Phosphodiesterase Type 5 Inhibitors for Pulmonary Arterial Hypertension

A 46-year-old-woman presents with exertional dyspnea and syncope and receives a diagnosis of idiopathic pulmonary arterial hypertension. Treatment with sildenafil is recommended. Sildenafil and tadalafil are phosphodiesterase type 5 inhibitors that ameliorate pulmonary arterial hypertension by increasing levels of cyclic guanosine monophosphate in the smooth-muscle cells of the pulmonary artery.