Sildenafil Citrate 100mg Tablets is a drug for the treatment of erectile dysfunction, belonging to the group of phosphodiesterase inhibitors type 5 (PDE-5). Provides a stable and complete an erection sufficient for sexual intercourse. sildenafil tablets 100mg is an active ingredient of the legendary Viagra, but in Russia it is produced under its “maiden name” (read: under the international nonproprietary name). 100mg sildenafil was synthesized in 1998 and became the first truly effective and safe tablet drug for the treatment of such a common disease as erectile dysfunction. To understand the mechanism of action of Sildenafil 100mg need to go a little further in the biochemical “jungle”. First of all, it should be noted what an important role in the functioning of the cardiovascular system plays endothelial relaxing factor, factor, it is the same nitric oxide (NO). Formed in vascular endothelium, NO penetrates into smooth muscle tissue, where “wakes up” … no, not Herzen, and the enzyme guanylate cyclase. As a result, the cellular concentration of cyclic guanosine monophosphate (abbreviated cGMP), which, in turn, prevents the penetration of calcium ions into cells, which entails a decrease in vascular tone, increases dramatically. But there is also your negative character of the enzyme phosphodiesterase (PDE). He destroys the cGMP that limits the vasodilator effect of NO. To date, it has been established that the most active in this regard is PDE-5. Thus, the suppression of its activity enhances the effects of NO Now it is necessary to understand what is the basis for the development of erection. The condition for its occurrence is the relaxation of the smooth muscle “corset” of the arteries carrying blood to the cavernous bodies of the penis. This relaxation “organizes” NO released by endothelial cells. Sildenafil 100mg potentiates the effects of the latter, removing natural barriers to blood to the penis head. Clinical efficacy of Sildenafil Citrate 100mg Tablets has been demonstrated in a number of large randomized studiesIn one case, after 12 weeks, 76% of Sildenafil 100mg patients had a distinct improvement in erection compared to 22% of placebo patients. The high efficiency of the drug was observed in representatives of different age groups: even in persons over 65 years, the drug worked in 69% of cases. One of the risk factors for erectile dysfunction is hypertension. Sildenafil has a weak hypotensive effect, however, the patients with high blood pressure sitting on antihypertensive drugs do not potentiate the effect of the latter, so they can fight with erectile dysfunction on a General basis. Another key risk factor for erectile dysfunction is Smoking, which has been found in clinical trials, does not affect the effectiveness of sildenafil. The drug has another truly miraculous property: in patients suffering from psychogenic erectile dysfunction, it not only improves erection, but also helps to eliminate depression. Separate conversation about persons who have erectile dysfunction developed diabetes mellitus. This category of patients is hardest to get a therapeutic response to pharmacotherapy. The effectiveness of sildenafil in such cases depends on the severity of diabetes and the presence of complications. However, in such difficult conditions, the drug showed its best side: in one of the clinical studies, improved erections were observed in 69% of patients taking sildenafil (in fairness it should be noted that it was the patients without complications). Thus, sildenafil is definitely a “working” drug: its effectiveness does not decrease over time, which makes it possible for long-term pharmacotherapy. Side effects of the drug are usually mild and appear only at the beginning of treatment.