What are the components of viagra?
The main active component of Viagara tablets is Sildenafil Citrate. Strictly speaking, what we buy as Viagara by itself is Sildenfil Citrate.
Sildenafil citrate is sold by Pfizer under the name Viagara. viagra and generally under various other names. It is a medicine which is used to treat impotence and pulmonary arterial hypertension (PAH), worked out by the Pfizer pharmaceutical company. Viagara tablets are diamond-shaped and blue with the words "Pfizer" on one side, and "VGR xx" (where xx means "25", "50" or "100", the dose of one tablet in milligrams) on the other side. The main competitors on the market are vardenafil (Levitra) and tadalafil (Cialis).
History
A group of pharmaceutical chemists who worked at Pfizer's Sandwich synthesized the sildenafil (component UK-92,480), Kent research facility. Sildenafil was originally developed for use in angina pectoris (a form of ischaemic cardiovascular illness) and hypertension (high blood pressure). Phase I clinical trials under the direction of Ian Osterloh recommended that the medicine had not big effect on treating angina, but it could stimulate marked penile erections. Pfizer for that reason decided to sell ildenafil for impotence, more than for angina. The Food and Drug Administration patented this medicine in 1996. On the 27 th of March, 1998 the drug was proved for use in erectile dyfunction treatment. It became the first tablet proved to treat impotence in the United States of America, and after one year it was offered for the market in the United States. In some time it became a huge success: sales of Viagara per year in the period 1999-2001 were more than one billion of dollars.
Peter Dunn and Albert Wood were portrayed by British press as the creators of the medicine, a claim which Pfizer disputes. Their names are on the manufacturing patent form of medicine, but this is only for comfort - Pfizer says.
Even though sildenafil can be accessible if a doctor prescribes you this medicine, Bob Dole famously endorsed this drug to customers on US TV and it was a good directly advertisement. In the internet Viagara is offered for sale by multiple sites but before you need to pass "online consultation",a big quantity of web questions. The "viagra" name has become so well known that A lot of fake aphrodisiacs are called by similar name to "viagra", for example "herbal viagra", or which imitates product of Pfizer by coping its real shape and color (real Viagara tablets are blue and have diamond shape). "The Blue Pill" and "Vitamin V" are unofficially known as same drug as viagra but have different nicknames.
In 2011-2013 worldwide Pfizer's sildenafil citrate patent will be expired. The British rights held by Pfizer for the use of PDE5 inhibitors as medicine for impotence was declared invalid in 2000 as a result of obviousness; in 2002the decision was upheld on appeal.