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"Cilostazol: Pharmacokinetics, Clinical Effects, Interactions, and Adverse Reactions", Exams of Marketing

Information on the effects of cilostazol on circulating plasma lipids, its pharmacokinetics in healthy subjects and those with intermittent claudication, protein binding, hepatic and renal impairment, drug interactions with aspirin, quinidine, and cytochrome P-450 isoenzymes, and clinical studies on improving walking distance in patients with intermittent claudication. It also includes information on contraindications, warnings, and adverse reactions.

What you will learn

  • What drug interactions have been identified with cilostazol?
  • What are the effects of cilostazol on circulating plasma lipids?
  • How does cilostazol affect protein binding?

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2021/2022

Uploaded on 09/12/2022

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CILOSTAZOL - cilos tazol tablet
STAT RX USA LLC
----------
Cilos taz ol Tablets
50 m g and 100 mg
Rx only
CONTRAINDICATION
Cilos tazol and several of its metabolites are inhibitor s of phospho die sterase III. Several drug s
with this pharmaco lo gic effec t have c aused decre ased s urvival c ompared to placebo in patients
with class III-IV co ngestive heart failur e. Cilos tazol is contraindicated in patients with conge stive
heart failure of any se verity.
DESCRIPT ION
Cilos tazol is a quinolinone de rivative that inhibits c ellular phosphodiesterase (more specific for
phos phodie steras e III). The empirical fo rmula of c ilos tazol is C H N O , and its molecular weight
is 369 .4 6. Cilostazol is 6-[4-(1-cyc lo he xyl- 1H-tetrazol-5-yl)butoxy]-3,4 -dihydro-2(1H)-quinolinone,
CAS- 73963-72-1. The s tructural formula is:
Cilos tazol occ urs as white to o ff-white crystals o r as a c rys talline powde r that is slig htly soluble in
methanol and ethanol, and is practic ally inso luble in water, 0.1 N HCl, and 0.1 N NaOH.
Cilos tazol tablets fo r or al administration are available as 50 mg or 10 0 mg round, white debo sse d
tablets. Each tablet, in addition to the active ingredie nt, contains the follo wi ng inactive ingre die nts:
carboxymethylc ellulose calcium, corn starc h, hypromellose , magnesi um stearate and microcrystalline
ce llulo se.
CLINICAL PHARMACOLOGY
Mec hanis m of Action:
The mechanism of the ef fe cts o f c il ostazol on the symptoms of intermittent claudicatio n is not fully
understoo d. Cilo stazol and se veral of its metabolites are cyc li c AMP (cAMP) phospho die sterase III
inhibitors (PDE III inhibito rs ), inhibiting phospho die sterase activity and suppre ssing cAMP degradation
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CILOSTAZOL - cilos tazol tablet STAT RX USA LLC


Cilos tazol Tablets 50 mg and 100 mg Rx only CONTRAINDICATION Cilostazol and several of its metabolites are inhibitors of phosphodiesterase III. Several drugs with this pharmacologic effect have caused decreased survival compared to placebo in patients with class III-IV congestive heart failure. Cilostazol is contraindicated in patients with congestive heart failure of any severity. DESCRIPTION Cilostazol is a quinolinone derivative that inhibits cellular phosphodiesterase (more specific for phosphodiesterase III). The empirical formula of cilostazol is C H N O , and its molecular weight is 369.46. Cilostazol is 6-[4-(1-cyclohexyl-1 H -tetrazol-5-yl)butoxy]-3,4-dihydro-2(1 H )-quinolinone, CAS-73963-72-1. The structural formula is: Cilostazol occurs as white to off-white crystals or as a crystalline powder that is slightly soluble in methanol and ethanol, and is practically insoluble in water, 0.1 N HCl, and 0.1 N NaOH. Cilostazol tablets for oral administration are available as 50 mg or 100 mg round, white debossed tablets. Each tablet, in addition to the active ingredient, contains the following inactive ingredients: carboxymethylcellulose calcium, corn starch, hypromellose, magnesium stearate and microcrystalline cellulose. CLINICAL PHARMACOLOGY Mechanis m of Action: The mechanism of the effects of cilostazol on the symptoms of intermittent claudication is not fully understood. Cilostazol and several of its metabolites are cyclic AMP (cAMP) phosphodiesterase III inhibitors (PDE III inhibitors), inhibiting phosphodiesterase activity and suppressing cAMP degradation 20 27 5 2

