin and other vitamin K antagonists: Drug and dietary interactions — UpToDate
Frequently asked questions
Can I take NSAIDs with warfarin?
The interaction is rated: Major. Additive bleeding risk (GI/intracranial). NSAIDs impair platelet function and injure GI mucosa; some may variably affect INR.
How serious is the interaction between NSAIDs and warfarin?
The interaction is rated: Major. Evidence level: High.
How is the interaction between NSAIDs and warfarin managed?
Avoid NSAIDs if possible. Prefer acetaminophen (limit ≤2–3 g/day; monitor INR if higher doses or ≥3 days). If NSAID required, consider celecoxib with PPI; use lowest dose/shortest duration. Check INR 3–5 days after start/stop and monitor for bleeding.
Why do NSAIDs and warfarin interact?
Primarily pharmacodynamic: COX-1–mediated platelet inhibition and GI mucosal injury → bleeding. Possible PK effects (protein binding/CYP2C9 competition) with certain NSAIDs → INR changes.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.