Drug interactions
Modafinil + Warfarin
Severity: Moderate
Modafinil and Warfarin: 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
Modafinil has been reported to alter warfarin effect, with INR increases described in isolated cases. Labeling advises monitoring because the direction and size of the change are uncertain.
What this interaction means in plain words
Modafinil and Warfarin 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.
Modafinil belongs to Central Nervous System; Warfarin belongs to Cardiovascular.
Why it happens
Modafinil inhibits CYP2C19 and induces CYP3A4, so effects on warfarin metabolism are variable and not well characterized.
What to do
Monitor INR more frequently when modafinil is started, changed or stopped, and adjust the warfarin 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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Modafinil and Warfarin, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
Other interactions of Warfarin
- Defibrotide + Warfarin Contraindicated
- Ketorolac + Warfarin Contraindicated
- Abciximab + Warfarin Major
- Acetylsalicylic acid + Warfarin Major
- Adagrasib + Warfarin Major
- Amiodarone + Warfarin Major
Other interactions of Modafinil
Frequently asked questions
Can I take Modafinil with Warfarin?
MediHelp rates the interaction as moderate. Modafinil and Warfarin 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. Modafinil has been reported to alter warfarin effect, with INR increases described in isolated cases. Labeling advises monitoring because the direction and size of the change are uncertain.
How serious is the interaction between Modafinil and Warfarin?
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 INR more frequently when modafinil is started, changed or stopped, and adjust the warfarin dose accordingly.
What other medicines interact with Warfarin?
MediHelp also lists interactions of Warfarin with, for example, Defibrotide, Ketorolac, Abciximab. The full list is on the Warfarin page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