with a resultant increase in cAMP in platelet and blood vessels, leading to inhibition of platelet aggregation and vasodilation, respectively. Cilostazol reversibly inhibits platelet aggregation induced by a variety of stimuli, including thrombin, ADP, collagen, arachidonic acid, epinephrine, and shear stress. Effects on circulating plasma lipids have been examined in patients taking cilostazol. After 12 weeks, as compared to placebo, cilostazol 100 mg b.i.d. produced a reduction in triglycerides of 29.3 mg/dL (15%) and an increase in HDL- cholesterol of 4.0 mg/dL ( 10%). Cardiovascular Effects: Cilostazol affects both vascular beds and cardiovascular function. It produces non-homogeneous dilation of vascular beds, with greater dilation in femoral beds than in vertebral, carotid, or superior mesenteric arteries. Renal arteries were not responsive to the effects of cilostazol. In dogs or cynomolgous monkeys, cilostazol increased heart rate, myocardial contractile force, and coronary blood flow as well as ventricular automaticity, as would be expected for a PDE III inhibitor. Left ventricular contractility was increased at doses required to inhibit platelet aggregation. A-V conduction was accelerated. In humans, heart rate increased in a dose-proportional manner by a mean of 5.1 and 7.4 beats per minute in patients treated with 50 and 100 mg b.i.d., respectively. In 264 patients evaluated with Holter monitors, numerically more cilostazol-treated patients had increases in ventricular premature beats and non-sustained ventricular tachycardia events than did placebo-treated patients; the increases were not dose-related. Pharmacokinetics : Cilostazol is absorbed after oral administration. A high fat meal increases absorption, with an approximately 90% increase in C and a 25% increase in AUC. Absolute bioavailability is not known. Cilostazol is extensively metabolized by hepatic cytochrome P-450 enzymes, mainly 3A4, and, to a lesser extent, 2C19, with metabolites largely excreted in urine. Two metabolites are active, with one metabolite appearing to account for at least 50% of the pharmacologic (PDE III inhibition) activity after administration of cilostazol. Pharmacokinetics are approximately dose proportional. Cilostazol and its active metabolites have apparent elimination half-lives of about 11-13 hours. Cilostazol and its active metabolites accumulate about 2-fold with chronic administration and reach steady state blood levels within a few days. The pharmacokinetics of cilostazol and its two major active metabolites were similar in healthy normal subjects and patients with intermittent claudication due to peripheral arterial disease (PAD). The mean ± SEM plasma concentration-time profile at steady state after multiple dosing of cilostazol 100 mg b.i.d. is shown below: max

