Phenytoin and Apixaban Interaction
Drug interaction information between Phenytoin and Apixaban.
Phenytoin and Apixaban have a documented moderate interaction in FDA labeling.
FDA drug labeling documents a moderate-severity interaction between Phenytoin and Apixaban. 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 causes your body to get rid of apixaban much faster than it should. This means the medicine may not work well enough to stop blood clots from forming.
FDA Label Information
7.2 Combined P-gp Strong CYP3A4 Inducers Avoid concomitant use of apixaban tablets with combined P-gp and strong CYP3A4 Inducers (e.g., rifampin, carbamazepine, phenytoin, St.
Phenytoin Also Interacts With
- Nirmatrelvir/Ritonavir major
- Posaconazole major
- Ranolazine major
- Voriconazole major
- Aprepitant moderate
Apixaban Also Interacts With
- Clopidogrel moderate
- Aspirin moderate
- Warfarin moderate
- Carbamazepine moderate
- Rifampin moderate
Frequently Asked Questions
What SPL severity band is on file for Phenytoin + Apixaban?
Compiled FDA labeling labels this pair moderate. 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 Apixaban's 12. In the moderate band specifically: Phenytoin has 23 (also Aprepitant, Canagliflozin, Carbidopa/Levodopa, Clarithromycin); Apixaban has 9 (also Clopidogrel, Aspirin, Warfarin, Carbamazepine).
What mechanism field is on file for Phenytoin and Apixaban?
Phenytoin causes your body to get rid of apixaban much faster than it should. This means the medicine may not work well enough to stop blood clots from forming.
Phenytoin carries more major-labeled pairs than Apixaban
SPL source-record counts only. This page's band is moderate · classes on file: Phenytoin (Anticonvulsant (Hydantoin)); Apixaban (Direct Oral Anticoagulant (Factor Xa Inhibitor)).
Phenytoin has 4 major-labeled pairs vs Apixaban's 0. This page itself is in the moderate band, not the major band.
4 major · 23 moderate · 120 minor · 147 total
- Other moderate peers for Phenytoin
- Aprepitant
- Canagliflozin
- Carbidopa/Levodopa
- Clarithromycin
0 major · 9 moderate · 3 minor · 12 total
- Other moderate peers for Apixaban
- Clopidogrel
- Aspirin
- Warfarin
- Carbamazepine
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.