A porous prosthesis for delivering a medication to the site of implantation. The prosthesis, such as a stent, includes a first porous region and a second porous region and is at least partially formed from a molybdenum-rhenium alloy. The porous regions can have different porosity. A stent includes first, second and third porous region, the first porous region being between the second and third porous regions, and a therapeutic agent is disposed in the first porous region. A stent can also include a solid core and inner and outer porous layers surrounding the core.