Epimers and isomers of tetrazole-containing rapamycin analogs and a pharmaceutically acceptable salt or prodrug thereof, are immunomodulatory agents and are useful in the treatment of restenosis and immune and autoimmune diseases. Also disclosed are cancer-, fungal growth-, restenosis-, post-transplant tissue rejection- and immune- and autoimmune disease-inhibiting compositions and a method of inhibiting cancer, fungal growth, restenosis, post-transplant tissue rejection, and immune and autoimmune disease in a mammal. One particular preferred application of such isomers and epimers of tetrazole containing rapamycin and 42-Epi rapamycin analogs is in medicated devices and local vascular delivery wherein the stability and lipid solubility and subsequently diffusion through tissue and cell membranes are essential to the success of rapamycin containing combination devices.