Drug interactions
Fosphenytoin + Ivabradine
Severity: Moderate
Fosphenytoin and Ivabradine: 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
Fosphenytoin, via phenytoin, induces CYP3A4 and may substantially reduce ivabradine levels. This can cause loss of heart rate control.
What this interaction means in plain words
Fosphenytoin and Ivabradine 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.
Fosphenytoin belongs to Central Nervous System; Ivabradine belongs to Cardiovascular.
Why it happens
Phenytoin induces CYP3A4, increasing ivabradine clearance.
What to do
Monitor heart rate and symptoms, and adjust ivabradine to effect. Consider an alternative antiarrhythmic or anticonvulsant strategy if needed.
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 Ivabradine
- Atazanavir + Ivabradine Contraindicated
- Clarithromycin + Ivabradine Contraindicated
- Cobicistat + Ivabradine Contraindicated
- Conivaptan + Ivabradine Contraindicated
- Darunavir + Ivabradine Contraindicated
- Diltiazem + Ivabradine Contraindicated
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 Fosphenytoin with Ivabradine?
MediHelp rates the interaction as moderate. Fosphenytoin and Ivabradine 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. Fosphenytoin, via phenytoin, induces CYP3A4 and may substantially reduce ivabradine levels. This can cause loss of heart rate control.
How serious is the interaction between Fosphenytoin and Ivabradine?
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 heart rate and symptoms, and adjust ivabradine to effect. Consider an alternative antiarrhythmic or anticonvulsant strategy if needed.
What other medicines interact with Ivabradine?
MediHelp also lists interactions of Ivabradine with, for example, Atazanavir, Clarithromycin, Cobicistat. The full list is on the Ivabradine page.
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