bosentan + iloprost + epoprostenol + macitentan + selexipag

This is a combination of five pharmaceutical agents used in the management of pulmonary arterial hypertension (PAH). Each drug targets a different pathway involved in PAH pathogenesis: - Bosentan and macitentan are endothelin receptor antagonists that block the effects of endothelin-1, a potent vasoconstrictor, by inhibiting its binding to ETA and ETB receptors. This leads to vasodilation and reduced proliferation of vascular smooth muscle cells[6]. - Iloprost and epoprostenol are prostacyclin analogs that mimic endogenous prostacyclin (PGI2), leading to vasodilation, inhibition of platelet aggregation, and antiproliferative effects on vascular smooth muscle. - Selexipag is an oral selective prostacyclin IP receptor agonist that promotes vasodilation and inhibits smooth muscle cell proliferation. These drugs are often used in various combinations as part of sequential or initial combination therapy for PAH to improve exercise capacity, delay clinical worsening, reduce morbidity/mortality risk, and improve hemodynamics[1][4][5]. The use of multiple agents from different classes reflects the complex pathophysiology of PAH involving multiple signaling pathways.