Cabozantinib and Warfarin: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Warfarin
Cabozantinib
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
Increased risk of bleeding
Interaction Deep Dive
Concomitant use of cabozantinib and warfarin may increase warfarin exposure and increase the risk of bleeding via inhibition of CYP2C9 and CYP2C19-mediated metabolism of warfarin1. Closely monitor INR and adjust dosage as needed.
Why it happens (mechanism)
Inhibition of CYP2C9 and CYP2C19-mediated metabolism of warfarin by cabozantinib
Literature reports
1 report — tap to read
a) A 64-year-old male with metastatic renal cell carcinoma receiving stable warfarin doses of 35 to 37.5 mg/week and maintaining an INR of 2.2 to 3.1 for over 3 months initiated on third-line treatment with cabozantinib experienced increases in INR to 9.7 and 18 necessitating vitamin K and fresh frozen plasma. Withholding warfarin for 2 doses did not rectify his INR increases. He had scant nose bleeds, but no other signs of bleeding. INR corrected to 2 within 7 days of cabozantinib discontinuation and the patient continued on his previously stable dosage of 37.5 mg/week 1.
Common questions
Can I take Cabozantinib and Warfarin together?
Increased risk of bleeding Always confirm with your pharmacist or prescriber before making any change.
How serious is the Cabozantinib and Warfarin interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "delayed". Effects tend to build up gradually over days to weeks.
How strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Cabozantinib or Warfarin need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (1)
- Foxx-Lupo WT, Sing S, Alwan L, et al: A drug interaction between cabozantinib and warfarin in a patient with renal cell carcinoma. Clin Genitourin Cancer 2016; 14(1):e119-e121. PubMed
Keep reading about Warfarin
Keep reading about Cabozantinib
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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