Drug interactions
Digoxin + Phenytoin
Severity: Moderate
Digoxin 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 can lower serum digoxin concentrations, which may reduce control of heart rate or heart failure symptoms. Phenytoin also has its own effects on cardiac conduction, so the clinical picture can be complicated.
What this interaction means in plain words
Digoxin 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.
Digoxin belongs to Cardiovascular; Phenytoin belongs to Central Nervous System.
Why it happens
Phenytoin induces intestinal P-glycoprotein and hepatic metabolism, increasing digoxin elimination and reducing its exposure.
What to do
Monitor serum digoxin levels and heart rate or rhythm when phenytoin is started, stopped or changed. Adjust the digoxin dose to clinical response and target concentration.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Digoxin and Phenytoin, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
Other interactions of Digoxin
- Digoxin + Lily of the valley Contraindicated
- Digoxin + Squill Contraindicated
- Adagrasib + Digoxin Major
- Amiodarone + Digoxin Major
- Amlodipine-hydrochlorothiazide-valsartan + Digoxin Major
- Amphotericin b deoxycholate + Digoxin Major
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 Digoxin with Phenytoin?
MediHelp rates the interaction as moderate. Digoxin 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 can lower serum digoxin concentrations, which may reduce control of heart rate or heart failure symptoms. Phenytoin also has its own effects on cardiac conduction, so the clinical picture can be complicated.
How serious is the interaction between Digoxin 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 serum digoxin levels and heart rate or rhythm when phenytoin is started, stopped or changed. Adjust the digoxin dose to clinical response and target concentration.
What other medicines interact with Digoxin?
MediHelp also lists interactions of Digoxin with, for example, Lily of the valley, Squill, Adagrasib. The full list is on the Digoxin page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
