What you eat and drink can affect the way your medicines work. Use this guide to alert you to possible "food-drug interactions" and to help you learn what you can do to prevent them.In this guide, a food-drug interaction is a change in how a medicine works caused by food, caffeine, or alcohol.A food-drug interaction can: prevent a medicine from working the way it shouldcause a side effect from a medicine to get worse or bettercause a new side effectA...