Over the past decade different effective treatment options for use in pulmonary arterial hypertension (PAH) have been developed. Due to multiple pathophysiological pathways in PAH and unsatisfactory overall results with the use of monotherapy in a substantial number of PAH patients, there is a pharmacological rationale for combination therapy. The currently approved substances target the prostacyclin, the endothelin and the NO (nitric oxide) -pathways. Those agents have shown a varying degree of improvement in different categories of PAH associated limitations like hemodynamics, exercise capacity, functional class, and quality of life. However, clinical worsening over time is still significant in most patients irrespective of the treatment utilized. The recently published ESC-ERS (European Society of Cardiology and European Respiratory Society) guidelines on pulmonary hypertension suggest the use of combination therapy in patients who do not respond adequately to monotheapy. This article reviews and critically discusses the available data on combination therapy in PAH.
Keywords: Combination therapy, endothelin receptor antagonists, phosphodiesterase-5-inhibitors, prostanoids, pulmonary hypertension, randomized controlled trials, open-label, nitric oxide, epoprostenol