Drug interactions
Sulfasalazine + Warfarin
Severity: Moderate
Sulfasalazine 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
Sulfasalazine has been reported to increase the anticoagulant effect of warfarin in some patients. Sulfonamide-type drugs can raise INR, and sulfasalazine may also cause blood dyscrasias that add to bleeding risk.
What this interaction means in plain words
Sulfasalazine 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.
Why it happens
Possible inhibition of CYP2C9-mediated warfarin metabolism and/or protein-binding displacement by the sulfonamide moiety; not fully established.
What to do
Monitor INR when starting or stopping sulfasalazine 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 Sulfasalazine 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 14 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
Frequently asked questions
Can I take Sulfasalazine with Warfarin?
MediHelp rates the interaction as moderate. Sulfasalazine 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. Sulfasalazine has been reported to increase the anticoagulant effect of warfarin in some patients. Sulfonamide-type drugs can raise INR, and sulfasalazine may also cause blood dyscrasias that add to bleeding risk.
How serious is the interaction between Sulfasalazine 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 when starting or stopping sulfasalazine 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.
