When a man is sexually stimulated, his body’s normal response is to increase blood flow to his penis to produce an erection. Take tadalafil exactly as directed. What special precautions should I follow? It also dilates blood vessels in the lungs, which lowers the pulmonary artery pressure. There are two different ways to take tadalafil, either daily or on an as needed basis. By controlling the enzyme, tadalafil helps to maintain an erection after the penis is stroked by increasing blood flow to the penis.Tadalafil – Brand names: Cialis, Adcirca. Find out how tadalafil treats erectile dysfunction, pulmonary hypertension and benign prostate enlargement, and how to take it.  · Cialis is a prescription drug used to treat erectile dysfunction and benign prostatic hyperplasia. Learn about its dosages, form, strengths, and more.  · Cialis (tadalafil) is a prescription tablet used for erectile dysfunction and benign prostatic hyperplasia. Learn about dosage, side effects, and more.