A drug delivery apparatus and method for iontophoretically delivering a drug locally to internal body tissue. The iontophoretic delivery apparatus and method include a current source producing a net flow of current in a desired direction with high frequency waveforms which enhance delivery and minimize side effects typically associated with iontophoresis.
The invention contemplates positioning a drug delivery device in a body passageway or within body tissue and then selectively introducing a selected drug so that it is iontophoretically transported across a drug transport wall of the device for direct contact with the passageway wall or body tissue. A further aspect of the present invention involves treating a dilated vessel in the area of a stenotic lesion with a fixative or other drug to render the vessel biologically inert and to form a biological stent or prevent restenosis using specifically selected drugs. A still further aspect of the present invention involves treating a tumor or local or regional tissue mass with antitumor sensitizing agents, biological modifiers, antibiotics or other types of drugs by iontophoretic delivery of the drug to the tumor or tissue area directly or through the passageway wall.