Use of prostacyclin and its analogues in the treatment of cardiovascular disease.

Prostacyclin is found in all body tissues and body fluids, and is the major metabolite of arachidonic acid in the vasculature. It is a potent vasodilator that affects both the systemic and pulmonary circulations. Prostacyclin also prevents vascular smooth muscle proliferation and inhibits platelet adhesion and aggregation. These features have made it a very attractive substance for treatment of many different cardiovascular diseases. Epoprostenol, a synthetic prostacyclin, is currently available in parenteral form for the treatment of primary pulmonary hypertension, and has been shown to be a valuable palliative therapy. The drug appears to have limited effectiveness for treating patients with congestive heart failure and coronary artery disease, but has shown some utility in patients with peripheral vascular disease, including Raynaud's phenomenon. Analogues of prostacyclin are now in clinical trials and include iloprost, a stable analogue that has been used intravenously to treat patients with peripheral vascular disease. Other parenteral formulations under investigation include taprostene, ciprostene, and UT-15. Beraprost and cicaprost, are two prostacyclin analogues that can be used in oral form, are being studied in clinical trials.