Transluminal drug delivery method and device embodiments can include a urethral suppository formulated to prevent or treat diseases of the urethra and surrounding organs, such as interstitial cystitis or urethritis, by enhancing the absorption of a therapeutic agent of the suppository into body tissues without adversely affecting the natural defense mechanisms of these tissues. Adverse effects on the glycosaminoglycan (GAG) barrier can be mitigated or eliminated by the presence of a suitable polysaccharide in the suppository.