Bioavailability of Warfarin in a Patient with Severe Short Bowel Syndrome

Abstract

Acquired warfarin resistance has resulted from altered drug metabolism and excessive vitamin K. A third possible mechanism, decreased gastrointestinal absorption of the drug, was examined in a patient with short bowel syndrome and severe malabsorption who demonstrated transient warfarin resistance. Despite the resistance, bioavailability studies demonstrated normal drug absorption and a prolonged half-life. The parenteral administration of vitamin K proved to be the cause of the prolonged warfarin resistance. (Journal of Parenteral and Enteral Nutrition 10:100-101, 1986)