New pharmacotherapies for pulmonary hypertension: where do they fit in?

Pulmonary arterial hypertension (PAH) is a rare, progressively worsening disease characterized by dysfunction among endothelial and smooth muscle cells within the pulmonary vasculature with a resultant increase in pulmonary vascular resistance, right ventricular maladaptation and failure, and ultimately early death. The three major therapeutic classes of medications available to treat PAH act as either prostacyclin analogs or endothelin receptor antagonists (ERAs) or by increasing local nitric oxide (NO) levels by means of phosphodiesterase type 5 inhibitors. Several recent trials have investigated the use of oral prostanoid therapy, next-generation ERAs, and soluble guanylate cyclase stimulators (to increase NO levels) as well as novel formulations of pre-existing therapies. The goal of this manuscript is to briefly review established therapies and then discuss recent developments and practical considerations in each of the major drug classes.