New research showing the benefits of novel drug therapies for pulmonary arterial hypertension (PAH), a serious lung disease, was presented at the 26th Annual Meeting and Scientific Sessions of the International Society for Heart and Lung Transplantation (ISHLT), held recently in Madrid, Spain.

Researchers discussed the results of new trials for several drugs, including the endothelin antagonists Sitaxentan and Bosentan, the prostenoids Trepostenil and Prostacyclin, and Viagra (sildenafil citrate), marketed as Revatio for PAH.

"It is an extremely exciting time for physicians involved in the care of patients with pulmonary arterial hypertension because of the explosion of novel drugs within the last few years," said Paul Corris, professor of thoracic medicine at the University of Newcastle upon Tyne and director of the North of England Pulmonary Vascular Service. "Although these drugs cannot yet be considered a cure for pulmonary arterial hypertension, results of medical therapy are extremely encouraging for patients who have this serious disease and there is good evidence to show that patients who otherwise would have required urgent listing for lung transplantation may be treated satisfactorily in the interim with these drugs."

PAH is caused when the smaller blood vessels in the lungs become more resistant to blood flow, thereby forcing the right ventricle of the heart to work harder to pump enough blood through the lungs. Viagra, for example, causes the pulmonary arteries to dilate, which lessens the lungs' resistance to blood flow and reduces the workload of the heart.