All are ADP inhibitors except -

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 - GPIIb/IIIa 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.