Warfarin Resistance Associated with Poor Intestinal Absorption

Has the patient demonstrated a good response to coumadin in the past?

Does the patient respond well to a parenteral dose of coumadin?

Does the patient have a chronic persistent diarrhea?

Does the patient have a history of small bowel resection or bypass surgery affecting the duodenum?

Does the patient have a malabsorption syndrome affecting the proximal small bowel?

Does the patient have an abnormal warfarin absorption study?

Is there another explanation that can explain the warfarin resistance better?