Cilostazol, industrially sold as Pletal, is a quinolone derivative antiplatelet drug and a vasodilator used to prevent platelet aggregation, specifically treating symptoms of intermittent claudication caused by peripheral artery disease as well as preventing strokes in Homo sapiens. It acts on blood cells called platelets and on the vasculature by inhibiting phosphodiesterase 3 activity which causes these platelets to stop from sticking together, preventing formation of harmful clots. Cilostazol helps the blood to move more easily and keeps blood flowing smoothly in your body. Cilostazol is ingested orally, and it enters the liver (not shown here), where it is metabolized into active metabolites that inhibit the action of cAMP-specific 3',5'-cyclic phosphodiesterase 4D which converts cyclic adenosine monophosphate (cAMP) to adenosine monophosphate (AMP) in platelets. Inhibition of PDE3 causes a build-up of cAMP which subsequently leads to increased concentrations of the active form of protein kinase A (PKA). PKA then converts vasodilator-stimulated phosphoprotein (VASP) into phosphorylated vasodilator-stimulated phosphoprotein (VASP-P) which in turn is known to prevent aggregation of platelets, by inhibiting their adhesion to collagen, as well as decreasing the amount of calcium within the cytosol, preventing granule release, which then prevents activation of other platelets. Usage of cilostazol relieves symptoms like claudication(cramps) and the intermittent pain it causes. Common side effects of cilostazol are headache, diarrhea, vomiting, abnormal stools, dizziness, weakness, fast or pounding heartbeats, palpitations, swelling (edema), leg cramps, numbness or tingling, joint pain, cough, runny or stuffy nose, infections.

Cilostazol Pathway (new) References