Drug interactions
Dronedarone + Fosphenytoin
Severity: Contraindicated
Dronedarone and Fosphenytoin: contraindicated 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
Fosphenytoin is converted to phenytoin, a strong CYP3A4 inducer, which can markedly lower dronedarone concentrations. This may lead to loss of antiarrhythmic effect.
What this interaction means in plain words
Dronedarone and Fosphenytoin are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two.
Dronedarone belongs to Cardiovascular; Fosphenytoin belongs to Central Nervous System.
Why it happens
Induction of CYP3A4 increases dronedarone metabolism.
What to do
Avoid the combination; use an alternative anticonvulsant or antiarrhythmic.
What to ask your pharmacist
- Is there an alternative to one of these two medicines for me?
- If both are essential, who is monitoring me and how often?
- Which symptoms mean I should stop and seek help straight away?
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Other interactions of Dronedarone
- Adagrasib + Dronedarone Contraindicated
- Amiodarone + Dronedarone Contraindicated
- Arsenic trioxide + Dronedarone Contraindicated
- Artemether / lumefantrine + Dronedarone Contraindicated
- Atazanavir + Dronedarone Contraindicated
- Azithromycin + Dronedarone Contraindicated
Other interactions of Fosphenytoin
- Fosphenytoin + Ledipasvir-sofosbuvir Contraindicated
- Fosphenytoin + Lorlatinib Contraindicated
- Fosphenytoin + Lurasidone Contraindicated
- Fosphenytoin + Ranolazine Contraindicated
- Fosphenytoin + Sofosbuvir-velpatasvir-voxilaprevir Contraindicated
- Abiraterone + Fosphenytoin Major
Frequently asked questions
Can I take Dronedarone with Fosphenytoin?
MediHelp rates the interaction as contraindicated. Dronedarone and Fosphenytoin are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two. Fosphenytoin is converted to phenytoin, a strong CYP3A4 inducer, which can markedly lower dronedarone concentrations. This may lead to loss of antiarrhythmic effect.
How serious is the interaction between Dronedarone and Fosphenytoin?
MediHelp rates it contraindicated, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination; use an alternative anticonvulsant or antiarrhythmic.
What other medicines interact with Dronedarone?
MediHelp also lists interactions of Dronedarone with, for example, Adagrasib, Amiodarone, Arsenic trioxide. The full list is on the Dronedarone page.
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