Viagra (Sildenafil)

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    Description

    Generic Viagra(Sildenafil citrate) has revolutionized the way erectile dysfunction is treated the active substance added to the FDA registry in 1998 is rated 42th in the list the prescription drugs sales in the US. The drug is appointed to eliminate ED symptoms of both psychological and physiological nature. Sildenafil represents the class of phosphodiesterase type 5 inhibitors, it’s scope of action is aimed at relaxing smooth muscles in genitalia and enhance the blood flow to the penis to facilitate erection. The preparation helps you to deal with a variety of manifestations: premature ejaculation, insufficient control of erection, sexual fatigue and etc. Apart from ED treatment, the drug is also used in pulmonary arterial hypertension therapy.

    How it works?

    The physiological erection mechanism implies the release of nitric oxide in the cavernous body in the presence of natural excitation. In these conditions the level of cGMP increases, which is accompanied by relaxation of smooth muscle tissues in penis and an increased blood flow.

    Pharmacological mechanisms of action

    Viagra (Sildenafil) doesn’t provide a relaxing action on corpus cavernosum; however, it improves the action of NO release through PDE5 inhibition, the substance that facilitates the breakage of cGMP enzyme. This means that the preparation doesn’t serve as a stimulant of erection it enhances the natural erection in the presence of excitation and excludes the emergence of uncontrolled erections. The clinical efficacy of the substance was evaluated in 21 comprehensive study, each lasting for the period 6 months in up to 3,000 patients of 19 – 87 years old, divided into a several sub-groups. The merits of effectiveness of sildenafil therapy were the IIEF index (also known as the International Index of Erectile function, a standardized method used in sexual health-related areas) and the feedback of participants’ sexual partners. The efficacy of sildenafil citrate was characterized as ability to build and maintain erection, enabling a patient to have a satisfactory sexual intercourse; it was confirmed in all of the above studies as well as in the FDA pre-approval study of sildenafil. The direct correlation between the dosage of the drug and its effectiveness was also confirmed: thus, depending on the dosage, 62, 74 and 82% of patients have managed to improve their sexual function (taking 25, 50 and 100mg of sildenafil, respectively). The results of identical tests in patients from placebo group have revealed the maximum 22% improvement. On average the preparation lasts for 4 hours, while the adverse reactions are observed in under 10% of cases, having mostly non-significant nature.

    How to use Viagra (Sildenafil)

    Viagra(Sildenafil citrate) is recommended to be taken 45 – 60 minutes prior to the anticipated sexual intercoures; however, the onset of action depends on the individual characteristics of a patient, so the time regime adjustments can be performed. The drug must not be taken with fatty foods and alcohol to avoid the risks of side effects and insufficient impact on sexual function. Despite the fact that sildenafil is likely to produce its action with the first intake (62% of clinical trials participants admitted a considerable improvement), you should evaluate the efficacy of the drug after 5th reception (82% of clinical trials participants reported of noteworthy positive changes).