In , Pfizer scientists discovered that sildenafil, which also inhibits the PDE5 enzyme, caused penile erection in males participating in a clinical study of a heart medicine. Popular Cialis The most popular medicines selected by users of our online store with various dosages at a nice price. You should only be treated with one of these products at a time. These are fleeting and usually subside with time. Tadalafil is in a class of medications called phosphodiesterase PDE inhibitors. If you are taking tadalafil to treat erectile dysfunction, you should know that it does not cure erectile dysfunction or increase sexual desire.Tadalafil (Cialis) is used to treat erectile dysfunction (ED, impotence; inability to get or keep an erection), and the symptoms of benign prostatic hyperplasia (BPH; an enlarged prostate) which include difficulty urinating (hesitation, dribbling, weak stream, and incomplete bladder emptying), painful urination, and urinary frequency and urgency in adult men. Cialis lasts up to 36 hours in the body, while Viagra lasts 4–6 hours in the body. Both are taken 30 minutes before sex. Cialis can cause limb pain, while Viagra can cause vision change, rash. Brand names for tadalafil include Cialis. The cost for tadalafil oral tablet 5 mg is around $27 for a supply of 90 tablets, depending on the pharmacy you visit. Quoted prices are for .