Smokers: Population pharmacokinetic analysis suggests that smoking decreased cilostazol exposure by about 20%. Hepatic Impairment: The pharmacokinetics of cilostazol and its metabolites were similar in subjects with mild hepatic disease as compared to healthy subjects. Patients with moderate or severe hepatic impairment have not been studied. Renal Impairment: The total pharmacologic activity of cilostazol and its metabolites was similar in subjects with mild to moderate renal impairment and in normal subjects. Severe renal impairment increases metabolite levels and alters protein binding of the parent and metabolites. The expected pharmacologic activity, however, based on plasma concentrations and relative PDE III inhibiting potency of parent drug and metabolites, appeared little changed. Patients on dialysis have not been studied, but, it is unlikely that cilostazol can be removed efficiently by dialysis because of its high protein binding (95%-98%). Pharmacokinetic and Pharmacodynamic Drug-Drug Interactions: Cilostazol could have pharmacodynamic interactions with other inhibitors of platelet function and pharmacokinetic interactions because of effects of other drugs on its metabolism by CYP3A4 or CYP2C19. A reduced dose of cilostazol should be considered when taken concomitantly with CYP3A or CYP2C19 inhibitors. Cilostazol does not appear to inhibit CYP3A4 (see Pharmacokinetic and Pharmacodynamic Drug-Drug Interactions, Lovastatin). Aspirin: Short-term (≤ 4 days) coadministration of aspirin with cilostazol increased the inhibition of ADP-induced ex vivo platelet aggregation by 22% - 37% when compared to either aspirin or cilostazol alone. Short-term (≤ 4 days) coadministration of aspirin with cilostazol increased the inhibition of arachidonic acid-induced ex vivo platelet aggregation by 20% compared to cilostazol alone and by 48% compared to aspirin alone. However, short-term coadministration of aspirin with cilostazol had no clinically significant impact on PT, aPTT, or bleeding time compared to aspirin alone. Effects of long- term coadministration in the general population are unknown. In eight randomized, placebo-controlled, double-blind clinical trials, aspirin was coadministered with cilostazol to 201 patients. The most frequent doses and mean durations of aspirin therapy were 75-81 mg daily for 137 days (107 patients) and 325 mg daily for 54 days (85 patients). There was no apparent increase in incidence of hemorrhagic adverse effects in patients taking cilostazol and aspirin compared to patients taking placebo and equivalent doses of aspirin. Warfarin: The cytochrome P-450 isoenzymes involved in the metabolism of R-warfarin are CYP3A4, CYP1A2, and CYP2C19, and in the metabolism of S-warfarin, CYP2C9. Cilostazol did not inhibit either the metabolism or the pharmacologic effects (PT, aPTT, bleeding time, or platelet aggregation) of R- and S-warfarin after a single 25-mg dose of warfarin. The effect of concomitant multiple dosing of warfarin and cilostazol on the pharmacokinetics and pharmacodynamics of both drugs is unknown. Clopidogrel: Multiple doses of clopidogrel do not significantly increase steady state plasma concentrations of cilostazol. Inhibitors of CYP3A Strong Inhibitors of CYP3A4 : A priming dose of ketoconazole 400 mg (a strong inhibitor of CYP3A4), was given one day prior to coadministration of single doses of ketoconazole 400 mg and cilostazol 100 mg. This regimen increased cilostazol C by 94% and AUC by 117%. Other strong inhibitors of CYP3A4, such as itraconazole, fluconazole, miconazole, fluvoxamine, fluoxetine, nefazodone, and sertraline, would be expected to have a similar effect (see DOSAGE AND ADMINISTRATION). Moderate Inhibitors of CYP3A4 :

  1. Erythromycin and other macrolide antibiotics: Erythromycin is a moderately strong inhibitor of CYP3A4. Coadministration of erythromycin 500 mg q 8h with a single dose of cilostazol 100 mg increased cilostazol C by 47% and AUC by 73%. Inhibition of cilostazol metabolism by max max

erythromycin increased the AUC of 4´-trans-hydroxy-cilostazol by 141%. Other macrolide antibiotics (e.g., clarithromycin), but not all (e.g., azithromycin), would be expected to have a similar effect (see DOSAGE AND ADMINISTRATION).

  1. Diltiazem: Diltiazem 180 mg decreased the clearance of cilostazol by 30%. Cilostazol C increased 30% and AUC increased 40% (see DOSAGE AND ADMINISTRATION).
  2. Grapefruit Juice: Grapefruit juice increased the C of cilostazol by 50%, but had no effect on AUC. Inhibitors of CYP2C19: Omeprazole: Coadministration of omeprazole did not significantly affect the metabolism of cilostazol, but the systemic exposure of 3,4-dehydro-cilostazol was increased by 69%, probably the result of omeprazole's potent inhibition of CYP2C19 (see DOSAGE AND ADMINISTRATION). Quinidine: Concomitant administration of quinidine with a single dose of cilostazol 100 mg did not alter cilostazol pharmacokinetics. Lovastatin: The concomitant administration of lovastatin with cilostazol decreases cilostazol C and AUC by 15%. There is also a decrease, although nonsignificant, in cilostazol metabolite concentrations. Coadministration of cilostazol with lovastatin increases lovastatin and β-hydroxi lovastatin AUC approximately 70%. This is most likely clinically insignificant. CLINICAL STUDIES: The ability of cilostazol to improve walking distance in patients with stable intermittent claudication was studied in eight large, randomized, placebo-controlled, double-blind trials of 12 to 24 weeks’ duration using dosages of 50 mg b.i.d. (n=303), 100 mg b.i.d. (n=998), and placebo (n=973). Efficacy was determined primarily by the change in maximal walking distance from baseline (compared to change on placebo) on one of several standardized exercise treadmill tests. Compared to patients treated with placebo, patients treated with cilostazol tablets 50 or 100 mg b.i.d. experienced statistically significant improvements in walking distances both for the distance before the onset of claudication pain and the distance before exercise-limiting symptoms supervened (maximal walking distance). The effect of cilostazol on walking distance was seen as early as the first on-therapy observation point of two or four weeks. The following figure depicts the percent mean improvement in maximal walking distance at study end for each of the eight studies. max max max ss, max τ

