bosentan + ambrisentan

Bosentan + ambrisentan is a combination of two endothelin receptor antagonists (ERAs) used in the management of pulmonary arterial hypertension (PAH). Bosentan is a dual antagonist that blocks both endothelin-A and endothelin-B receptors, while ambrisentan selectively antagonizes the endothelin-A receptor. Both drugs act as vasodilators by inhibiting the effects of elevated endothelin-1, a potent vasoconstrictor implicated in PAH pathogenesis. This combination may be considered for patients with inadequate response to monotherapy or as part of sequential or upfront combination therapy strategies for intermediate- and high-risk PAH patients. The use of two ERAs together is not standard practice due to overlapping mechanisms and increased risk of adverse effects such as peripheral edema, anemia, hepatotoxicity, and drug interactions; most guidelines recommend combining an ERA with agents from other classes (e.g., phosphodiesterase type 5 inhibitors), rather than using two ERAs concurrently[4][5]. There are no approved fixed-dose combinations or branded products containing both bosentan and ambrisentan.