6 The phosphodiesterase-5 inhibitor sildenafil is accredited for PAH in FC I–IV while in the USA and FC II–III in Europe. Endothelin receptor antagonists (ERAs) including bosentan, sitaxentan and ambrisentan are oral therapies licensed for use in PAH. As no oral agent has revealed superiority there stays debate as to https://marioiexnt.blog-eye.com/26111804/detailed-notes-on-bosentan