<p>When taken orally, Ticlopidine hydrochloride causes a time- and dose-dependent inhibition of both&nbsp;platelet aggregation and release of&nbsp;platelet&nbsp;granule constituents, as well as a prolongation of bleeding time. The intact drug has no significant&nbsp;in vitro&nbsp;activity at the concentrations attained&nbsp;in vivo; and, although&nbsp;analysis&nbsp;of&nbsp;urine&nbsp;and&nbsp;plasma&nbsp;indicates at least 20 metabolites, no metabolite which accounts for the activity of ticlopidine has been isolated.<br />
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Ticlopidine hydrochloride, after oral ingestion, interferes with platelet&nbsp;membrane&nbsp;function by inhibiting ADP-induced platelet-fibrinogen binding and subsequent platelet-platelet interactions. The effect on platelet function is irreversible for the life of the platelet, as shown both by persistent inhibition of&nbsp;fibrinogen&nbsp;binding after washing platelets ex vivo and by inhibition of platelet aggregation after resuspension of platelets in buffered medium.</p>