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This is an independent website that provides information about Cialis. It is not affiliated with Eli Lilly and Company, the manufacturers of Cialis, and does not represent Eli Lilly and Company in any way whatsoever.
This section includes technical information about Cialis (tadalafil), the class of drug that it is and how it works.
The active ingredient in the Cialis tablet is a compound called tadalafil. Tadalafil works by inhibiting phosphodiesterase type 5 (PDE5). It has a longer half life at 17.5 hours, than either Viagra or Levitra, which each have half lifes of between four to five hours. This longer half life is what uniquely makes Cialis work for a longer duration of time. For this very reason, Cialis is currently being researched as a once a day treatment for pulmonary arterial hypertension.
An erection is caused by increased blood flow to the penis during sexual stimulation. This response is tempered by the release of nitric oxide (NO) from nerve terminals and endothelial cells, which in turn stimulates the synthesis of Cyclic GMP (cGMP) in smooth muscle cells. cGMP causes the smooth muscle to relax and increases the blood flow to the corpus cavernosum. Inhibiting phosphodiesterase type 5 (PDE5) enhances erectile function by increasing the amount of cGMP. Tadalafil inhibits PDE5. Because sexual stimulation is required to commence the local release of nitric oxide, the inhibition of PDE5 has no effect when the sexual stimulation is not taking place.
The recommended starting dose of Cialis in the majority of patients is 10 mg, taken as required before anticipated sexual activity (but no more than once daily). The dose may be increased to 20 mg or decreased to 5 mg on your doctor's advice, based on your response to it and how well your system tolerates the drug.
In order to help men with erectile dysfunction who have sex regularly (two or more times per week), Lilly ICOS have evaluated the benefits and risks of once a day Cialis use. Thus, In June 2007, the EMEA approved low-dose (2.5 mg and 5 mg) Cialis to be used as a daily therapy for men with erectile dysfunction.
Formal Chemical Name (IUPAC)
(6R-trans)-6-(1,3-benzodioxol-5-yl)- 2,3,6,7,12,12a-hexahydro-2-methyl-pyrazino [1', 2':1,6] pyrido[3,4-b]indole-1,4-dione