6 The phosphodiesterase-5 inhibitor sildenafil is certified for PAH in FC I–IV during the USA and FC II–III in Europe. Endothelin receptor antagonists (ERAs) including bosentan, sitaxentan and ambrisentan are oral therapies licensed to be used in PAH. As no oral agent has shown superiority there remains discussion regarding which https://bosentan33840.blogtov.com/6485672/detailed-notes-on-bosentan