Pharmacologic treatment for pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) has been a disease with limited treatment options and poor prognosis. This article reviews the recent advances that took place in the medical management of PAH.

Sildenafil is a type 5 cGMP-specific phosphodiesterase inhibitor originally developed to treat erectile dysfunction. Multiple uncontrolled and randomized controlled trials have proven that it is useful in the treatment of PAH and it was approved by the US Food and Drug Administration. The switch from continuous intravenous infusion of epoprostenol to subcutaneous infusion of treprostinil has been proven feasible and safe. Bosentan has been shown effective as a monotherapy and it also improves survival in patients with functional classes III and IV. In smaller clinical trials bosentan has improved symptoms in different forms of PAH. Combinations of drugs of different classes such as prostanoids, endothelin receptor blockers and sildenafil are tested, and such a strategy improves both symptoms and survival. Animal models and anecdotal clinical experience suggest the possibility of using imatinib mesylate in PAH.

With the approval of sildenafil, treatment options for this difficult disease have improved significantly. Combinations of drugs of different groups are promising and need further exploration.