Consumption of vitamin K-rich nutritional shakes caused acquired warfarin resistance in a hospitalized patient, with INR normalizing after cessation of the shakes.
Case Report (n=1)
Does consumption of vitamin K-containing nutritional shakes cause acquired warfarin resistance in hospitalized patients on warfarin?
Hospitalized patients on warfarin require close monitoring of supplemental nutritional shakes, as those containing vitamin K can cause acquired warfarin resistance.
Purpose: Warfarin is an anticoagulant medication used to prevent thromboembolic events in many conditions, but therapeutic monitoring requires close attention to prevent serious side effects. Resistance to warfarin can be acquired or hereditary, and many foods and medical conditions have been implicated in acquired warfarin resistance, such as supplemental nutrition shakes in this case presentation. Case Summary: A 65-year-old woman with a prior mechanical aortic valve replacement presented for an elective non-cardiac surgery. She was chronically stable at an international normalized ratio (INR) goal of 2.5– 3.5. Surgery was performed without complication, and postoperative INRs were persistently low at 1.5– 1.8, despite escalating warfarin doses up to 15 mg warfarin daily at day 12. After a thorough medication and dietary review, the culprit was identified as Boost Plus Nutritional Drinks, a significant source of vitamin K, that she had consumed only while hospitalized postoperatively. Her INR normalized after stopping the shake consumption. Discussion: This is the first known case of a hospitalized patient who developed acquired warfarin resistance from nutritional shakes. Hospitalized patients routinely require supplemental nutrition, and hospitals have a variety of nutritional shakes available, all of which have varying amounts of vitamin K. A review of available supplemental nutrition shakes revealed MightyShakes as the only brand without a significant amount of vitamin K, but other brands also have relatively small quantities of Vitamin K. Conclusion: Supplement administration requires close attention in hospitalized patients on warfarin. Certain brands of nutritional shakes, like MightyShakes, can be safely utilized in such patients if caution is exercised. Keywords: anticoagulation, vitamin K, nutrition, supplementation
Brandon et al. (Wed,) conducted a case report in Acquired warfarin resistance (n=1). Boost Plus Nutritional Drinks was evaluated on International normalized ratio (INR). Consumption of vitamin K-rich nutritional shakes caused acquired warfarin resistance in a hospitalized patient, with INR normalizing after cessation of the shakes.