The pharmacological effects of cicaprost, an oral prostacyclin analogue, in patients with Raynaud's syndrome secondary to systemic sclerosis--a preliminary study.

Prostacyclin (PGI2) and its analogues are useful treatments for patients with secondary Raynaud's syndrome (RS). However, they have to be given intravenously, causing inconvenience to patients. Cicaprost is an orally available analogue of PGI2 and has been shown to inhibit platelet aggregation in both in vitro and animal studies. We recently investigated the effects of cicaprost on whole blood platelet aggregation, red cell deformability, white cell function (polymorphonuclear cell aggregation, elastase release and free radical activity) and plasma fibrinolysis in 14 patients with systemic sclerosis (SSc) and secondary RS. Patients received cicaprost (2.5 micrograms or 5 micrograms t.i.d.) or matching placebo tablets orally for 10 days. Blood samples were taken at baseline and 2 hours after administration of the last treatment for the above mentioned assays. No changes were observed in any of the cellular elements and parameters measured in the 3 groups of patients studied. Our study suggests that cicaprost, at doses up to 5 micrograms t.i.d., fails to modify the blood coagulation elements and factors in patients with RS secondary to SSc. Further studies using higher doses and longer study periods are planned.