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Chitosan potentiation of warfarin effect
Shao-Sung Huang1, Shih-Hsien Sung, Chern-En Chiang
1Division of Cardiology, Taipei Veterans General Hospital and National Yang-Ming University, Taipei, Taiwan.
The Annals of Pharmacotherapy
|October 11, 2007
Summary
Chitosan may increase the blood-thinning effect of warfarin, likely by reducing vitamin K absorption. This interaction, potentially leading to elevated international normalized ratio (INR), warrants awareness among healthcare providers.
Area of Science:
- Pharmacology
- Gastroenterology
- Nutritional Science
Background:
- Warfarin is a common anticoagulant used for conditions like atrial fibrillation.
- Chitosan is a biopolymer with potential effects on nutrient absorption.
Observation:
- An elderly patient on warfarin experienced a significant increase in international normalized ratio (INR) after self-medicating with chitosan.
- The INR normalized after vitamin K administration and chitosan discontinuation, but rose again upon chitosan reintroduction.
Findings:
- Chitosan's chemical properties suggest it may bind lipids and bile acids, potentially impairing vitamin K absorption.
- This mechanism could explain the potentiation of warfarin's anticoagulation effect observed in the case.
Implications:
- This case highlights a previously unreported interaction between warfarin and chitosan.
- Healthcare professionals should consider chitosan as a potential factor when managing patients on warfarin therapy.
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