Cialis Soft Tabs (Tadalafil)

Although sildenafil (Viagra), vardenafil (Levitra) and tadalafil (Cialis) inhibits PDE5, tadalafil's distinguishing pharmacologic feature is its longer half-life (17.50 hours) - compared to Viagra (4.0-5.0 hours) and Levitra (4.0-5.0 hours) - resulting in longer duration of action, and that is partly responsible for the nickname "the weekend pill." In addition, its longer half-life is the basis for current research therapeutic use of l tadalafil daily use in relieving pulmonary arterial hypertension. At present, sildenafil (trade name Revatio) is approved in several world regions for the treatment of pulmonary arterial hypertension if consumed three doses a day. Penile erection during sexual stimulation is caused by increased penile blood flow resulting from the relaxation of penile arteries and corpus cavernosum smooth muscle. This response is mediated by the release of nitric oxide (NO) from nerve endings and endothelial cells, which stimulates the synthesis of cGMP in smooth muscle cells. Cyclic GMP relaxes smooth muscle and increases blood flow to the corpus cavernosum.