Drug interactions
Diclofenac + Mefenamic acid
Severity: Major
Diclofenac and Mefenamic acid: 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
Using two NSAIDs together provides no added benefit and increases the risk of GI ulceration and bleeding, renal injury and cardiovascular events.
What this interaction means in plain words
Diclofenac and Mefenamic acid 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; Mefenamic acid belongs to Musculoskeletal.
Why it happens
Additive inhibition of COX-1 and COX-2, reducing gastroprotective prostaglandins, platelet function and renal perfusion.
What to do
Avoid combining NSAIDs; choose one agent at the lowest effective dose and consider gastroprotection in at-risk patients.
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 Mefenamic acid
- Ketorolac intranasal + Mefenamic acid Contraindicated
- Ketorolac + Mefenamic acid Contraindicated
- Aceclofenac + Mefenamic acid Major
- Acemetacin + Mefenamic acid Major
- Acetylsalicylic acid + Mefenamic acid Major
- Alteplase + Mefenamic acid Major
Frequently asked questions
Can I take Diclofenac with Mefenamic acid?
MediHelp rates the interaction as major. Diclofenac and Mefenamic acid 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. Using two NSAIDs together provides no added benefit and increases the risk of GI ulceration and bleeding, renal injury and cardiovascular events.
How serious is the interaction between Diclofenac and Mefenamic acid?
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 combining NSAIDs; choose one agent at the lowest effective dose and consider gastroprotection in at-risk patients.
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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