Phenytoin and Rivaroxaban: Drug Interaction Guide
Quick answer: This is a major interaction — avoid combining Phenytoin and Rivaroxaban unless specifically directed by your doctor.
How Phenytoin interacts with Rivaroxaban
Phenytoin is a strong inducer of CYP3A4 and P-glycoprotein, lowering rivaroxaban exposure by approximately 50% and risking therapeutic failure (stroke, VTE).
What you should do
Avoid co-administration; switch to a vitamin K antagonist with INR monitoring or change the antiepileptic to a non-inducer (e.g., levetiracetam, lamotrigine).
Key facts
Severity
Major — avoid combination
Mechanism
Phenytoin is a strong inducer of CYP3A4 and P-glycoprotein, lowering rivaroxaban exposure by approximately 50% and riski...
Action
Avoid co-administration; switch to a vitamin K antagonist with INR monitoring or change the antiepileptic to a non-induc...
Frequently asked questions
Can I take Phenytoin and Rivaroxaban together?
No — this combination should generally be avoided. Avoid co-administration; switch to a vitamin K antagonist with INR monitoring or change the antiepileptic to a non-inducer (e.g., levetiracetam, lamotrigine).
What is the severity of this interaction?
The interaction between Phenytoin and Rivaroxaban is classified as Major — avoid combination. Phenytoin is a strong inducer of CYP3A4 and P-glycoprotein, lowering rivaroxaban exposure by approximately 50% and risking therapeutic failure (stroke, VTE).
What should I do if I'm prescribed both?
Avoid co-administration; switch to a vitamin K antagonist with INR monitoring or change the antiepileptic to a non-inducer (e.g., levetiracetam, lamotrigine). Always consult your prescribing clinician — do not stop or change medications without medical guidance.
Last reviewed: by iMedic Medical Editorial Team. Our editorial process.