Drug interactions
Fluvastatin + Fosphenytoin
Severity: Moderate
Fluvastatin 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
Fluvastatin and phenytoin (the active form of fosphenytoin) are both CYP2C9 substrates, and fluvastatin may inhibit phenytoin metabolism. Phenytoin levels can rise and, with a narrow therapeutic index, may cause toxicity. Phenytoin may also alter fluvastatin exposure.
What this interaction means in plain words
Fluvastatin 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.
Fluvastatin belongs to Cardiovascular; Fosphenytoin belongs to Central Nervous System.
Why it happens
Competitive inhibition of CYP2C9 metabolism of phenytoin by fluvastatin, with possible reciprocal induction effects.
What to do
Monitor phenytoin concentrations and signs of toxicity such as nystagmus and ataxia when starting or stopping fluvastatin. Adjust the fosphenytoin dose accordingly.
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 Fluvastatin
- Cyclosporin + Fluvastatin Major
- Fluvastatin + Gemfibrozil Major
- Fluvastatin + Letermovir Major
- Fluvastatin + Red yeast rice Major
- Apalutamide + Fluvastatin Moderate
- Cholestyramine + Fluvastatin Moderate
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 Fluvastatin with Fosphenytoin?
MediHelp rates the interaction as moderate. Fluvastatin 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. Fluvastatin and phenytoin (the active form of fosphenytoin) are both CYP2C9 substrates, and fluvastatin may inhibit phenytoin metabolism. Phenytoin levels can rise and, with a narrow therapeutic index, may cause toxicity. Phenytoin may also alter fluvastatin exposure.
How serious is the interaction between Fluvastatin 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 phenytoin concentrations and signs of toxicity such as nystagmus and ataxia when starting or stopping fluvastatin. Adjust the fosphenytoin dose accordingly.
What other medicines interact with Fluvastatin?
MediHelp also lists interactions of Fluvastatin with, for example, Cyclosporin, Gemfibrozil, Letermovir. The full list is on the Fluvastatin page.
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