Cilostazol

369.46

369.46

1312995-182-4

N7Z035406B

758936

DTXSID9045132

C1051

Colorless needle-like crystals from methanol

B - Blood and blood forming organs

2933990090

81.9

3.1

off-white solid

1.3±0.1 g/cm3

160 °C

664.7ºC at 760 mmHg

355.8±31.5 °C

1.676

DMSO: 18 mg/mL, soluble

Store at RT

4.14X10-11 mm Hg at 25 deg C (est)

LD50 in mice, rats (mg/kg): >2000, >2000 i.p.; >5000, >5000 orally (Nomura)

Henry's Law constant = 1.48X10-13 atm-cu m/mol at 25 °C (est)

199.7 Ų [M+H]+ [CCS Type: TW, Method: calibrated with polyalanine and drug standards]

Hydroxyl radical reaction rate constant = 5.63X10-11 cu cm/molec-sec at 25 °C (est)

NONH for all modes of transport

2

VC8277500

Xi

Stable under recommended storage conditions.

P201, P202, P281, P308+P313, P405, P501

H361

SRP: Expired or waste pharmaceuticals shall carefully take into consideration applicable DEA, EPA, and FDA regulations. It is not appropriate to dispose by flushing the pharmaceutical down the toilet or discarding to trash. If possible return the pharmaceutical to the manufacturer for proper disposal being careful to properly label and securely package the material. Alternatively, the waste pharmaceutical shall be labeled, securely packaged and transported by a state licensed medical waste contractor to dispose by burial in a licensed hazardous or toxic waste landfill or incinerator.|Product: Offer surplus and non-recyclable solutions to a licensed disposal company; Contaminated packaging: Dispose of as unused product.

Incompatible materials: Strong oxidizing agents

The Approved Drug Products with Therapeutic Equivalence Evaluations identifies currently marketed prescription drug products, including cilostazol, approved on the basis of safety and effectiveness by FDA under sections 505 of the Federal Food, Drug, and Cosmetic Act.

|Warning|H361 (100%): Suspected of damaging fertility or the unborn child [Warning Reproductive toxicity]|P201, P202, P281, P308+P313, P405, and P501|Aggregated GHS information provided by 2 companies from 2 notifications to the ECHA C&L Inventory.

Eye/face protection: Use equipment for eye protection tested and approved under appropriate government standards such as NIOSH (US) or EN 166(EU).|Skin protection: Handle with gloves.|Body Protection: Choose body protection in relation to its type, to the concentration and amount of dangerous substances, and to the specific work-place. The type of protective equipment must be selected according to the concentration and amount of the dangerous substance at the specific workplace.|Respiratory protection: Respiratory protection is not required. Where protection from nuisance levels of dusts are desired, use type N95 (US) or type P1 (EN 143) dust masks. Use respirators and components tested and approved under appropriate government standards such as NIOSH (US) or CEN (EU).

Suitable extinguishing media: Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide.|Advice for firefighters: Wear self-contained breathing apparatus for firefighting if necessary.

ACCIDENTAL RELEASE MEASURES: Personal precautions, protective equipment and emergency procedures: Avoid dust formation. Avoid breathing vapors, mist or gas; Environmental precautions: Do not let product enter drains; Methods and materials for containment and cleaning up: Sweep up and shovel. Keep in suitable, closed containers for disposal.

Precautions for safe handling: Provide appropriate exhaust ventilation at places where dust is formed. Normal measures for preventive fire protection.|Appropriate engineering controls: General industrial hygiene practice.|Gloves must be inspected prior to use. Use proper glove removal technique (without touching glove's outer surface) to avoid skin contact with this product. Dispose of contaminated gloves after use in accordance with applicable laws and good laboratory practices. Wash and dry hands.|SRP: Local exhaust ventilation should be applied wherever there is an incidence of point source emissions or dispersion of regulated contaminants in the work area. Ventilation control of the contaminant as close to its point of generation is both the most economical and safest method to minimize personnel exposure to airborne contaminants. Ensure that the local ventilation moves the contaminant away from the worker.

