History of Viagra – How it was Formulated

Pfizer had initially started to study Viagra with the purpose of introducing it as a treatment for high blood pressure and angina pectoris. The phase one of the clinical trials that were carried out for the drug indicated little effect on angina while there was an improvement in penile erections.

After the phase two results were obtained, it was clear that the medicine had little effect on angina. After extensive research was conducted on the medication, a patent was put on Viagra in 1996 and was approved for use by the FDA on 27th March 1998. Viagra became the first oral medication to be used for the purpose of treating erectile dysfunction in United States and was made available for sale in 1998.

Viagra is still popular showcased by the annual sale of this ED treatment estimating around 1 billion dollars.

In 1989, Pfizer Scientists named as Peter Dunn and Albert Wood synthesised Sildenafil Citrate, which we now know as the active ingredient of Viagra stating that it was an experiment. This experimental compound was looked upon as a treatment for pulmonary hypertension and angina pectoris. The scientists were hopeful that it would be able to treat pulmonary hypertension and angina.

Two years later, researchers Peter Ellis and Nick Terrett at the Pfizer facility in England found out that drugs, which were PDE 5 inhibitors could help treat erectile dysfunction. Meanwhile phase 1 conducted on Viagra for angina did not produce positive results.

In 1992, while conducting second phase 1 trial on Viagra for its effect on angina, revealed that this pill was able to treat erectile problems. Phase 2 of clinical trials conducted on this pill, as far as treating angina was concerned, revealed mild effects for haemodynamic, which meant a functioning in mechanics related to blood circulation. This proved Viagra to be an ineffective medication as far as treating angina…

Taking a hint from the 1992 study conducted on sildenafil, the Bristol facility of Pfizer in 1993 conducted a pilot study on it to treat erectile dysfunction in men. The participants involved were asked to take sildenafil doses three times a day for a week.

A year later, in 1994, another pilot study was conducted on sildenafil citrate to observe its effects on impotence. It was found that one dose of sildenafil per day was capable of treating penile erections, which gave the American pharmaceutical company Pfizer an encouragement to take this study further.

Since the year 1994 till 1997, 4500 men volunteered to get tested in overall 21 clinical trials conducted on sildenafil for the same purpose (to check how effective it was as an impotence treatment). The result came out that sildenafil, renamed as Viagra was safe and effective in this role as an impotence treatment.

In 1997, Pfizer filed for a New Drug Application for Viagra (NDA 020895) with the FDA. The agency opted for a review on a priority basis.

The success came in 1998 when FDA approved Viagra for treating erectile dysfunction, the first oral medication to be approved clinically for treating impotence.