| Tadalafil is an oral drug that is used for treating impotence (the inability to attain or maintain a penile erection). When the cGMP is destroyed by another enzyme, phosphodiesterase-5, the blood vessels return to their normal size, blood leaves the penis, and the erection ends. Tadalafil prevents phosphodiesterase-5 from destroying cGMP so that cGMP stays around longer. Although the scientists were not testing the chemical compound IC351 for erectile dysfunction, the compound seemed to have a side effect which could potentially be worth millions, if not billions of dollars. Soon Icos received its very first patent in 1994 on IC351, and the clinical trials of phase 1 took place in 1995. In 1997, phase 2 clinical studies began and Icos performed its first study on patients with erectile dysfunction. Phase 2 lasted about two years, and after that phase 3 began.The persistence of cGMP leads to a more prolonged engorgement of the penis with blood.Take Cialis exactly as your doctor prescribes. Cialis comes in different doses (5 mg, 10 mg, and 20 mg). Tadalafil is an oral drug that is used for treating impotence (the inability to attain or maintain a penile erection). It is in a class of drugs called phosphodiesterase inhibitors that also includes sildenafil (Viagra) and vardenafil (Levitra). For most men, the recommended starting inability to attain or maintain a penile erection). It is in a class of drugs called phosphodiesterase inhibitors that also includes sildenafil (Viagra) and vardenafil (Levitra).Erection of the penis is caused by the filling of the penis with blood. Filling Cialis dose is 10 mg. Cialis should be taken no more than once a day. Your doctor will prescribe the dose that is right for you. Drug Class and Mechanism It is in a class of drugs called phosphodiesterase inhibitors that also includes sildenafil (Viagra) and vardenafil (Levitra).Erec... |