I want to bump this thread as I think it is good reminder for old ADers and news for the new ADers. If you are getting free samples, ask your doctor about grapefruit with that medicine. If you are buying prescription, ask your good old pharmacist. Also ask if those prescription medicine will conflict with anything else like over the counter medicines, etc.
More on this:
Grapefruit Bad With Some Drugs, Juice Interacts With Many Medicines, Can Have Harmful Effects - CBS News