Cilostazol is a lactam that is 3,4-dihydroquinolin-2(1H)-one in which the hydrogen at position 6 is substituted by a 4-(1-cyclohexyl-1H-tetrazol-5-yl)butoxy group. It has a role as a bronchodilator agent, a vasodilator agent, a fibrin modulating drug, a platelet aggregation inhibitor, a neuroprotective agent, an anticoagulant and an EC 3.1.4.17 (3′,5′-cyclic-nucleotide phosphodiesterase) inhibitor. It is a member of tetrazoles and a lactam.