Drug interactions
Hydralazine + Mefenamic acid
Severity: Moderate
Hydralazine and Mefenamic acid: 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 such as mefenamic acid can blunt the blood pressure-lowering effect of hydralazine. They cause sodium and fluid retention and reduce vasodilatory prostaglandins, which opposes hydralazine's vasodilation.
What this interaction means in plain words
Hydralazine and Mefenamic acid 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.
Hydralazine belongs to Cardiovascular; Mefenamic acid belongs to Musculoskeletal.
Why it happens
Pharmacodynamic antagonism through inhibition of vasodilatory prostaglandin synthesis and renal sodium and water retention.
What to do
Monitor blood pressure when an NSAID is started or used regularly, and adjust antihypertensive therapy if needed. Use the shortest NSAID course at the lowest effective dose.
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
Other interactions of Hydralazine
- Amifostine + Hydralazine Major
- Aceclofenac + Hydralazine Moderate
- Acemetacin + Hydralazine Moderate
- Aldesleukin + Hydralazine Moderate
- Avanafil + Hydralazine Moderate
- Benzphetamine + Hydralazine Moderate
Frequently asked questions
Can I take Hydralazine with Mefenamic acid?
MediHelp rates the interaction as moderate. Hydralazine and Mefenamic acid 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 such as mefenamic acid can blunt the blood pressure-lowering effect of hydralazine. They cause sodium and fluid retention and reduce vasodilatory prostaglandins, which opposes hydralazine's vasodilation.
How serious is the interaction between Hydralazine and Mefenamic acid?
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 when an NSAID is started or used regularly, and adjust antihypertensive therapy if needed. Use the shortest NSAID course at the lowest effective dose.
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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