The Bosentan Effects in Inoperable Forms of CTEPH (BENEFIT) study randomized patients to treatment with 62.5 mg bosentan b.i.d for 4 weeks, followed by 125 mg b.i.d. for 12 weeks or placebo. Their average age was 63 years. Bosentan was linked with a significant, 24% reduction in peripheral vascular resistance in 66 evaluable patients, compared with 71 placebo patients. Treatment also significantly boosted cardiac index, and cut NT-proBNP levels and dyspnea scores. Bosentan treatment had no significant effect on 6-minute walk distance.
Another study assessed the acute hemodynamic effect of a single, 25-mg dose of sildenafil in 44 patients with PAH already on chronic bosentan treatment. The results showed that the single sildenafil dose was safe, and after 60 minutes led to a significant drop in pulmonary vascular resistance, total pulmonary resistance, pulmonary artery pressure, and cardiac output.
The fourth study examined the pharmacokinetics of a new formulation of bosentan designed for use in children. Results from 35 patients aged 2–11 years showed that the formulation led to reasonable serum levels and a good safety profile.
“New drugs such as bosentan have dramatically improved outcomes for patients with pulmonary arterial hypertension. It is gratifying to see extension of the research into patients with early disease and in children,” commented Dr. Daniel Jones, professor of medicine and dean of the medical school at the University of Mississippi, Jackson, and president of the American Heart Association.
The data showed 'in a pure cohort of class II patients that early treatment may delay [PAH progression].' DR. RUBIN