Drug interactions
Digoxin + Fosphenytoin
Severity: Moderate
Digoxin and Fosphenytoin: 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, to which fosphenytoin is converted, may reduce digoxin concentrations and its effect. Phenytoin and digoxin can also both affect cardiac conduction.
What this interaction means in plain words
Digoxin and Fosphenytoin 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; Fosphenytoin belongs to Central Nervous System.
Why it happens
Phenytoin induces P-glycoprotein and possibly other clearance pathways, lowering digoxin exposure.
What to do
Monitor serum digoxin levels and clinical response when starting or stopping fosphenytoin, and increase the digoxin dose if needed. Monitor ECG during intravenous loading.
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 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 Fosphenytoin
- Dronedarone + Fosphenytoin Contraindicated
- Fosphenytoin + Ledipasvir-sofosbuvir Contraindicated
- Fosphenytoin + Lorlatinib Contraindicated
- Fosphenytoin + Lurasidone Contraindicated
- Fosphenytoin + Ranolazine Contraindicated
- Fosphenytoin + Sofosbuvir-velpatasvir-voxilaprevir Contraindicated
Frequently asked questions
Can I take Digoxin with Fosphenytoin?
MediHelp rates the interaction as moderate. Digoxin and Fosphenytoin 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, to which fosphenytoin is converted, may reduce digoxin concentrations and its effect. Phenytoin and digoxin can also both affect cardiac conduction.
How serious is the interaction between Digoxin and Fosphenytoin?
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 clinical response when starting or stopping fosphenytoin, and increase the digoxin dose if needed. Monitor ECG during intravenous loading.
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.
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