Six The phosphodiesterase-five inhibitor sildenafil is licensed for PAH in FC I–IV during the USA and FC II–III in Europe. Endothelin receptor antagonists (ERAs) which includes bosentan, sitaxentan and ambrisentan are oral therapies accredited to be used in PAH. As no oral agent has shown superiority there remains discussion as https://ricardoutldv.weblogco.com/26121876/detailed-notes-on-bosentan