Drug interactions
Mefenamic acid + Methyclothiazide
Severity: Moderate
Mefenamic acid and Methyclothiazide: moderate 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
NSAIDs can reduce the antihypertensive and diuretic effect of thiazides and increase the risk of renal impairment, particularly with volume depletion. Potassium changes are variable.
What this interaction means in plain words
Mefenamic acid and Methyclothiazide can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Why it happens
NSAID inhibition of renal prostaglandins causes sodium and water retention and reduced renal perfusion, opposing thiazide action.
What to do
Monitor blood pressure, renal function and electrolytes, and ensure adequate hydration. Adjust the diuretic dose if control worsens.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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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
Frequently asked questions
Can I take Mefenamic acid with Methyclothiazide?
MediHelp rates the interaction as moderate. Mefenamic acid and Methyclothiazide can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. NSAIDs can reduce the antihypertensive and diuretic effect of thiazides and increase the risk of renal impairment, particularly with volume depletion. Potassium changes are variable.
How serious is the interaction between Mefenamic acid and Methyclothiazide?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor blood pressure, renal function and electrolytes, and ensure adequate hydration. Adjust the diuretic dose if control worsens.
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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