how long after doxycycline can i have sex Pulmonary arterial hypertension PAH is characterized by progressive loss of function by the pulmonary vascular bed due to a variety of factors including obliterative vascular lesions, vasoconstriction, and thrombotic occlusion of the pulmonary arteries" rel="bookmark">how long after doxycycline can i have sex Pulmonary arterial hypertension PAH is characterized by progressive loss of function by the pulmonary vascular bed due to a variety of factors including obliterative vascular lesions, vasoconstriction, and thrombotic occlusion of the pulmonary arteries