Inhalation of the stable prostacyclin analogue iloprost is being studied for treatment of pulmonary hypertension. The selective phosphodiesterase-5 inhibitor sildenafil has been reported to cause pulmonary vasodilatation.
Department of Internal Medicine, University Hospital, Justus-Liebig-University, Klinikstrasse 36, 35392 Giessen, Germany. ardeschir.ghofrani@innere.med.uni-giessen.de