Table 1.

Evaluating existing therapies for PAH in relation to the components of an ideal therapy.

Drug	Date of EU/FDA approval	Specificity for pulmonary circulation	Targets the underlying cause of PAH	Hemodynamic improvement	Quality of life improvement	Exercise capacity improvement	Clinical outcome improvement	Ease of administration	Cost*	Side effects†
Sildenafil	2005	Unknown	Unknown	Yes119	Possible120	Yes	Possible	Fair	Medium121	Moderate
Tadalafil	2008/2009	Unknown	Unknown	Possible	Yes122	Yes	Yes	Easy	Medium	Moderate
Riociguat	2013	Unknown	Unknown	Yes123	Possible124	Yes	Yes	Fair	Very high	High
Bosentan	2001	Unknown	Unknown	Possible125	Possible126	Yes127	Yes	Fair	Very high	High
Ambrisentan	2007	Unknown	Unknown	Possible128	Yes129	Yes	Yes	Easy	Very high	High
Macitentan	2013	Unknown	Unknown	Yes130	Yes131	Yes	Yes132	Easy	Very high	High
Selexipag	2015	Unknown	Unknown	Yes133	Unproven	Yes	Yes8	Fair	Very high	High
Iloprost	2004	Unknown	Unknown	Yes134	Yes	Yes	Possible135	Difficult	Very high	Moderate
Treprostinil (Oral)	2013	Unknown	Unknown	Unproven	Unproven	Yes136, 137	Possible136	Difficult	Very high	High
Treprostinil (Inhaled)	2009	Unknown	Unknown	Yes138	Yes139	Yes	No	Difficult	Very high	Moderate
Treprostinil (SQ)	2002	Unknown	Unknown	Yes140	Yes	Yes	Possible141	Very difficult	Very high	High
Treprostinil (IV)	2004	Unknown	Unknown	Yes142	Unknown	Yes	Unknown143	Very difficult	Very high	High
Epoprostenol	1995	Unknown	Unknown	Yes33	Yes	Yes	Yes	Very difficult	Very high	High

^*Annual “cost” is stratified as follows: low = < $10,000; medium = $10,000–50,000; high = $50,000–100,000; very high = > $100,000.

^†Side effects are stratified as follows: low = minimal long-term risk with rare side effects; moderate = common side effects but not life-threatening; high = side effects may be serious to the patient or unborn children or side effects commonly lead to treatment discontinuation.