Fondaparinux and Papaya: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Fondaparinux
Papaya
No brand names on record
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
A case report documents an elevated INR of up to 7.4 following concomitant use of warfarin with papaya extract in a patient previously stabilized on warfarin1. Other oral anticoagulants may be similarly affected.
Why it happens (mechanism)
Papain may damage the mucous membranes of the gastrointestinal tract, leading to increased bleeding if combined with anticoagulants
Literature reports
1 report — tap to read
a) A 58-year old man, after initiating papaya extract (containing papain) as a weight loss agent and stabilized on an unknown dose of warfarin, was found to have an international normalized ratio (INR) of 7.4 upon hospital admittance for cardiac surgery. Upon discontinuation of both warfarin and papaya extract for 4 days, the INR decreased to 2 1.
Common questions
Can I take Fondaparinux and Papaya together?
Increased risk of bleeding Always confirm with your pharmacist or prescriber before making any change.
How serious is the Fondaparinux and Papaya 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 "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
Questions for your pharmacist
- Does my dose of Fondaparinux or Papaya 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)
- Shaw D, Leon C, Kolev S, et al: Traditional remedies and food supplements: a 5-year toxicological study. Drug Safety 1997; 17:342-356. DOI
Keep reading about Fondaparinux
Keep reading about Papaya
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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