Ticlopidine is an inhibitor of platelets function in vivo. It inhibits platelets aggregation induced by ADP. Its mode of action has not been defined, but it appears that metabolites of ticlopidine are antagonists of the platelet ADP receptor. Inhibition of platelet aggregation is delayed until 24 to 48 hours after drug administration, achieving maximum after 3 to 5 days of treatment. Recovery of platelet function occurs from 4 to 14 days after discontinuation of ticlopidine. It is potent antiplatelet factor, possible to use (among other in view of low price) in secondary prevention of cardiovascular diseases as alternative drug, especially in prevention of thrombosis during coronary stent placement.. Use of ticlopidine is limited by numerous side effects forcing quite often to discontinuation of therapy. It seems, that better safety profile, and it probably larger efficiency shows different derivative of thienopiridyn--clopidogrel.