Sildenafil Citrate Therapy for Pulmonary Arterial Hypertension

In this randomized trial involving patients with pulmonary hypertension, sildenafil (an inhibitor of phosphodiesterase type 5) was found to improve exercise capacity and pulmonary hemodynamics. The study was not powered to assess mortality, but the findings suggest that sildenafil may have a place in the treatment of symptomatic pulmonary hypertension. In patients with pulmonary hypertension, sildenafil was found to improve exercise capacity and pulmonary hemodynamics. Pulmonary arterial hypertension is defined as a group of diseases characterized by a progressive increase in pulmonary vascular resistance, leading to right ventricular failure and premature death. 1 , 2 Pathobiologic mechanisms of the disease include pulmonary endothelial dysfunction, which leads to impaired production of vasodilators, such as nitric oxide and prostacyclin, and overexpression of vasoconstrictors, such as endothelin-1. 3 , 4 Treatment includes conventional agents (anticoagulants, diuretics, digoxin, and supplemental oxygen, as well as calcium-channel blockers in selected patients), vasodilators, and antiproliferative agents such as prostanoids and endothelin-receptor antagonists, which are targeted at abnormalities of endothelial function. 5 , 6 Four agents are currently approved . . .