Warfarin resistance and enteral feedings: 2 case reports and a supporting in vitro study

This study investigated whether an interaction between common enteral feeding products and warfarin exists. Two clinical cases of apparent interaction spurred a supporting in vitro study. Both the clinical cases and the in vitro study showed that several enteral feeding products bind warfarin, reducing the bioavailability of the drug. The binding appears to occur between warfarin and the protein component of the feeding product. This clinically important interaction is likely when warfarin and enteral feeding products are used concurrently. Clinicians should be aware of this potential interaction and monitor the therapy closely, particularly when enteral feeding is discontinued.