Antiplatelet Therapy Using Cilostazol, a Specific PDE3 Inhibitor

Introduction Cilostazol, 6- 4-( l-cyclohexy l-IH-tetrazol-5yl ) butoxy -3, 4-dihydro-2 (1H)-quinolinone, is an antiplatelet/ antithrombotic agent that has been used since 1988 in several countries, including Japan, for treatment of chronic peripheral arterial occlusion. Cilostazol was also approved by the United States Food and Drug Administration (FDA) in 1999 for the treatment of intermittent claudication. Cilostazol not only inhibits platelet activation but also increases vasodilation.1,2 In addition, it has been also shown to inhibit vascular smooth muscle cell proliferation.3 These properties of cilostazol may also improve peripheral blood flow. The mechanism of these effects is mediated through elevated cyclic adenosine monophosphate (AMP), brought about by inhibition of cyclic nucleotide phosphodiesterase (PDE3) activity.4 In this chapter, the pharmacological properties, as well as the clinical efficacy of cilostazol, are briefly discussed.