Clinical Evaluation Of Ticlopidine In The Inhibition Of Platelet Function - A Multiclinic Double Blind Study In Comparison With Aspirin

Clinical effect of ticlopidine, a new inhibitor of platelet aggregation, at a daily dose of 300 mg was compared with that of aspirin at its daily dose of 500 mg by means of double blind assay. The suppression of platelet aggregations induced by ADP, collagen and epinephrine was compared among platelet samples obtained from 38 cases with thrombotic tendency or at enhanced platelet functions.

The inhibitory efficacy of ticlopidine on platelet aggregations induced by collagen or epinephrine was found as potent as that of aspirin in their overall judgement, but the ticlopidine inhibition on the ADP aggregation was apparently more potent than aspirin. The maximum aggregation rate was significantly decreased and the frequency of the second aggregation pattern was more remarkably minimized in the ticlopidine-treated group than the aspirin-group. The maximum aggregation rates induced by collagen or epinephrine were significantly decreased in both of ticlopidine- and aspirin-groups to the same extent.

Blood filtration velocity through Nuclepore filter of 5μm pore size was significantly enhanced in the ticlopidine- group but no change found in the aspirin-group. Other coagulation parameters and laboratory data were not changed in both groups, except bleeding and prothrombin times which were slightly prolonged in the aspirin-group.

From the results mentioned above, it was expected that ticlopidine might exert superior clinical effect to aspirin on thrombotic diseases and microcirculatory disorders