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 oral LD50 of cilostazol is >5.0 g/kg in mice and rats and >2.0 g/kg in dogs.|IDENTIFICATION AND USE: Cilostazol forms colorless, needle-like crystals. As the oral drug Pletal, it is indicated for the reduction of symptoms of intermittent claudication. HUMAN EXPOSURE AND TOXICITY: The signs and symptoms of an acute overdose may include severe headache, diarrhea, hypotension, tachycardia, and possibly cardiac arrhythmias. ANIMAL STUDIES: 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 maximum recommended human dose (MRHD). Repeated oral administration of cilostazol to dogs 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, AUC to unbound cilostazol was less than that seen in humans at the MRHD of 100 mg twice daily. 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, 14th rib, and retarded ossification). 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. Dietary administration of cilostazol to rats and mice for up to 104 weeks 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.

In publications of the multiple, large prospective trials of cilostazol therapy, rates of serum ALT elevations during therapy were not provided. Furthermore, there were no reported instances of clinically apparent acute liver injury. Since its approval and wide scale use, there have been no published reports of hepatotoxicity attributed to cilostazol. Nevertheless, the current product label mentions that instances of serum enzyme elevations and hepatitis have been reported to the sponsor. The time of onset, clinical pattern and course of liver test abnormalities during cilostazol therapy have not been reported.

Pharmacokinetic interaction (increased plasma concentrations of active metabolite 3,4-dehydro-cilostazol) with CYP2C19 inhibitors, including omeprazole; use with caution and consider reduced dosage.|Potential pharmacokinetic interaction (increased plasma lovastatin concentrations and decreased plasma cilostazol concentration) with lovastatin, a substrate for CYP3A4, although unlikely to be clinically important.|Pharmacokinetic interaction (increased plasma cilostazol concentrations); use with caution and consider reduced dosage. Potential pharmacokinetic interaction (increased plasma cilostazol concentrations, decreased clearance) with other inhibitors of CYP3A4 isoenzyme, including, but not limited to, certain azole antifungals (e.g., fluconazole, itraconazole, ketoconazole, miconazole), certain macrolide antibiotics (e.g., erythromycin or clarithromycin but not azithromycin), certain selective serotonin-reuptake inhibitors (e.g., fluoxetine, fluvoxamine, nefazodone, sertraline), certain antiretroviral agents (e.g., indinavir), metronidazole, diltiazem, and danazol.|Potentially additive antiplatelet effects with clopidogrel and cilostazol. Caution is advised and bleeding times should be monitored during such concomitant therapy. Pharmacokinetic interaction unlikely.|For more Interactions (Complete) data for Cilostazol (10 total), please visit the HSDB record page.

LD50 Dog oral > 2 g/kg|LD50 Rat oral > 5 g/kg|LD50 Mouse oral > 5 g/kg

WARNING: CONTRAINDICATED IN HEART FAILURE PATIENTS. Pletal is contraindicated in patients with heart failure of any severity. 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 heart failure.|Cilostazol may induce tachycardia, palpitation, tachyarrhythmia or hypotension. The increase in heart rate associated with cilostazol is approximately 5 to 7 bpm. Patients with a history of ischemic heart disease may be at risk for exacerbations of angina pectoris or myocardial infarction.

95-98%

Indicated for the alleviation of symptoms of intermittent claudication (pain in the legs that occurs with walking and disappears with rest).

Cilostazol is a quinolinone derivative that inhibits specific cellular phosphadiesterases, which cause arterial vasodilation and inhibition of platelet function and makes it a valuable as a therapy of intermittent claudication and as a means of secondary prevention of stroke. Cilostazol has not been associated with serum enzyme elevations during therapy or with published instances of clinically apparent liver injury.

