<prompt> All are ADP inhibitors except -TiclopidineTirofibanClopidogrelPrasugel  <response>: Ans. is b i.e., Tirofiban Antiplatelet drugs Antiplatelet drugs act by inhibiting one or other proaggregative mediators or mechanism. Aspirin in low doses - inhibits synthesis of TXA2 by inhibiting the enzyme cycloxygenase So that immediate precursor prostaglandins of TXA2 are not synthesized. Ticlopidine, clopidogrel, Prasugrel - they block ADP mediated platelet activation by irreversible antagonism of P2 Yl2 receptor on ADP. Can grelor and ticagrelor - are reversible antagonist of ADP P2 Y12, in contrast to ticlopidine, which is irreversible antagonist. Dipyridamol - Inhibits phosphodiesterase - cAMP, It also blocks uptake of adenosine. Epoprostinol - A prostacyclin - cAMP. Abciximab, eptifibatide, tirofiban, Lamifiban - GPIIbIIIa inhibitors. Cilastazole is a phosphodiesterase-3 inhibitors and result in elevated cAMP levels. It reduces platelet aggregation and also passess peripheral vasodilatory action. It can be used for the treatment of intermittent claudication. 