Drug interactions
Naproxen + Warfarin
Severity: Major
Naproxen and Warfarin: major interaction.
Last updated
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.
Summary
Naproxen inhibits platelet function and can cause gastric erosions, so bleeding is more likely when it is added to warfarin. Serious gastrointestinal hemorrhage is the main concern, and INR may also change.
What this interaction means in plain words
Naproxen and Warfarin can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Naproxen belongs to Musculoskeletal; Warfarin belongs to Cardiovascular.
Why it happens
Additive effects on hemostasis from NSAID antiplatelet activity and mucosal injury plus warfarin anticoagulation, with possible protein-binding displacement.
What to do
Avoid concomitant use and prefer paracetamol for analgesia. If unavoidable, use the shortest course, add a proton pump inhibitor, and monitor INR and signs of bleeding closely.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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Other interactions of Naproxen
- Ketorolac intranasal + Naproxen Contraindicated
- Ketorolac + Naproxen Contraindicated
- Aceclofenac + Naproxen Major
- Acemetacin + Naproxen Major
- Acetylsalicylic acid + Naproxen Major
- Alteplase + Naproxen Major
Other interactions of Warfarin
- Defibrotide + Warfarin Contraindicated
- Ketorolac + Warfarin Contraindicated
- Abciximab + Warfarin Major
- Acetylsalicylic acid + Warfarin Major
- Adagrasib + Warfarin Major
- Amiodarone + Warfarin Major
Frequently asked questions
Can I take Naproxen with Warfarin?
MediHelp rates the interaction as major. Naproxen and Warfarin can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Naproxen inhibits platelet function and can cause gastric erosions, so bleeding is more likely when it is added to warfarin. Serious gastrointestinal hemorrhage is the main concern, and INR may also change.
How serious is the interaction between Naproxen and Warfarin?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid concomitant use and prefer paracetamol for analgesia. If unavoidable, use the shortest course, add a proton pump inhibitor, and monitor INR and signs of bleeding closely.
What other medicines interact with Naproxen?
MediHelp also lists interactions of Naproxen with, for example, Ketorolac intranasal, Ketorolac, Aceclofenac. The full list is on the Naproxen page.
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