So, a medical product “Viagra” (VIAGRA) developed by firm Pfizer International Inc., is the first accepted through a mouth pharmaceutical means in tablets which shows significant and authentic efficiency at vast majority of patients with frustration of erection. The active substance of a preparation is citrate of sildenafil. The preparation is issued in the form of tablets on 25, 50 and 100 mg which contain, accordingly, on 25, 50 and 100 mg citrate of sildenafil.
Unlike other ways of erectile dysfunction treatment which provide carrying out of injections in a penis or other medical procedures, “Viagra” is a simple, convenient and easily applied preparation. At use of “Viagra” you simply accept one tablet when plan sexual contact.
As to the mechanism of “Viagra” action it consists in an increase of the blood quantity coming in a penis that helps the man to cause natural erection.”Viagra” operates only when the man experiences natural sexual excitation and when the sexual intercourse is finished, the penis naturally comes back in the weakened condition. In other words, “Viagra” operates only on natural mechanisms of erection occurrence and there is its indisputable novelty and a secret of huge popularity in it. How “Viagra” has been invented?
In the history of medicine there are many facts when occurrence of surprising opening was result of accidental supervision or finds. Two brightest examples till now are an opening x-ray radiation and antibiotics.
In 1895 the German scientist Wilhelm Konrad Rentgen paid attention to an unusual green luminescence in the darkness of objects which shortly before it were close with a worked high-voltage cathodic tube for some time.
Also he paid attention to that there was a light-striking of the packed photographic film which also was nearby from a worked high-voltage tube. These unexpected supervisions had allowed the ingenious physicist to come out with the assumption of radiation availability which earlier was not known to mankind. Later on, as is known, this courageous assumption had been completely confirmed.
The history of antibiotics opening is a sequence of even more surprising concurrences. In 1928 the British researcher Alexander Fleming incidentally detected, that a kind of dirty mould destroyed almost all types of bacteria which he grew up for bacteriological experiments. However instead of subjecting the laboratory dishes for cultivation of bacteria of sterilization and to begin experiments anew, Fleming had studied properties of a dirty mould in the most careful manner which to us is known now entitled ” Penicillin “. So antibiotics which have made revolution in medicine had been opened.
The discovery of “Viagra” became, apparently, the third greatest “accidental” opening in medicine. That fact testifies to it also, that all the discoveries about which there had been told above, awarded the Nobel Prize. The same high award in the fall of 1998 the researchers who had opened, besides other things, properties of a preparation “Viagra” had been awarded. The history of “Viagra” began in 1992 in Great Britain, in the place Pfiser the Sandwich, during pharmacological researches of firm ” Pfiser”. Researchers were carrying out clinical tests of new medicinal substance – Citrate Sildenafil which was developed as means for treatment of some cordial illnesses.
Scientists counted on that citrate of sildenafil will assist the increase of blood inflow to a cardiac muscle and decrease in arterial pressure. However it was noted, that citrate of sildenafil did not render essential influence neither on blood circulation in a cardiac muscle (myocardium), nor on arterial pressure.
There were, that many patients of a male who participated in research, refuse to return sildenafil tablets, despite of the termination of testing. The reason for refusal at all these patients was one – all of them noted themselves sharp improvement of erection quality. Thus, despite of the minimal influence of a new medicine on blood circulation in a myocardium, sildenafil caused perceptible blood inflow to a man’s genitals. The researchers of pharmacological company ” Pfiser ” concerned to this unexpected property citrate sildenafil with due attention and managed to distinguish a powerful tool in it against erection disturbances. The new preparation received the name “Viagra” – the name was born as though as a result of merge of the words «Vigor» (authority, energy, force) and Niagara – the most powerful waterfall in Northern America.
Since 1993 the long-term clinical tests necessary for confirming of “Viagra” properties began. As a result of these tests high efficiency of “Viagra” for treatment of impotence and a high security of this preparation were proved. And as the natural ending – on March, 27th, 1998 Department of the USA on the foodstuffs and medicines approved application of “Viagra”