Bosentan in pulmonary hypertension associated with hypoxaemic lung diseases

Background: Pulmonary hypertension (PH) is associated with limitation of exercise capacity, poor clinical course and reduced survival in chronic, hypoxaemic lung diseases. Bosentan is an oral dual endothelin receptor antagonist with established efficacy in pulmonary arterial hypertension, either idiopathic or associated with other diseases. Treatment experience with the efficacy and safety of bosentan in PH associated with chronic hypoxeamic lung diseases is limited.Methods: This case-series study reports six consecutive patients with chronic hypoxaemia on the basis of COPD, idiopathic pulmonary fibrosis, silicosis, pneumonectomy, or bronchiectasis. All patients were on long-term oxygen therapy.Results: After 12 weeks’ bosentan treatment, mean 6-minute walk distance increased by 44 meters (from 317 ± 40 m to 361 ± 43 m) and two patients had improved their functional class. Mean systolic pulmonary arterial pressure (PAP) decreased from 83 ± 5.3 to 75 ± 6.1 mmHg, mean partial pressure of arterial oxygen (PaO2) increased from 52 ± 2.8 to 62 ± 4.5 mmHg. No patients presented with treatment-related adverse events.Conclusion: Bosentan appears to be effective in enhancing gas exchange function in pulmonary hypertension associated with hypoxaemic lung diseases. These changes paralleled an increase in exercise capacity and functional class. Our experience suggests a possible role of dual endothelin receptor antagonists in the treatment of exercise capacity limitation and disease-related symptoms in chronic hypoxaemic patients.