No More Grapefruit Juice?

I understand that many more drugs than previously thought can have unintended effects if you take them after drinking grapefruit juice. Can you tell me which drugs are affected and whether it is important to avoid grapefruit juice altogether or just not use it to wash down pills? 

Source: Dr. Weil Q and A - January 24, 2013 Category: Consumer Health News Source Type: news