CONTRAINDICATIONS

Cilos tazol and s everal of its metabolites are inhibitors of phos phodies teras e III. Several drugs with this pharmacologic effect have caus ed decreas ed s urvival compared to placebo in patients with clas s III-IV conges tive heart failure. Cilos tazol tablets are contraindicated in patients with conges tive heart failure of any s everity. Cilos tazol tablets are contraindicated in patients with haemos tatic dis orders or active pathologic bleeding, s uch as bleeding peptic ulcer and intracranial bleeding. Cilos tazol tablets inhibit platelet aggregation in a revers ible manner. Cilos tazol tablets are contraindicated in patients with known or s us pected hypers ens itivity to any of its components. PRECAUTIONS Hematologic adverse reactions: Rare cases have been reported of thrombocytopenia or leucopenia progressing to agranulocytosis when cilostazol was not immediately discontinued. The agranulocytosis, however, was reversible on discontinuation of Cilostazol. Use with Clopidogrel: There is limited information with respect to the efficacy or safety of the concurrent use of cilostazol and clopidogrel, a platelet-aggregation inhibiting drug indicated for use in patients with peripheral arterial disease. Although it cannot be determined whether there was an additive effect on bleeding times during concomitant administration with cilostazol and clopidogrel, caution is advised for checking bleeding times during coadministration. Information for Patients: Please refer to the patient package insert. Patients should be advised: to read the patient package insert for cilostazol carefully before starting therapy and to reread it each time therapy is renewed in case the information has changed. to take cilostazol at least one-half hour before or two hours after food. that the beneficial effects of cilostazol on the symptoms of intermittent claudication may not be immediate. Although the patient may experience benefit in 2 to 4 weeks after initiation of therapy, treatment for up to 12 weeks may be required before a beneficial effect is experienced. Hepatic Impairment: Patients with moderate or severe hepatic impairment have not been studied in clinical trials. Special caution is advised when cilostazol is used in such patients. Renal Impairment : Patients on dialysis have not been studied, but, it is unlikely that cilostazol can be removed efficiently by dialysis because of its high protein binding (95-98%). Special caution is advised when cilostazol is used in patients with severe renal impairment; estimated creatinine clearence, <25 ml/min. Drug Interactions : Since cilostazol is extensively metabolized by cytochrome P-450 isoenzymes, caution should be exercised when cilostazol is coadministered with inhibitors of CYP3A4 such as ketoconazole and erythromycin or inhibitors of CYP2C19 such as omeprazole. Pharmacokinetic studies have demonstrated that omeprazole and erythromycin significantly increased the systemic exposure of cilostazol and/or its major metabolites. Population pharmacokinetic studies showed higher

