Degra - Degra relaxes muscles and increases blood flow to particular areas of the body. Degra under the name Viagra is used to treat erectile dysfunction (impotence) in men. Another brand of Degra is Revatio, which is used to treat pulmonary arterial hypertension and improve exercise capacity in men and women. Do not take Viagra while also taking Revatio, unless your doctor tells you to. Degra may also be used for purposes not listed in this medication guide. Degra is a medication for the treatment of erectile dysfunction. This drug restores impaired erectile function and provides a natural response to sexual stimulation. Degra is a potent and selective inhibitor of cGMP-specific phosphodiesterase type 5 (PDE5) which is responsible for the breakdown of cGMP in the cavernous body. This medicine has no direct relaxing effect on corpus cavernosum, but enhances the relaxing effect of active nitric oxide in this tissue. When sexually aroused the local release of NO under the influence of Degra leads to the inhibition of PDE-5 and increase of cGMP in the cavernous body, resulting in relaxation of smooth muscles and increasing blood flow to the cavernous body. Degra may cause mild and transient violation of distinguishing colors (blue / green). Alleged violations of the mechanism of color vision is PDE6 oppression, which is involved in the transmission of light in the retina. Erections are controlled by the parasympathetic nervous system. Upon sexual stimulation, a decrease in vascular resistance is mediated by acetylcholine and nitric oxide resulting in vasodilation. The hemodynamic mechanism of an erection is comprised of five stages. During the latent stage, arterial and carvernous smooth muscle relaxation occurs. Vasodilation results in high levels of blood flow causing the penis to grow to its full size. This stage is called tumescence. During the full-erection stage, blood flow fills penis sinusoids and outflow is restricted. This is followed by the rigid-erection phase during which the cavernous muscles contract causing the penis to become rigid. Little blood flow occurs during this stage. During the final stage, detumescence, the cavernous muscles relax and blood flows out of the penis. Erectile dysfunction may occur when there is insufficient blood supply to the penis or when the penis is unable to prevent outflow of blood from the penis. Degra is a specific inhibitor of PDE5, an enzyme responsible for the breakdown of cGMP to 5’-GMP. Increased levels of cGMP stimulate vasodilation and facilitate the generation and maintenance of erections. These vasodilatory effects also help decrease symptoms of PAH. Sildenfail also exhibits some activity against PDE6 (10 times less potentcy compared to PDE5), a PDE isoform found predmoninantly in the retina. This activity is responsible for the blue tinged vision experienced by users of sildenafil.
