The drug Revatio made by Pfizer is an almost identical copy of the Viagra drug also made by Pfizer. Revatio has been on the market for over a year now and really helps those people who suffer from pulmonary arterial hypertension, a dangerous and eventually fatal lung and heart condition that causes blood vessels to the lungs to be constricted.

The FDA in the United States had already approved the all important sildenafil citrate in Viagra when new research was submitted showing the efficacy of the drug in curing PAH and so the Revatio approval was able to be processed quicker than it would have been normally if it was composed of new compounds that the FDA was unaware of.

Revatio is administered to people with PAH in 25 milligrams doses compared to the 20/50/100 milligram doses for the erectile dysfunction drug Viagra. Revatio also looks different to differentiate it from the diamond shaped blue pill Viagra, coming in a simple round and white shape.

Sildenafil citrate works in Viagra and in Revatio in the same way namely by dilating blood vessels that means in the case of PAH blood can get to the lungs and with erectile dysfunction blood can get to the penis allowing for reduced arterial blood pressure and better erections respectively.

Revatio was extensively tested for FDA approval last year and it was shown in the tests that the patients who had taken the Revatio were able to do more exercise and simple tasks before being out of breath than the ones who were given the placebo. The Revatio also increased the longevity of those PAH sufferers using it and the longer term implications of using Revatio for PAH are still being evaluated and studied by Pfizer and independent researchers.

Other PAH drugs have to be administered by injection or intravenously and the good thing about Revatio is how simple it is to take. The side effects for Revatio are obviously the same as for Viagra namely muscles pain, some flushing and very rarely blue-tinged vision. The researchers said that priapism and sudden erections were not reported in the men that took the Revatio drug. One of the great things about Viagra and sildenafil citrate is that the drug only maintains erections when you want them and doesn't cause them without the physical or mental stimulation that normally cause erections.