concentrations of cilostazol among patients concurrently treated with diltiazem, an inhibitor of CYP3A (see CLINICAL PHARMACOLOGY, Pharmacokinetic and Pharmacodynamic Drug-Drug Interactions ). Cilostazol does not, however, appear to cause increased blood levels of drugs metabolized by CYP3A4, as it had no effect on lovastatin, a drug with metabolism very sensitive to CYP3A4 inhibition. Use with other anitplatelet agents: Cilostazol inhibits platelet aggregation but in a reversible manner. Caution is advised in patients at risk of bleeding from surgery or pathologic processes. Platelet aggregability returns to normal within 96 hours of stopping cilostazol. Caution is advised in patients receiving both cilostazol and any other antiplatelet agent, or in patients with thrombocytopenia. Cardiovascular Toxicity: Repeated oral administration of cilostazol to dogs (30 or more mg/kg/day for 52 weeks, 150 or more mg/kg/day for 13 weeks, and 450 mg/kg/day for 2 weeks), produced cardiovascular lesions that included endocardial hemorrhage, hemosiderin deposition and fibrosis in the left ventricle, hemorrhage in the right atrial wall, hemorrhage and necrosis of the smooth muscle in the wall of the coronary artery, intimal thickening of the coronary artery, and coronary arteritis and periarteritis. At the lowest dose associated with cardiovascular lesions in the 52-week study, systemic exposure (AUC) to unbound cilostazol was less than that seen in humans at the maximum recommended human dose (MRHD) of 100 mg b.i.d. Similar lesions have been reported in dogs following the administration of other positive inotropic agents (including PDE III inhibitors) and/or vasodilating agents. No cardiovascular lesions were seen in rats following 5 or 13 weeks of administration of cilostazol at doses up to 1500 mg/kg/day. At this dose, systemic exposures (AUCs) to unbound cilostazol were only about 1.5 and 5 times (male and female rats, respectively) the exposure seen in humans at the MRHD. Cardiovascular lesions were also not seen in rats following 52 weeks of administration of cilostazol at doses up to 150 mg/kg/day. At this dose, systemic exposures (AUCs) to unbound cilostazol were about 0.5 and 5 times (male and female rats, respectively) the exposure in humans at the MRHD. In female rats, cilostazol AUCs were similar at 150 and 1500 mg/kg/day. Cardiovascular lesions were also not observed in monkeys after oral administration of cilostazol for 13 weeks at doses up to 1800 mg/kg/day. While this dose of cilostazol produced pharmacologic effects in monkeys, plasma cilostazol levels were less than those seen in humans given the MRHD, and those seen in dogs given doses associated with cardiovascular lesions. Carcinogenesis, Mutagenesis, Impairment of Fertility: Dietary administration of cilostazol to male and female rats and mice for up to 104 weeks, at doses up to 500 mg/kg/day in rats and 1000 mg/kg/day in mice, revealed no evidence of carcinogenic potential. The maximum doses administered in both rat and mouse studies were, on a systemic exposure basis, less than the human exposure at the MRHD of the drug. Cilostazol tested negative in bacterial gene mutation, bacterial DNA repair, mammalian cell gene mutation, and mouse in vivo bone marrow chromosomal aberration assays. It was, however, associated with a significant increase in chromosomal aberrations in the in vitro Chinese Hamster Ovary Cell assay. Cilostazol did not affect fertility or mating performance of male and female rats at doses as high as 1000 mg/kg/day. At this dose, systemic exposures (AUCs) to unbound cilostazol were less than 1. times in males, and about 5 times in females, the exposure in humans at the MRHD. Pregnancy: Pregnancy Category C: In a rat developmental toxicity study, oral administration of 1000 mg cilostazol/kg/day was associated with decreased fetal weights, and increased incidences of cardiovascular, renal, and skeletal anomalies (ventricular septal, aortic arch, and subclavian artery abnormalities, renal pelvic dilation, 14 rib, and retarded ossification). At this dose, systemic exposure to unbound cilostazol in nonpregnant rats was about 5 times the exposure in humans given the MRHD. Increased incidences of ventricular septal defect and retarded ossification were also noted at 150 mg/kg/day (5 times the MRHD on a systemic exposure basis). In a rabbit developmental toxicity study, an increased incidence of retardation of ossification of the sternum was seen at doses as low as 150 mg/kg/day. In nonpregnant rabbits given 150 mg/kg/day, exposure to unbound cilostazol was th

