Cilostazol (cilostazol)

Cilostazol, a quinolinone-derivative selective phosphodiesterase (PDE) inhibitor, is a platelet-aggregation inhibitor and arterial vasodilator.

Cilostazol, a quinolinone-derivative selective phosphodiesterase (PDE) inhibitor, is a platelet-aggregation inhibitor and arterial vasodilator. Although the mechanism of action of cilostazol has not been fully elucidated, the drug appears to inhibit activation of cellular PDE type III (PDE III), resulting in suppressed degradation, and thus increased concentrations, of cyclic adenosine-3',5'-monophosphate (cAMP) in platelets and blood vessels. Increased cAMP concentrations are thought to result in arterial vasodilation and inhibition of platelet aggregation.

In animal studies, cilostazol appears to produce a nonhomogeneous dilation of arteries, with greater dilation in femoral arteries than in vertebral, carotid, or superior mesenteric arteries; the drug does not appear to produce vasodilation of renal arteries. Cilostazol reversibly inhibits platelet aggregation induced by a wide range of stimuli, including thrombin, adenosine diphosphate (ADP), collagen, arachidonic acid, epinephrine, and shear stress. Limited in vitro data suggest that cilostazol also may inhibit smooth muscle cell proliferation.

Cilostazol has been shown to produce favorable alterations in concentrations of certain lipoproteins. In a randomized, placebo-controlled study, treatment with the drug was associated with a 15% reduction in plasma triglycerides and a 10% increase in high-density lipoprotein (HDL)-cholesterol concentrations; the drug did not affect plasma concentrations of total cholesterol, low-density lipoprotein (LDL)-cholesterol, or lipoprotein(a) (Lp(a)). Studies in animals indicate that cilostazol may increase heart rate, myocardial contractility, coronary blood flow, and ventricular automaticity; as with other positive inotropic agents, including PDE III inhibitors, cardiovascular lesions have been noted in dogs during repeated oral dosing with cilostazol.

Absorption of cilostazol appears to be increased when the drug is administered with a high-fat meal. Following oral administration of a single 100-mg dose of cilostazol with a high-fat meal, peak plasma cilostazol concentrations and area under the plasma concentration-time curve (AUC) increased by approximately 90 and 25%, respectively. Because increased plasma cilostazol concentrations may be associated with a higher incidence of adverse effects, the manufacturer recommends that the drug be taken on an empty stomach. (See Dosage and Administration: Administration.) Peak pharmacodynamic effects (antiplatelet activity, heart-rate increase, decrease in diastolic blood pressure) of cilostazol occur within approximately 6 hours.

In intermittent claudication, symptomatic relief may occur within 2-4 weeks of initial therapy; up to 12 weeks may be required to obtain optimum therapeutic effect. Cilostazol is extensively metabolized in the liver via the cytochrome P-450 (CYP) enzyme system, mainly by the isoenzyme CYP 3A4 and, to a lesser extent, CYP2C19. Two active metabolites, including one that accounts for at least 50% of the pharmacologic activity (PDE inhibition) of the drug, have been identified.

Approximately 74 and 20% of an oral dose of cilostazol is excreted in urine and feces, respectively, as active and inactive metabolites.

USES: Cilostazol is used to improve the symptoms of a certain blood flow problem in the legs (intermittent claudication). Cilostazol can decrease the muscle pain/cramps that occur during exercise/walking. Claudication pain is caused by too little oxygen getting to the muscles.

Cilostazol can increase blood flow and the amount of oxygen that gets to the muscles. Cilostazol is an antiplatelet drug and a vasodilator. It works by stopping blood cells called platelets from sticking together and prevents them from forming harmful clots.

It also widens blood vessels in the legs. Cilostazol helps the blood to move more easily and keeps blood flowing smoothly in your body.

Generic name: cilostazol
Pronunciation: (sye-LOE-sta-zol)

The following indications are listed for Cilostazol:

• Intermittent Claudication

Also known as: Angina Cruris, Charcot's Syndrome, Myasthenia Angiosclerotica.

No ICD codes are available for this drug.