Zudena is a brand of medicine used to treat erectile dysfunction in men. Its primary ingredient is Udenafil, a medication classified as phosphodiesterase type 5 (PDE5) inhibitor. Udenafil works by boosting blood flow to the penis during sexual stimulation, allowing men to obtain and sustain an erection. Zudena pills may not be suitable for all individuals. Individual responses vary, so if it does not work for you, talk to your doctor about alternate treatments.