Patient education regarding dietary interactions with warfarin should emphasise maintaining a consistent intake of vitamin K-rich foods, particularly green leafy vegetables, to avoid fluctuations in anticoagulation effect. Patients should be advised not to make sudden or large changes in their consumption of foods high in vitamin K, such as spinach, kale, broccoli, and Brussels sprouts, as these can reduce warfarin’s effectiveness by promoting clotting factors synthesis NICE NG158.
Patients should also be informed about the potential interactions with certain foods and supplements that may either potentiate or diminish warfarin’s anticoagulant effect. For example, cranberry products, alcohol, and some herbal supplements (e.g., ginkgo biloba, St John’s Wort) can alter warfarin metabolism and increase bleeding risk or reduce efficacy Tideman et al. 2015.
It is important to encourage patients to communicate any dietary changes or new supplements to their healthcare provider promptly. Regular monitoring of INR (International Normalised Ratio) is essential to adjust warfarin dosing accordingly and maintain therapeutic anticoagulation NICE NG158.
Patients should be educated on recognising signs of bleeding and advised to seek medical attention if these occur, especially if dietary changes have been made. This proactive approach helps prevent complications related to over- or under-anticoagulation Tideman et al. 2015.