Drug interactions
Amlodipine-valsartan + Fosphenytoin
Severity: Moderate
Amlodipine-valsartan 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
Fosphenytoin is converted to phenytoin, a CYP3A4 inducer that can lower amlodipine concentrations. Blood pressure control may be reduced.
What this interaction means in plain words
Amlodipine-valsartan 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.
Amlodipine-valsartan belongs to Cardiovascular; Fosphenytoin belongs to Central Nervous System.
Why it happens
Induction of CYP3A4-mediated amlodipine metabolism.
What to do
Monitor blood pressure when starting or stopping fosphenytoin and increase the amlodipine dose if control is inadequate.
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 Amlodipine-valsartan
- Aliskiren + Amlodipine-valsartan Contraindicated
- Amlodipine-valsartan + Sparsentan Contraindicated
- Aldesleukin + Amlodipine-valsartan Major
- Amifostine + Amlodipine-valsartan Major
- Amiloride + Amlodipine-valsartan Major
- Amlodipine-valsartan + Benazepril 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 Amlodipine-valsartan with Fosphenytoin?
MediHelp rates the interaction as moderate. Amlodipine-valsartan 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. Fosphenytoin is converted to phenytoin, a CYP3A4 inducer that can lower amlodipine concentrations. Blood pressure control may be reduced.
How serious is the interaction between Amlodipine-valsartan 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 blood pressure when starting or stopping fosphenytoin and increase the amlodipine dose if control is inadequate.
What other medicines interact with Amlodipine-valsartan?
MediHelp also lists interactions of Amlodipine-valsartan with, for example, Aliskiren, Sparsentan, Aldesleukin. The full list is on the Amlodipine-valsartan page.
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