New York Times, "Viagra may get a role as a lung medication"

          Viagra is only one of several drugs approved or being developed for the lung disease. Some doctors and insurance companies say that it has not been proven effective in rigorous clinical trials, whereas other drugs have. Pulmonary hypertension patients use the drug every day and in higher doses than men who use it before sex, they say, potentially raising new risks.
          Though only an estimated 100,000 people in Europe and the United States have pulmonary hypertension, there are three drugs already approved for the condition and others on the way. Executives attribute the high degree of competition for treating such a rare disease to two facts. First, the mechanisms of the disease have become better understood. And second, if a drug has a high enough price and is taken every day, sales can reach several hundred million dollars a year, even in a small group of patients.
          While far from cures for pulmonary hypertension, the new drugs have helped to improve the outlook for patients. "In 1999, what I would have said to you is that 50 percent of patients die within two years of diagnosis," said Rino Aldrighetti, president of the Pulmonary Hypertension Association, a patient group. "Now we are looking at five years."