Pulmonary arterial hypertension (PAH)
During its development phase, the manufacturer intended the drug to be used to treat PAH and angina. If the arteries in the chest contract or are blocked, this can cause pain and, if not treated, increases blood pressure and can cause a stroke or heart attack. Viagra is a phosphodiesterase (PDE5) inhibitor. PDE is a chemical messenger found in different parts of the body. It tells an artery to contract. By inhibiting it, arteries dilate. This reduces blood pressure and allows blockages to clear. Testing PDE5, the research staff found men reporting improved sexual performance. This lucky accident launched a great new drug.

The original work on PAH continued and the FDA gave its approval for use in 2005. This new version of the drug now more specifically targets the arteries in the chest and has proved highly effective to relieve pain in adult patients. However, the drug is also being tested on babies who are born with PAH. Obviously, the dose is small but, with careful monitoring while the baby is in the respirator, the early results are very encouraging. The only question is whether long term use will prove safe. Researchers are conducting trials to find out whether physical growth is affected if the baby has lower blood pressure.

Use by sports men and women
It has come as a surprise to those responsible for administering sport at a top level that many professional athletes have been using viagra in their training. The recent BALCO scandal in the US has highlighted the way in which athletes bend the rules on drug use to gain an unfair advantage on the playing field. Because viagra dilates blood vessels, it improves the circulation and carries oxygen to the muscles more quickly. This is said to improve endurance. But this may be just a myth. The World Anti-Doping Agency (WADA) has now commissioned research to prove whether athletes get a real advantage. If the scientific evidence shows unfair benefits, viagra will be added to the list of banned substances. This will have one ironic consequence. Male athletes who suffer from erectile dysfunction will have to find a different way to treat their sexual problems. Perhaps this is the reason why the US administrators for professional sports such as baseball and football have no plans to ban viagra.

Altitude sickness
When people start climbing above sea level, they can begin to experience problems. The higher they go, the thinner the air and so the harder the lungs have to work to extract oxygen. Research carried out in 2007 suggests that viagra may be an effective treatment for high-altitude pulmonary edema (HAPE) - a potentially fatal condition unless the victim can quickly be transported to a hospital at low altitude. So if you are climbing or camping in remote areas at high altitude, you may save your life if you carry viagra with you. The results of the tests show that it rapidly improves your lungs’ ability to absorb oxygen.