Drug interactions
Eplerenone + Phenytoin
Severity: Moderate
Eplerenone and Phenytoin: 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
Phenytoin is a strong inducer of CYP3A4 and can substantially lower eplerenone exposure. This may reduce the antihypertensive and heart failure benefits of eplerenone.
What this interaction means in plain words
Eplerenone and Phenytoin 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.
Eplerenone belongs to Cardiovascular; Phenytoin belongs to Central Nervous System.
Why it happens
Phenytoin induces hepatic and intestinal CYP3A4, increasing eplerenone metabolism.
What to do
Monitor blood pressure, potassium and clinical response, and consider eplerenone dose titration or an alternative antiepileptic or agent if efficacy is lost.
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 Eplerenone
- Amiloride + Eplerenone Contraindicated
- Atazanavir + Eplerenone Contraindicated
- Clarithromycin + Eplerenone Contraindicated
- Cobicistat + Eplerenone Contraindicated
- Elvitegravir / cobicistat / emtricitabine / tenofovir df + Eplerenone Contraindicated
- Ensitrelvir + Eplerenone Contraindicated
Other interactions of Phenytoin
- Artemether / lumefantrine + Phenytoin Contraindicated
- Bictegravir + Phenytoin Contraindicated
- Cabotegravir + Phenytoin Contraindicated
- Doravirine + Phenytoin Contraindicated
- Elbasvir / grazoprevir + Phenytoin Contraindicated
- Elvitegravir / cobicistat / emtricitabine / tenofovir df + Phenytoin Contraindicated
Frequently asked questions
Can I take Eplerenone with Phenytoin?
MediHelp rates the interaction as moderate. Eplerenone and Phenytoin 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. Phenytoin is a strong inducer of CYP3A4 and can substantially lower eplerenone exposure. This may reduce the antihypertensive and heart failure benefits of eplerenone.
How serious is the interaction between Eplerenone and Phenytoin?
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, potassium and clinical response, and consider eplerenone dose titration or an alternative antiepileptic or agent if efficacy is lost.
What other medicines interact with Eplerenone?
MediHelp also lists interactions of Eplerenone with, for example, Amiloride, Atazanavir, Clarithromycin. The full list is on the Eplerenone page.
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