Inhaled treprostinil sodium for the treatment of pulmonary arterial hypertension

Introduction: Inhaled treprostinil sodium, a prostacyclin analog, is the most recent agent to receive FDA approval for the treatment of a fatal orphan disease: pulmonary arterial hypertension (PAH). Areas covered: This article first reviews the data supporting the use of infusion prostacyclin and treprostinil as treatments for PAH. The authors then review inhaled treprostinil sodium: the compound and its properties, initial clinical evidence supporting its use and the pivotal data that support a role for inhaled treprostinil sodium in the treatment of patients with PAH. A broad PubMed literature search was done to identify the most current data on the use of treprostinil for PAH. Inhaled treprostinil received FDA approval to improve exercise tolerance in 2009, following the publication of several studies demonstrating its safety and its beneficial effect on hemodynamics, exercise capacity and quality-of-life measures. Expert opinion: Inhaled treprostinil seems to have a similar efficacy profile as inhaled iloprost, although the demonstrated trough effect on exercise tolerance with treprostinil is an advantage. Perhaps more importantly, the longer half-life makes treprostinil more convenient with four-times-daily dosing. As compared with iloprost, inhaled treprostinil has practical advantages for patients (less frequent dosing, shorter inhalation times, once-daily preparation of the drug delivery device, and easier routine maintenance of the nebulizer), but direct comparisons about efficacy or durability of the treatment effect cannot be made in the absence of carefully controlled trials.