The inability to attain or sustain an erection of the penis strong enough for fulfilling sexual activity is the hallmark of erectile dysfunction, which is treated with zudena pills (Udenafil). Although Zudena (Udenafil) does not directly relax a cavernous body, it does increase the relaxing impact of nitric oxide through sexual stimulation by blocking PDE-5, which breaks down cGMP in the cavernous body. This results in blood flow to the penile tissues and relaxing of the artery muscles, which leads to an erection. Zudena (Udenafil) increases the likelihood of a successful sexual encounter and erection.