Medical News Today, "Study Finds Long-term Treatment with Bosentan Improves Outcomes in Pulmonary Arterial Hypertension"

          Pulmonary arterial hypertension (PAH) is a devastating disease that carries a poor prognosis. Untreated, about half of patients die within two years. Only recently have specific medicines for this disease become available. While effective, the first available therapy, epoprostenol, proved difficult for patients to use because it is delivered on a continuous intravenous basis rather than in a pill form.
          Bosentan, a dual endothelin receptor antagonist, is the first approved oral treatment for PAH. In short-term (12-16 week) trials, bosentan has demonstrated improvements in how far patients can walk and how they feel. In order to assess the long-term benefit of bosentan, a recent analysis of long-term data was performed. As reported in the European Respiratory Journal, Vallerie McLaughlin of the University of Michigan and her American and European colleagues compared the survival in bosentan-treated patients to the survival that would have been predicted based on past clinical experience.
          Survival in the treated patients was 96% at one year and 89% at two years. In comparison, the expected survival without treatment was 67% at one year and 58% at two years. After two years of follow-up, 70% of patients were still on bosentan alone, without the need for additional therapies. Although treatment with bosentan was well tolerated, it was associated with a 10% incidence of elevated liver enzymes thereby requiring monthly liver enzyme monitoring by a simple blood test.