Palpitation 5 10 1 Tachycardia 4 4 1 DIGESTIVE Abnormal stools 12 15 4 Diarrhea 12 19 7 Dyspepsia 6 6 4 Flatulence 2 3 2 Nausea 6 7 6 METABOLIC & NUTRITIONAL Peripheral edema 9 7 4 MUSCULO-SKELETAL Myalgia 2 3 2 NERVOUS Dizziness 9 10 6 Vertigo 3 1 1 RESPIRATORY Cough increased 3 4 3 Pharyngitis 7 10 7 Rhinitis 12 7 5 Less frequent adverse events (< 2%) that were experienced by patients exposed to cilostazol 50 mg b.i.d. or 100 mg b.i.d. in the eight controlled clinical trials and that occurred at a frequency in the 100 mg b.i.d. group greater than in the placebo group, regardless of suspected drug relationship, are listed below. Body As a Whole: Chills, face edema, fever, generalized edema, malaise, neck rigidity, pelvic pain, retroperitoneal hemorrhage. Cardiovascular: Atrial fibrillation, atrial flutter, cerebral infarct, cerebral ischemia, congestive heart failure, heart arrest, hemorrhage, hypotension, myocardial infarction, myocardial ischemia, nodal arrhythmia, postural hypotension, supraventricular tachycardia, syncope, varicose vein, vasodilation, ventricular extrasystoles, ventricular tachycardia. Digestive: Anorexia, cholelithiasis, colitis, duodenal ulcer, duodenitis, esophageal hemorrhage, esophagitis, increased GGT, gastritis, gastroenteritis, gum hemorrhage, hematemesis, melena, peptic ulcer, periodontal abscess, rectal hemorrhage, stomach ulcer, tongue edema. Endocrine: Diabetes mellitus. Hemic and Lymphatic: Anemia, ecchymosis, iron deficiency anemia, polycythemia, purpura. Metabolic and Nutritional: : Increased creatinine, gout, hyperlipemia, hyperuricemia. Musculoskeletal: Arthralgia, bone pain, bursitis. Nervous: Anxiety, insomnia, neuralgia. Respiratory: Asthma, epistaxis, hemoptysis, pneumonia, sinusitis. Skin and Appendages: Dry skin, furunculosis, skin hypertrophy, urticaria. Special Senses: Amblyopia, blindness, conjunctivitis, diplopia, ear pain, eye hemorrhage, retinal hemorrhage, tinnitus. Urogenital: Albuminuria, cystitis, urinary frequency, vaginal hemorrhage, vaginitis. Pos t-Marketing Experience The following adverse events have been reported spontaneously from worldwide post-marketing experience since launch of cilostazol in the US. Blood and lymphatic system disorders:

  • (^) agranulocytosis, aplastic anemia, granulocytopenia, thrombocytopenia, leukopenia, bleeding tendency

Cardiac disorders:

Gastrointestinal disorders:

General disorders and administration site conditions:

Hepatobiliary disorders:

Injury, poisoning and procedural complications:

Investigations :

Nervous system disorders:

Respiratory, thoracic and mediastinal disorders:

Skin and subcutaneous tissue disorders:

Vascular disorders:

OVERDOSAGE Information on acute overdosage with cilostazol in humans is limited. The signs and symptoms of an acute overdose can be anticipated to be those of excessive pharmacologic effect: severe headache, diarrhea, hypotension, tachycardia, and possibly cardiac arrhythmias. The patient should be carefully observed and given supportive treatment. Since cilostazol is highly protein-bound, it is unlikely that it Torsades de pointes, QTc prolongation (Torsades de pointes and QTc prolongation occurred in patients with cardiac disorders, e.g. complete atrioventricular block, cardiac failure and bradyarrythmia, when treated with cilostazol. Cilostazol was used “off label” due to its positive chronotropic action.) gastrointestinal hemorrhage pain, chest pain, hot flushes hepatic dysfunction/abnormal liver function tests, jaundice extradural hematoma and subdural hematoma blood glucose increased, blood uric acid increased, platelet count decreased, white blood cell count decreased, increase in BUN (blood urea increased), blood pressure increase intracranial hemorrhage, cerebral hemorrhage, cerebrovascular accident pulmonary hemorrhage, interstitial pneumonia hemorrhage subcutaneous, pruritus, skin eruptions including Stevens-Johnson syndrome, skin drug eruption (dermatitis medicamentosa) subacute thrombosis (These cases of subacute thrombosis occurred in patients treated with aspirin and “off label” use of cilostazol for prevention of thrombotic complication after coronary stenting.)

