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Warfarin Resistance in a Patient with Short Bowel Syndrome
Author(s) -
Brophy Donald F.,
Ford Susan L.,
Crouch Michael A.
Publication year - 1998
Publication title -
pharmacotherapy: the journal of human pharmacology and drug therapy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.227
H-Index - 109
eISSN - 1875-9114
pISSN - 0277-0008
DOI - 10.1002/j.1875-9114.1998.tb03129.x
Subject(s) - warfarin , medicine , dosing , drug , short bowel syndrome , duodenum , absorption (acoustics) , drug interaction , surgery , anesthesia , gastroenterology , pharmacology , atrial fibrillation , parenteral nutrition , physics , acoustics
Drug therapy in short bowel syndrome can be complicated by inadequate or incomplete absorption of drugs in the small intestine. Many case reports claim that warfarin absorption is not affected by the syndrome. We treated a patient with oral warfarin for recurring deep vein thrombosis; up to 20 mg/day was administered with no increase in the international normalized ratio. Drug‐drug interactions that may prevent absorption, increase metabolism, or antagonize the effects of warfarin were ruled out. Intravenous lipid administration, which is anecdotally reported to precipitate warfarin resistance, may have contributed to the condition, but dosing was less frequent than in published reports. The most probable explanation of warfarin resistance is the reduced surface area for drug absorption secondary to surgical removal of the patient's duodenum and gastrojejunostomy.