Pulmonary hypertension (PH) is a specific clinical group of severe and rare diseases with similar morphological, hemodynamic, and therapeutic characteristics. Despite the fact that there have been international conciliative documents and advances in drug therapy for PH, the long-term prognosis of the disease in these patients remains rather poor. Clinical trials have demonstrated that bosentan therapy in patients with PH improves pulmonary hemodynamics and exercise endurance and delays the development of the disease. According to the data of long-term studies, as compared to the historical control, bosentan used as a first-line drug can improve survival in PH patients.