[Pharmacological and clinical properties of beraprost sodium, orally active prostacyclin analogue]

Prostacyclin is an endogeneous eicosanoid synthesized by vascular endothelial cells, and has potent inhibitory effects on platelet adhesion/aggregation and vasoconstriction. However, its therapeutic use is restricted by its extremely short half-life. Beraprost sodium (beraprost) is the first orally active prostacyclin analogue developed by TORAY Industries, Inc. Beraprost possesses a phenol moiety instead of the exo-enol ether moiety, which is the cause of the instability of prostacyclin, and has a modified omega-side chain that contributes to dissociating antiplatelet action from adverse reactions. In 1992, beraprost was approved as a drug for chronic arterial occlusion. Beraprost is now widely used clinically as "Dorner" or "Procylin". The indication for "primary pulmonary hypertension" was also approved in 1999. Recently in Europe, a placebo controlled trial named "Beraprost et Claudication Intermittent-2 (BERCI-2)" was performed, and it was reported that beraprost improved the walking distances of the patients. Beraprost has a variety of biological activities such as antiplatelet effects, vasodilation effects, antiproliferative effects on vascular smooth muscle cells, cytoprotective effects on endothelial cells and inhibitory effects on the production of inflammatory cytokines. On the basis of basic and clinical research, it has been suggested that beraprost is also effective for many intractable diseases. We expect that the relationship between reduced prostacyclin level and these diseases would be clarified and the beneficial effects of beraprost would be demonstrated by controlled clinical trials in the future.