Warfarin is a vitamin K inhibitor, so foods high in vitamin K will diminish the drug’s effectiveness. Ginkgo biloba and cranberry juice should be avoided. Alcohol should be discouraged while taking warfarin—no set amount is considered safe, although danger increases with higher amounts of alcohol consumption. Since warfarin metabolism is strongly affected by diet, patients should strive to maintain a consistent diet by eating similar foods day to day and week to week. This will help keep international normalized ratio (INR) stable and will prevent frequent dosage adjustments.