The active component of Zudena Pills is udenafil, the most recent PDE5 (phosphodiesterase type 5) drug used to treat erectile dysfunction (ED). Zudena, sometimes known as udenafil, is the newly approved ED drug. Urologists prescribe the medication udenafil to treat erectile dysfunction. Among other erectile dysfunction medications, it is a member of the PDE5 inhibitor pharmaceutical class, which also includes vardenafil, tadalafil, sildenafil, and avanafil.