Inquire with your pharmacist about any potential drug-food interactions in your current regimen. For instance, studies indicate that the vitamin K found in green leafy vegetables may reduce the efficacy of blood thinners such as Warfarin and Coumadin. Alcohol can intensify the effects of diabetes medications like insulin. Additionally, grapefruit can result in abnormally high levels of a medicines used to treat high blood pressure -Yisa Bray