Drug interactions
Diclofenac + Warfarin
Severity: Major
Diclofenac and Warfarin: major interaction.
Last updated Sources: US FDA label
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
Diclofenac increases the risk of serious bleeding, especially gastrointestinal, in patients on warfarin. The effect arises mainly from impaired platelet function and mucosal injury rather than a large change in INR.
What this interaction means in plain words
Diclofenac 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.
Diclofenac belongs to Musculoskeletal; Warfarin belongs to Cardiovascular.
Why it happens
Additive hemostatic impairment through NSAID platelet inhibition and gastric mucosal damage combined with warfarin anticoagulation, with possible minor protein-binding or CYP2C9 effects.
What to do
Avoid if possible and use paracetamol or topical options instead. If unavoidable, give the shortest course with a proton pump inhibitor and monitor INR and signs of bleeding.
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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References
Other interactions of Diclofenac
- Diclofenac + Ketorolac Contraindicated
- Diclofenac + Ketorolac intranasal Contraindicated
- Aceclofenac + Diclofenac Major
- Acemetacin + Diclofenac Major
- Alteplase + Diclofenac Major
- Amiloride + Diclofenac 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 Diclofenac with Warfarin?
MediHelp rates the interaction as major. Diclofenac 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. Diclofenac increases the risk of serious bleeding, especially gastrointestinal, in patients on warfarin. The effect arises mainly from impaired platelet function and mucosal injury rather than a large change in INR.
How serious is the interaction between Diclofenac 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 if possible and use paracetamol or topical options instead. If unavoidable, give the shortest course with a proton pump inhibitor and monitor INR and signs of bleeding.
What other medicines interact with Diclofenac?
MediHelp also lists interactions of Diclofenac with, for example, Ketorolac, Ketorolac intranasal, Aceclofenac. The full list is on the Diclofenac page.
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