Intermittent Claudication Agents

/CLINICAL TRIALS/ ClinicalTrials.gov is a registry and results database of publicly and privately supported clinical studies of human participants conducted around the world. The Web site is maintained by the National Library of Medicine (NLM) and the National Institutes of Health (NIH). Each ClinicalTrials.gov record presents summary information about a study protocol and includes the following: Disease or condition; Intervention (for example, the medical product, behavior, or procedure being studied); Title, description, and design of the study; Requirements for participation (eligibility criteria); Locations where the study is being conducted; Contact information for the study locations; and Links to relevant information on other health Web sites, such as NLM's MedlinePlus for patient health information and PubMed for citations and abstracts for scholarly articles in the field of medicine. Cilostazol is included in the database.|Pletal is indicated for the reduction of symptoms of intermittent claudication, as demonstrated by an increased walking distance. /Included in US product label/|Because of its antiplatelet activity, cilostazol has been used alone or in combination with other antiplatelet agents (e.g., aspirin, clopidogrel) to prevent thrombosis and restenosis following coronary angioplasty/stent implantation. /NOT included in US product label/|Cilostazol has been used for the secondary prevention of stroke in patients with a history of noncardioembolic stroke or transient ischemic attacks (TIAs). /NOT included in US product label/|/EXPL THER/ We conducted a randomized, double blind, placebo controlled trial to assess the efficacy and safety of cilostazol, a selective inhibitor of phosphodiesterase 3, in patients with vasospastic angina (VSA). Cilostazol has been shown to induce vascular dilatation, but its efficacy in patients with VSA is unknown. Between October 2011 and July 2012, 50 patients with confirmed VSA who had >/= 1 angina episodes/week despite amlodipine therapy (5 mg/day) were randomly assigned to receive either cilostazol (up to 200 mg/day) or placebo for 4 weeks. All patients were given diaries to record the frequency and severity of chest pain (0-10 grading). The primary endpoint was the relative reduction of the weekly incidence of chest pain. Baseline characteristics were similar between the two groups. Among 49 evaluable patients (25 in the cilostazol group, 24 in the placebo group), the primary endpoint was significantly greater in the cilostazol group compared with the placebo group (-66.5 +/- 88.6% vs -17.6 +/- 140.1%, respectively, p=0.009). The secondary endpoints, including a change in the frequency of chest pain (-3.7 +/- 0.5 vs -1.9 +/- 0.6, respectively, p=0.029), a change in the chest pain severity scale (-2.8 +/- 0.4 vs -1.1 +/- 0.4, respectively, p=0.003), and the proportion of chest pain-free patients (76.0% vs 33.3%, respectively, p=0.003) also significantly favoured cilostazol. Headache was the most common adverse event in both groups (40.0% vs 20.8%, respectively, p=0.217). Cilostazol is an effective therapy for patients with VSA uncontrolled by conventional amlodipine therapy, and has no serious side effects.

/BOXED WARNING/ WARNING: CONTRAINDICATED IN HEART FAILURE PATIENTS. Pletal is contraindicated in patients with heart failure of any severity. 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 heart failure.|Rare cases of thrombocytopenia or leukopenia progressing to agranulocytosis have been reported when cilostazol was not immediately discontinued; agranulocytosis was reversible with discontinuance of cilostazol.|Information is limited regarding the safety and efficacy of concurrent use of cilostazol and clopidogrel. Currently it is unknown whether concurrent therapy with cilostazol and clopidogrel has additive effects on bleeding time. Caution should be used and bleeding times monitored during such concurrent therapy.|Cilostazol may induce tachycardia, palpitation, tachyarrhythmia or hypotension. The increase in heart rate associated with cilostazol is approximately 5 to 7 bpm. Patients with a history of ischemic heart disease may be at risk for exacerbations of angina pectoris or myocardial infarction.|For more Drug Warnings (Complete) data for Cilostazol (10 total), please visit the HSDB record page.

Cilostazol reduces the symptoms of intermittent claudication, as indicated by an increased walking distance. Intermittent claudication is pain in the legs that occurs with walking and disappears with rest. The pain occurs due to reduced blood flow to the legs.

Agents that cause an increase in the expansion of a bronchus or bronchial tubes. (See all compounds classified as Bronchodilator Agents.)|Drugs or agents which antagonize or impair any mechanism leading to blood platelet aggregation, whether during the phases of activation and shape change or following the dense-granule release reaction and stimulation of the prostaglandin-thromboxane system. (See all compounds classified as Platelet Aggregation Inhibitors.)|Fibrinolysin or agents that convert plasminogen to FIBRINOLYSIN. (See all compounds classified as Fibrinolytic Agents.)|Drugs intended to prevent damage to the brain or spinal cord from ischemia, stroke, convulsions, or trauma. Some must be administered before the event, but others may be effective for some time after. They act by a variety of mechanisms, but often directly or indirectly minimize the damage produced by endogenous excitatory amino acids. (See all compounds classified as Neuroprotective Agents.)|Drugs used to cause dilation of the blood vessels. (See all compounds classified as Vasodilator Agents.)|Compounds that specifically inhibit PHOSPHODIESTERASE 3. (See all compounds classified as Phosphodiesterase 3 Inhibitors.)

