A stenting system for insertion into the lumen of a body duct or vessel for delivering a therapeutic agent to a treatment site on the duct or vessel. The stenting system includes an a tubular stent member having a lumen there through to allow the passage of material, an outer membrane attached to the stent at least a portion of which is porous to the therapeutic agent to allow the agent to pass to the treatment site, an inner membrane attached to the stent which is nonporous to the therapeutic agent to prevent the agent from entering the lumen of the stent, and a chamber located between the inner and outer membranes for holding the therapeutic agent. The therapeutic agent in the chamber may diffuse through the porous portion of the membrane and be deposited directly on the body site.