Prostacyclin is a substance produced by endothelial cells that induces vaso
dilation and inhibition of platelet aggregation and of vascular cell migrat
ion and proliferation. A dysregulation of the prostacyclin metabolic pathwa
ys has been shown in patients with pulmonary arterial hypertension. The cli
nical use of prostacyclin has been made possible by the synthesis of stable
analogues that possesses different pharmacokinetic properties but share si
milar pharmacodynamic effects. The greatest experience has been collected w
ith intravenous epoprostenol while other compounds like subcutaneous UT-15,
inhaled iloprost and oral beraprost are currently in different stages of c
linical development. Although favorable results have been reported for each
compound, different benefit-to-side effects profiles characterize the vari
ous modalities of the administration.