Balloon catheters that deliver therapeutic agents are functional only for treatment of the arterial anatomy and result in inefficient dispersion of the therapeutic agent to the arterial tissue due to dispersion through the secondary balloon holes under high pressure. A method and drug delivery balloon device for efficient drug delivery to the targeted point of the anatomy comprising a first balloon wholly enveloped by a second balloon composed of a porous membrane that delivers the therapeutic agent to the targeted point upon the introduction of low pressure to the secondary balloon membrane. In the venous anatomy, the drug delivery balloon device interacts directly with the diseased, narrow segment of the venous vessel while not damaging the vessel tissue. Further, in treatment of arteriovenous (AV) fistulas, the drug delivery balloon device allows the physician to choose the appropriate drug and quantity for treating the narrowing (smooth muscle hyperplasia) or blood clots (thrombus burden) in the fistula.
