History of discovery

 Opening of the first of the drugs sildenafil issued under the patented name "Viagra" was probably the third greatest "accidental" discovery in medicine - after the discovery of X-rays and penicillin. These discoveries were awarded the Nobel Prize. The same high award in autumn 1998 were awarded to researchers who discovered, among other things, the properties of the drug "Viagra". 

The history of "Viagra" has started in 1992 in the UK, in the town Pfayzers Sandwich, in the course of pharmaceutical research firm Pfizer. The researchers conducted clinical trials of a new drug substance - sildenafil citrate, which was developed as a means to treat certain heart ailments. 

Scientists had hoped that sildenafil citrate will help to increase blood flow to the heart muscle and reduce blood pressure. However, it was observed that sildenafil citrate, has no significant effect either on blood circulation in the heart muscle (myocardium), or on blood pressure. At the same time revealed that many male patients who participated in the study refused to return the tablets sildenafil, despite the end of testing. The reason for failure in all these patients had one - they all pointed in his dramatic improvement in the quality of erections. Thus, despite the minimal impact of new drugs on blood circulation in the myocardium, sildenafil caused significant blood flow to male genitals. 

Researchers at pharmaceutical company Pfizer took this unexpected property of sildenafil citrate with due attention and were able to recognize in it a powerful tool to combat erectile dysfunction. A new drug called "Viagra" - the name was born as a result of the merger would be the words "Vigor" (power, energy, force) and the Niagara - the most powerful waterfall in North America. 

Since 1993 began extensive clinical trials necessary to demonstrate the properties of "Viagra". As a result of these tests proved the high effectiveness of Viagra for treating impotence and high safety of this drug. And as a logical final - March 27, 1998 U.S. Department of Food and Drug approved the use of "Viagra". The action of the drug "Viagra" evaluated more than 3000 men aged 19 to 87 years in studies of erectile dysfunction, held all over the world. Length erection disorders in these patients averaged 5 years (from 6 months to 26 years), and disorders of erection have been organic, psychogenic and mixed organic and psychogenic nature. 

The results of these studies indicate that the drug "Viagra" is effective for restoration of erectile function and improve the performance of successful intercourse with a large number of patients, including at a number of diabetic patients with spinal cord injuries and other associated clinical conditions as well as in patients receiving simultaneously a number of medicines.