The Center for Food-Drug Interaction Research and Education, an organization co-managed by the University of Florida, College of Pharmacy, and the Tufts University School of Medicine, has opened a website that helps clinicians (and patients) to identify and analyze possible food-drug interactions. Currently, only interactions of meds with grapefruit juice is available. From the website:
Grapefruit juice appeared on the food-drug interaction radar in the late 1980s when scientists discovered that it contains natural substances that can affect the way certain prescription medications are broken down (metabolized) by an enzyme, known as CYP3A4.
If a person drinks grapefruit juice and takes one of these drugs orally, more of the drug may enter the bloodstream than would have under normal circumstances. This means that grapefruit juice has the potential to enhance the absorption of these certain prescription drugs.