Fluvastatin and Phenytoin Interaction
Drug interaction information between Fluvastatin and Phenytoin.
Fluvastatin and Phenytoin have a documented moderate interaction in FDA labeling.
FDA drug labeling documents a moderate-severity interaction between Fluvastatin and Phenytoin. Major interactions are generally avoided, moderate ones may need monitoring or a dose adjustment, and minor ones are usually low-risk. This page shows the documented mechanism and guidance. Label-documented interactions are not a complete safety review, so always confirm your own medications with a pharmacist or doctor. Educational information, not medical advice.
How They Interact
Fluvastatin can cause the levels of phenytoin in your blood to rise, which may lead to side effects.
What To Do
Your doctor should check your phenytoin blood levels when you start or change your dose of fluvastatin.
FDA Label Information
Caution should be used when prescribing with fluvastatin ( 5.1 , 7.3 , 7.4 ) Glyburide: Monitor blood glucose levels when fluvastatin dose is changed ( 7 ) Phenytoin: Monitor plasma phenytoin levels when fluvastatin treatment is initiated or when the dosage is changed ( 7 ) Warfarin and coumarin derivates: Monitor prothrombin times when fluvastatin coadministration is initiated, discontinued, or the dosage changed ( 7 ) 7.1 Cyclosporine Cyclosporine coadministration increases fluvastatin exposure. 7.7 Phenytoin Concomitant administration of fluvastatin and phenytoin increased phenytoin...
Fluvastatin Also Interacts With
- Clarithromycin major
- Cyclosporine moderate
- Glyburide moderate
- Gemfibrozil moderate
- Niacin moderate
Phenytoin Also Interacts With
- Nirmatrelvir/Ritonavir major
- Posaconazole major
- Ranolazine major
- Voriconazole major
- Apixaban moderate
Frequently Asked Questions
Can I take Fluvastatin and Phenytoin together?
This is a moderate interaction. Your doctor should check your phenytoin blood levels when you start or change your dose of fluvastatin.
How serious is the interaction between Fluvastatin and Phenytoin?
This interaction is classified as "moderate" severity by the FDA. Moderate interactions may worsen your condition or change how your medications work.
Why do Fluvastatin and Phenytoin interact?
Fluvastatin can cause the levels of phenytoin in your blood to rise, which may lead to side effects.
Understanding the Fluvastatin and Phenytoin Interaction
FDA-approved prescribing information for these two drugs flags their combination as a moderate-severity interaction. Fluvastatin belongs to the HMG-CoA Reductase Inhibitor (Statin) class and Phenytoin belongs to the Anticonvulsant (Hydantoin) class - two categories that can collide when co-prescribed. The mechanism described in FDA labeling is: Fluvastatin can cause the levels of phenytoin in your blood to rise, which may lead to side effects. Severity tiers matter: major flags generally advise avoidance, moderate flags often require monitoring or dose adjustment, and minor flags may only call for awareness.
Context around a specific patient determines real-world impact. Fluvastatin has 12 total documented interactions on file in this dataset, and Phenytoin has 147. Each additional medication compounds the interaction surface, which is why pharmacists run full-profile checks rather than evaluating one pair at a time. FDA-derived guidance for this pair is: Your doctor should check your phenytoin blood levels when you start or change your dose of fluvastatin. Timing of doses, renal and hepatic function, age, and other concurrent prescriptions all shape whether a labeled interaction matters clinically.
An interaction flag is not a verdict. A large share of labeled interactions are managed routinely in clinical practice, the fix may be as simple as spacing doses or adding a monitoring test. Others require the prescriber to choose a different medication entirely. This page surfaces FDA-sourced labeling and openFDA data for educational purposes only; it is not medical advice and cannot account for your full clinical picture. Never start, stop, or adjust either Fluvastatin or Phenytoin based on a web page, speak with your prescriber or pharmacist before making any change.
Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. Always consult your healthcare provider about drug interactions.
Read our methodology - how this data is sourced, computed, and verified.