Viagra Question
I’ve been fortunate thus far in life to enjoy healthy erectile function, but I have been treated in the past with a drug called Revatio for difficulty in breathing diagnosed as pulmonary arterial hypertension. When I went to refill a prescription recently, I noticed that the generic substitute was labelled sildenafil citrate, which is the same active ingredient as that in Viagra. What gives?
Answer
In the two decades since Pfizer first introduced Viagra, the little blue pill’s active ingredient sildenafil citrate has been found to have a number of other medicinal properties. One of the first of those to be discovered is its ability to improve respiratory function in patients suffering from pulmonary arterial hypertension, or PAH.
This is a condition in which high blood pressure is localized to the arteries that supply the lungs and heart, making it difficult for patients to breathe normally.
In 2005, the FDA approved Pfizer’s new drug application to market sildenafil citrate in 20-milligram tablets under the brand name Revatio. The sildenafil temporarily dilates the arteries supplying the lungs and heart, allowing near-normal blood flow and easing respiratory difficulties.
Although Revatio was introduced seven years after Viagra, Pfizer’s patent on the brand name drug has already expired, opening the market to generic competition.