History of the creation of Viagra
The creators of Viagra.
- Sildenafil citrate (which is the main active substance of sildenafil 100mg), nowadays known as Viagra and was synthesized in 1989 by Peter Dunn, Albert Wood, and other employees in Pfizer research center in England.
Names Andrew Bell, Dr David Brown and Dr Nicholas Turret (also Pfizer employees in the same research center) is also of great importance for the history of Viagra because they originally helped to discover that chemical compounds belonging to the class of pyrazolopyrimidinone were useful in the treatment of heart problems such as angina pectoris.
Turret received in 1991 a British patent for sildenafil as a cure for the heart, and some experts consider him as the father of Viagra. Turret claims that his team discovered how useful it can be material, but Dunn and Wood actually synthesized the drug in 1989, brought together all the ingredients in one tablet of Viagra.
Dunn and Wood in favor of the use of the patent for the production of sildenafil citrate, although assigned to Pfizer argues that numerous employees contributed to the discovery of compounds YUK- 92,480 / sildenafil citrate / Viagra.
The primary purpose of Viagra.
Then the experts tested this drug for sildenafil side effects.
Viagra was initially studied for use in hypertension (high blood pressure) and angina pectoris (a symptom of ischemic heart disease). In Phase I clinical trials under the direction of Ian Osterloh, it was revealed that the drug has little effect on angina, but it can cause an improvement of penile erection.
After 2nd phase trial, sildenafil has not confirmed the promising results in the treatment of angina, Pfizer decided to continue the study of the substance in the treatment of erectile dysfunction. The drug was patented in 1996 and approved for use in the treatment of erectile dysfunction American organization by the Food and Drug Administration (FDA) March 27, 1998. Viagra was the first oral treatment for erectile dysfunction, approved in the United States, will be on sale in the United States in the same year. Sales of Viagra continue to exceed 1 billion in revenue. Annually.
Promotion and popularity of Viagra.
Many celebrities and politicians have appeared on television, radio and print ads to help sell the product, including former United States Senator Bob Dole and soccer star Pele, in Latin America and Europe. Political analyst Rush Limbaugh, former baseball player Rafael Palmeiro and former NASCAR driver Mark Martin racing were also representatives.
Viagra has become so popular that in 1998 a lot of companies, many of which are not in the United States, it became illegal to manufacture and sell such products as “herbal viagra”, “viagra professional” or “generic Viagra.” Pfizer does not grant permission to these companies to use the name “Viagra” for these non FDA approved drugs. Fake versions of Viagra are usually cheaper, but may contain unknown ingredients and give an unknown result, so are the health risks.
In 2000, Viagra sales accounted for 92% of global sales agents for erectile dysfunction. By 2007, the global market share was only 50% due to several factors, including the appearance of a 2003 FDA-approved products – Levitra and Cialis, as well as many clones and fakes. Pfizer patents on sildenafil expire between 2011 and 2013.
Many lawsuits were filed by Pfizer, including a claim for $ 110 million from Joseph Moran, car dealer from New Jersey, who claimed that he crashed his car and two parked after taking Viagra, which caused him to see blue lightning byuschie it of the fingers, and then he lost consciousness. Joseph Moran then went home to his Ford Thunderbird.
At this time, the most popular dosage of this medicine to use is sildenafil citrate 100 mg.
History of the creation of Viagra: chronology.
Pfizer scientists (including Peter Dunn and Albert Wood) was synthesized sildenafil and classified it as eksperementalonoe compound SK-92, SK-480 92, 480, is said to be useful in the treatment of angina and high blood pressure. Scientists had hoped that it can act as a vasodilator, and to be useful in the treatment of cardiovascular diseases such as hypertension and angina.
Researchers at Pfizer’s Sandwich, Research Centre (Peter Ellis and Nick Turret) note that the drug inhibits the enzyme PDE-5 may be useful in the treatment of erectile dysfunction. The first phase of clinical researchers gave inconclusive results in the treatment of angina.
The second phase of studies of sildenafil as a treatment for angina reveals another side effect-erection of the penis. With regard to angina, there is only weak effects for hemodynamics.
Experimental studies of sildenafil citrate for erectile dysfunction treatment are carried out in Bristol, England. Subjects receive it three times a day for a week.
The second study as Viagra for erectile dysfunction treatment indicates that once daily, it can enhance an erection. Pfizer accelerates learning program sildenafil citrate for the treatment of impotence.
1994 – 1997
A total of 20 clinical trials conducted with almost 4500 people. They argue that Viagra (now as a remedy for impotence) is safe and effective.
Pfizer submits papers for approval of Viagra FDA, who agrees to give priority consideration reserved for drugs that provide great advances in treatment, or provide vital medical care.
FDA approves Viagra as the first oral medication for the treatment of erectile dysfunction.
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