Ultrastructural and functional studies on human platelets incubated with diclofenac sodium (Voltaren).

The in vitro effect of diclofenac sodium (Voltaren) on the ultrastructure of healthy donors' platelets was examined and compared with those induced by aspirin (ASA). In distinction to ASA, which causes loss of platelet pseudopodia, Voltaren induced an increase and marked elongation of these pseudopodia. The implication of this finding in the explanation of the decreased platelet aggregation caused by the drug is discussed. Voltaren increased the phagocytotic activity of the individual platelet, although the overall ability of the cells to phagocytize latex particles was not markedly increased. Platelets incubated with Voltaren showed a decrease in their total protein synthesizing capacity. Voltaren did not exert any effect on the internal ultrastructure, platelet factor 3, and calcium content of the incubated platelets.