The Effect of ICI 55,897 and Clofibrate on Platelet Function and Other Tests Abnormal in Atherosclerosis

Abstract

SummaryThere is considerable evidence that the quantity or quality of plasma lipids influences platelet function tests, and clofibrate reduces high plasma lipids and alters some platelet tests. Clofibrate was accordingly given to patients with vascular disease who were at risk of thrombosis. The heparin thrombin clotting time (HTCT), initially short and thus possibly reflecting increased activation, was regularly returned to normal after about a month’s delay. The fibrinogen was also normalized but the initially abnormal anti-thrombic activity became more abnormal. ICI 55,897, an analogue of clofibrate, also normalized the HTCT and the fibrinogen and had no adverse effect on the anti-thrombin levels. This compound has no effect on plasma lipids. If it can be shown that the correction of abnormal tests conveys clinical benefit these findings suggest that ICI 55,897 might clinically be more beneficial than clofibrate. However, direct comparison of clofibrate and ICI 55,897 suggests that clofibrate is more effective in normalizing the HTCT. The mechanisms underlying these drug-induced changes are unknown but they cannot be directly related to lipid changes.

Determination of ticlopidine in human plasma by capillary gas chromatography with ion trap detection

“…Among agents that inhibit platelet function, ticlopidine shows a wide spectrum of antiplatelet activity [2]. Ticlopidine is superior to aspirin and dipyridamole as antithrombotic agent towards different kinds of experimental thrombosis [3,4].…”