Plasma drug-concentrations in patients with pulmonary arterial hypertension on combination treatment

Introduction: Combination therapy of the phosphodiesterase-type 5 inhibitors (PDE-5i) sildenafil or tadalafil and endothelin receptor antagonists bosentan, ambrisentan, or macitentan may cause mutual pharmacokinetic interactions in patients with pulmonary arterial hypertension (PAH). The objective of this study was to analyse plasma drug concentrations in PAH-patients during different combination treatments.