Over the weekend a meebo patron asked why his doctor advised him against eating grapefruit while on a certain medication. The website for the American Family Physician explains that grapefruit can cause medications to enter your body faster than necessary. This may cause an increased risk of side effects. Please, meebo guest, listen to your doctor and put down the grapefruit.
Here's the link: http://www.aafp.org/afp/2006/0815/p611.html