Need Info on Echinacea

I am trying to research information on echinacea. I have recently heard from a couple of different doctors that echinacea cleanses the blood and so would that also mean if you were taking medication such as high blood pressure medication, that this would eliminate it from your system?
If you have any info that might help to answer these questions or if you could direct me somewhere (books, websites, etc.) I would appreciate it.

'Cleans the blood' or 'purifies the blood' are old folkloric terms. It may have described agents that help the body eliminate toxins from the blood, perhaps by stimulating the kidneys. It may also refer to herbs that stimulate the immune system, thus ridding the blood of contagiums. In the context of echinacea, it is this latter sense of the term that is implied by the doctors. Echinacea has powerful immune-stimulating properties that can help ward off colds. Stimulating the immune system will not cause the body to eliminate your medication for high blood pressure.
Good sources of information are Steven Foster's book "Echinacea, Nature's Immune Enhancer" or Christopher Hobb's booklet, "Echinacea: The Immune Herb!" (both available from Richters).
By the way, you might look into the healthful effects of garlic. Garlic has been recommended for treatment of high blood pressure.