Abstract
Pulmonary arterial hypertension (PAH) is a progressively fatal disease of the small pulmonary arteries. In the last two decades, pharmacotherapeutic advances have improved prognosis. Standard treatment of PAH includes anticoagulants, diuretics, digoxin, and calcium channel blockers. Advanced treatment of PAH includes phosphodiesterase type 5 inhibitors, endothelin antagonists, and prostanoids. Combination therapy can produce additive and synergistic benefit. However, drug interactions may occur among PAH therapies or between medications indicated for PAH and agents used for concomitant illnesses. These interactions may necessitate medication adjustment or are serious enough to limit treatment options. Pulmonary arterial hypertension (PAH) is a complex disorder of the small pulmonary arteries. It is characterized by vascular proliferation and obstructive remodeling, which reduces blood flow through the pulmonary arterial circulation, increases pulmonary vascular resistance, and eventually causes right heart failure. The hemodynamic definition of PAH is a resting mean pulmonary arterial pressure (mPAP) of ≥25 mmHg and a pulmonary capillary wedge pressure (PCWP) of ≤15 mmHg.1,2.