This medicine is also used to treat erectile dysfunction and signs and symptoms of BPH. The enlarged prostate interferes with the normal flow of urine from the bladder and urinary tract, resulting in lower urinary tract symptoms, such as trouble urinating. By controlling the enzyme, tadalafil helps to maintain an erection after the penis is stroked by increasing blood flow to the penis. What special dietary instructions should I follow? This is high blood pressure that occurs in the main artery that carries blood from the right side of the heart the ventricle to the lungs.Cialis works by increasing blood flow to the penis to help a person get and maintain an erection. It also blocks the PDE5 enzyme, which enhances the effects of nitric oxide . The four main medicines taken by mouth for erectile dysfunction are: Avanafil (Stendra). Sildenafil (Viagra). Tadalafil (Cialis). Vardenafil. These medicines are called PDE5 . Cialis is used for the treatment of erectile dysfunction (ED). It increases blood flow to the penis following sexual stimulation and allows men to keep an erection hard enough for .