Drug interactions
Mefenamic acid + Venlafaxine
Severity: Major
Mefenamic acid and Venlafaxine: 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
Venlafaxine with an NSAID increases the risk of upper gastrointestinal bleeding compared with either drug alone. The risk is highest in older adults and those with prior GI bleeding.
What this interaction means in plain words
Mefenamic acid and Venlafaxine 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.
Mefenamic acid belongs to Musculoskeletal; Venlafaxine belongs to Central Nervous System.
Why it happens
Serotonin reuptake inhibition depletes platelet serotonin and impairs aggregation, adding to NSAID platelet inhibition and mucosal damage.
What to do
Avoid if possible; otherwise use the lowest NSAID dose for the shortest time with a proton pump inhibitor. Monitor for GI bleeding and anemia.
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 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
Other interactions of Venlafaxine
- Isocarboxazid + Venlafaxine Contraindicated
- Methylene blue + Venlafaxine Contraindicated
- Phenelzine + Venlafaxine Contraindicated
- Procarbazine + Venlafaxine Contraindicated
- Rasagiline + Venlafaxine Contraindicated
- Safinamide + Venlafaxine Contraindicated
Frequently asked questions
Can I take Mefenamic acid with Venlafaxine?
MediHelp rates the interaction as major. Mefenamic acid and Venlafaxine 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. Venlafaxine with an NSAID increases the risk of upper gastrointestinal bleeding compared with either drug alone. The risk is highest in older adults and those with prior GI bleeding.
How serious is the interaction between Mefenamic acid and Venlafaxine?
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; otherwise use the lowest NSAID dose for the shortest time with a proton pump inhibitor. Monitor for GI bleeding and anemia.
What other medicines interact with Mefenamic acid?
MediHelp also lists interactions of Mefenamic acid with, for example, Ketorolac intranasal, Ketorolac, Aceclofenac. The full list is on the Mefenamic acid page.
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