An anterior urethral stricture is a scar of the urethral epithelium (the urethra’s outside layer of cells) and commonly extends into the underlying corpus spongiosum (a column of erectile tissue that surrounds the urethra). The scar (stricture) is composed of dense collagen and fibroblasts (proteins that form cell-producing connective tissue) and thus contracts in all directions, shortening urethral length and narrowing the diameter of the urethra. Strictures usually do not cause symptoms until the urethra tube is below a certain size.
These agents decrease the contractility of bladder muscle. Multiple formulations are marketed, including flavoxate (Urispas), hyoscyamine sulfate (Anaspaz), trospium chloride (Sanctura), solifenacin succinate (Vesicare), darifenacin hydrobromide (Enablex), oxybutynin chloride (Ditropan), oxybutynin chloride ER (Ditropan XL), Urised (blend of atropine, hyoscyamine, methenamine, methylene blue, phenyl salicylate, and benzoic acid that acts as an antispasmodic and anesthetic and inhibits bacterial growth), and tolterodine tartrate (Detrol), which is also both an antispasmodic and anesthetic.