When Fruit and Meds Don’t Mix (February 2009)

If you want to get rid of a sinus infection, don’t wash those antibiotics with a glass of juice. Researchers from Canada’s University of Western Ontario found that orange, grapefruit and apple juices can decrease the effectiveness of certain medicines, such as those for allergies (antihistamines), high blood pressure (beta-blockers), and infections (antibiotics). “These juices contain compounds that prevent the transport of drugs into the bloodstream,” says study author David Bailey, Ph.D. Grapefruit juice may also prevent enzymes from metabolizing the medication, increasing the side effects. To stay safe, swallow your medicine with water and wait four hours before opening a juice carton.