Platelet function and prostaglandins in patients with peripheral vascular disease treated with calcium dobesilate

In a double-blind placebo controlled study, 25 male patients (age range: 48-67 years) suffering from peripheral vascular disease were treated daily for 4 weeks with either 2 g of calcium dobesilate (n = 13) or placebo (n = 12). Different platelet and prostaglandin parameters were examined before and at the end of therapy. The number of circulating endothelial cells decreased significantly (4.9 +/- 2.9 to 2.0 +/- 1.9; p less than 0.0004). In addition, a decrease in serum TXB2 was noted (p less than 0.0001), but no significant change in plasma TXB2. The fibrinogen half-life was shortened (p less than 0.0001) and the platelet half-life was prolonged (p less than 0.04). The level of beta TG was decreased (p less than 0.006), but PF4 was unchanged. No alteration in the conversion of exogenous 14C-arachidonic acid by platelets to eicosanoids was observed. These observations indicate that calcium dobesilate is able to exert a favourable effect on some parameters of platelet function and prostaglandin synthesis which are important in the regulation of the hemostatic process. It is suggested that these pharmacological actions might explain, at least in part, the beneficial clinical effect of the drug.