Fludrocortisone and Phenytoin Interaction
Drug interaction information between Fludrocortisone and Phenytoin.
Fludrocortisone and Phenytoin have a documented minor interaction in FDA labeling.
FDA drug labeling documents a minor-severity interaction between Fludrocortisone and Phenytoin. This page displays the available source-record category and label text. The category is not an individual risk estimate or medication-combination direction.
How They Interact
Phenytoin speeds up how fast your liver processes fludrocortisone. This can cause the fludrocortisone to leave your system too quickly to work well.
FDA Label Information
Barbiturates, phenytoin, or rifampin – increased metabolic clearance of fludrocortisone acetate because of the induction of hepatic enzymes.
Fludrocortisone Also Interacts With
- Furosemide minor
- Aspirin minor
- Rifampin minor
- Amphotericin B minor
- Ethacrynic Acid minor
Phenytoin Also Interacts With
- Nirmatrelvir/Ritonavir major
- Posaconazole major
- Ranolazine major
- Voriconazole major
- Apixaban moderate
Frequently Asked Questions
What SPL severity band is on file for Fludrocortisone + Phenytoin?
Compiled FDA labeling labels this pair minor. That is a source-record field, not an individual medication-combination decision.
Which drug in this pair has the larger labeled-interaction portfolio?
Phenytoin has 147 labeled pairs on file vs Fludrocortisone's 6. In the minor band specifically: Fludrocortisone has 6 (also Furosemide, Aspirin, Rifampin, Amphotericin B); Phenytoin has 120 (also Atorvastatin, Omeprazole, Simvastatin, Methylphenidate).
What mechanism field is on file for Fludrocortisone and Phenytoin?
Phenytoin speeds up how fast your liver processes fludrocortisone. This can cause the fludrocortisone to leave your system too quickly to work well.
Phenytoin carries more major-labeled pairs than Fludrocortisone
SPL source-record counts only. This page's band is minor · classes on file: Fludrocortisone (Mineralocorticoid); Phenytoin (Anticonvulsant (Hydantoin)).
Phenytoin has 4 major-labeled pairs vs Fludrocortisone's 0. This page itself is in the minor band, not the major band.
0 major · 0 moderate · 6 minor · 6 total
- Other minor peers for Fludrocortisone
- Furosemide
- Aspirin
- Rifampin
- Amphotericin B
4 major · 23 moderate · 120 minor · 147 total
- Other minor peers for Phenytoin
- Atorvastatin
- Omeprazole
- Simvastatin
- Methylphenidate
Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. This registry does not provide individual medication-combination directions.
Read our methodology - how this data is sourced, computed, and verified.