Interactions of Commonly Used Prescription Drugs With Food and Beverages

The purpose of this chapter is to review some of the most common drug interactions with food and beverages. By acting on gastric motility, pH, and drug metabolism, food and beverages can have a variety of effects on the absorption and metabolism of prescription drugs, as well as vitamins and minerals. The clinical significance of these interactions ranges from mild to moderate concern to the possibility of significant reductions in drug action, as is seen with garlic and saquinavir, or an increase in serious adverse events, as is seen with cranberry and warfarin. For interactions that affect drug metabolism through cytochrome P450 isoenzymes such as grapefruit juice, there is wide variability from one patient to another and the risk of dangerous interactions may present in only a few. With the advent of pharmacogenomics, our understanding and perhaps profiling of patients for the gene expression of metabolic enzymes may identify patients most at risk for both beverage–drug and drug–drug interactions.