Possible Interaction: Cholestyramine Resin and Vitamin K

“Examples of the former include … of the bioavailability of vitamin K by antibiotics, … oils or cholestyramine ; oestrogens, diuretics and hypolipidaemic agents such as clofibrate may influence vitamin K-dependent clotting factor synthesis, and drugs which affect haemostasis, e.g. via platelet function, will enhance the anticoagulant effect of warfarin.”

“Although it has been long known that in theory the use of cholestyramine can cause coagulopathy due to reduced absorption of vitamin K , only a few cases have been reported.”

“ Cholestyramine enabled the use of very low doses of sc vitamin K1 (2 mg total) with subsequent attainment of a therapeutic International Normalized Ratio in 39 h.”