claudication. What is intermittent claudication? Intermittent claudication is pain in the legs that occurs with walking and disappears with rest. It occurs because narrowing or blockage of the arteries decreases blood flow to the legs. The decreased blood flow does not supply enough oxygen to the leg muscles during walking, resulting in these painful leg cramps. What treatments are available for intermittent claudication? The three main treatments available for intermittent claudication are: Exercise. Your doctor may advise an exercise program. Medication. Your doctor may prescribe a medication such as cilostazol. (See Who should not take cilostazol? ) Surgery. Your doctor may recommend a surgical procedure to bypass the blocked segment of the artery. Another procedure is called a percutaneous transluminal angioplasty. In this procedure, a catheter (a flexible tube) is inserted into the artery to reduce the blockage and improve blood flow. How does cilostazol work? The exact way that many drugs work is not well understood. Although how cilostazol works is not completely clear, its main effects are to dilate (widen) the arteries supplying blood to the legs and to decrease the ability of platelets in the blood to stick together. Platelets are particles that circulate in the blood and play a role in clotting. Cilostazol may reduce the leg pain that patients with intermittent claudication experience, allowing them to walk farther before their leg pain occurs. Improvement in symptoms may occur as soon as 2 weeks, but could take up to 12 weeks. If you have not noticed any benefit from cilostazol after 12 weeks you and your doctor may wish to discuss other forms of treatment. Sometimes blood vessel disease of the legs causes pain at rest or breakdown of skin in the leg. Cilostazol has not been shown to work in patients with these problems. Who should not take cilostazol? Patients who have conges tive heart failure (CHF) mus t not take cilos tazol. The most common symptoms of CHF are shortness of breath and swelling of the legs. However, other conditions may also cause these symptoms. Patients who have bleeding problems , s uch as a bleeding peptic ulcer, mus t not take cilos tazol. Cilostazol decreases the ability of blood particles, called platelets, to stick together and this can increase the risk of bleeding. It is important that you discuss with your doctor whether you have CHF or bleeding problems. Over 1,300 patients took cilostazol in studies that lasted for 3 to 6 months. The mortality rate in these patients was similar to placebo (less than 1%). These studies were too small to be sure there is not some increased risk of dying with longer use or in patients sicker than those in the studies. How should cilostazol be taken? Follow your doctor's advice about how to take cilostazol. You should take cilostazol twice a day, at least one half-hour before or two hours after breakfast and dinner. Take cilostazol at about the same times each day. Do not share cilostazol with anyone else. It was prescribed only for you. Keep cilostazol and all drugs out of the reach of children. Can cilostazol be taken with other drugs? Certain drugs and foods can increase the amount of cilostazol in the blood. Because of this, your doctor

may adjust your dose of cilostazol or even stop it if you are taking or are going to take one of the following medications. Drugs Interacting With Cilostazol Generic Name (Brand Name) Type of Drug erythromycin (such as E.E.S. , Erythrocin ) Antibiotic ketoconazole (Nizoral ), itraconazole (Sporanox ) Antifungal diltiazem (Cardizem ) Antihypertensive omeprazole (Prilosec ) Gastric acid reducer This list does not include every drug that may interact with cilostazol. Therefore, you should tell your doctor about all medications that you are taking, including vitamins, herbal supplements and over-the- counter drugs you can buy without a prescription. You should also check with your doctor before taking a new medication after you have begun cilostazol. What are the possible side effects of cilostazol? Cilostazol may cause side effects including headache, diarrhea, abnormal stools, increased heart rate, and palpitations. You should discuss possible side effects with your doctor before taking cilostazol and any time you think you are having a side effect. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800- FDA-1088. This provides only a summary of information about cilostazol. If you have any questions about cilostazol, talk to your doctor. Rev. July 2009 MF # 334- Manufactured and Distributed by: Corepharma LLC Middlesex, NJ 08846 CILOSTAZOL 100MG LABEL IMAGE ® ® ® ® ® ®

Revised: 3/2010 STAT RX USA LLC