Drug interactions
Mefenamic acid + Triamterene
Severity: Major
Mefenamic acid and Triamterene: 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
Triamterene combined with an NSAID has been linked to acute kidney injury and hyperkalemia. NSAIDs reduce renal prostaglandins, which lowers renal perfusion and potassium excretion while triamterene retains potassium. The diuretic effect may also be weakened.
What this interaction means in plain words
Mefenamic acid and Triamterene 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; Triamterene belongs to Cardiovascular.
Why it happens
NSAID-mediated renal vasoconstriction and reduced potassium excretion add to the potassium-sparing action of triamterene.
What to do
Avoid the combination where possible; if used, monitor serum potassium and renal function closely and keep NSAID use short. Ensure adequate hydration.
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 Triamterene
- Amiloride + Triamterene Contraindicated
- Eplerenone + Triamterene Contraindicated
- Potassium citrate / citric acid + Triamterene Contraindicated
- Potassium citrate + Triamterene Contraindicated
- Spironolactone + Triamterene Contraindicated
- Aceclofenac + Triamterene Major
Frequently asked questions
Can I take Mefenamic acid with Triamterene?
MediHelp rates the interaction as major. Mefenamic acid and Triamterene 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. Triamterene combined with an NSAID has been linked to acute kidney injury and hyperkalemia. NSAIDs reduce renal prostaglandins, which lowers renal perfusion and potassium excretion while triamterene retains potassium. The diuretic effect may also be weakened.
How serious is the interaction between Mefenamic acid and Triamterene?
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 the combination where possible; if used, monitor serum potassium and renal function closely and keep NSAID use short. Ensure adequate hydration.
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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