Cilostazol is absorbed after oral administration. A high fat meal increases absorption, with an approximately 90% increase in C_max 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. Cilostazol is eliminated predominately by metabolism and subsequent urinary excretion of metabolites. The primary route of elimination was via the urine (74%), with the remainder excreted in feces (20%). No measurable amount of unchanged cilostazol was excreted in the urine, and less than 2% of the dose was excreted as 3,4-dehydro-cilostazol. About 30% of the dose was excreted in urine as 4'-trans-hydroxy-cilostazol.|/MILK/ Transfer of cilostazol into milk has been reported in rats.|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.|Pletal is absorbed after oral administration. A high fat meal increases absorption, with an approximately 90% increase in Cmax and a 25% increase in AUC. Absolute bioavailability is not known.|The primary route of elimination was via the urine (74%), with the remainder excreted in feces (20%). No measurable amount of unchanged cilostazol was excreted in the urine, and less than 2% of the dose was excreted as 3,4-dehydro-cilostazol. About 30% of the dose was excreted in urine as 4'-trans-hydroxy-cilostazol. The remainder was excreted as other metabolites, none of which exceeded 5%. There was no evidence of induction of /microsomal enzymes/.|For more Absorption, Distribution and Excretion (Complete) data for Cilostazol (7 total), please visit the HSDB record page.

Hepatic. 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.|Following oral administration of 100 mg radiolabeled cilostazol, 56% of the total analytes in plasma was cilostazol, 15% was 3,4-dehydro-cilostazol (4-7 times as active as cilostazol), and 4% was 4'-trans-hydroxy-cilostazol (20% as active as cilostazol).|Cilostazol is eliminated predominantly by metabolism and subsequent urinary excretion of metabolites. Based on in vitro studies, the primary isoenzymes involved in cilostazol's metabolism are CYP3A4 and, to a lesser extent, CYP2C19. The enzyme responsible for metabolism of 3,4-dehydro-cilostazol, the most active of the metabolites, is unknown.|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 Pletal.|The pharmacokinetics of cilostazol was investigated after oral and intravenous administration in both male and female rats. After oral administration, area under serum concentration-time curve (AUC) was about 35-fold higher in female rats than in male rats, and absolute bioavailability was about 5.8-fold higher in female rats than in male rats. Total body clearance (CL(total)) for female rats was around one-sixth of that for male rats. In vivo hepatic clearance (CL(h)) calculated based on isolated liver perfusion studies was even higher than or around 90% of the in vivo CL(total) of cilostazol for female and male rats, respectively, indicating that cilostazol is mainly eliminated by the liver in both male and female rats. In vitro metabolism studies utilizing hepatic microsomes and recombinant cytochrome (CYP) isoforms clearly indicated that major metabolites of cilostazol were generated extensively with hepatic microsomes of male rats and that male-predominant CYP3A2 and male-specific CYP2C11 were mainly responsible for the hepatic metabolism of cilostazol. Therefore, the great sex differences in the pharmacokinetics of cilostazol were mainly attributed to the large difference in hepatic metabolism. Our experimental results also suggested that the substantial metabolism of cilostazol in the small intestine and its possible saturation would be responsible for dose-dependent bioavailability in both male and female rats.|The primary route of elimination was via the urine (74%), with the remainder excreted in feces (20%). No measurable amount of unchanged cilostazol was excreted in the urine, and less than 2% of the dose was excreted as 3,4-dehydro-cilostazol. About 30% of the dose was excreted in urine as 4'-trans-hydroxy-cilostazol. The remainder was excreted as other metabolites, none of which exceeded 5%. There was no evidence of induction of /microsomal enzymes/.|Cilostazol has known human metabolites that include OPC-13217 and OPC-13326.

11-13 hours.|Cilostazol and its active metabolites have apparent elimination half-lives of about 11-13 hours.

Cilostazol and several of its metabolites are cyclic AMP (cAMP) phosphodiesterase III inhibitors (PDE III inhibitors), inhibiting phosphodiesterase activity and suppressing cAMP degradation with a resultant increase in cAMP in platelets and blood vessels, leading to inhibition of platelet aggregation and vasodilation.|Cilostazol, a phosphodiesterase 3, has been widely used in patients with arterial disease and is known to have additional beneficial effects on dyslipidemia. However, the effect of cilostazol on hepatic steatosis has not been fully elucidated. We investigated the effect of cilostazol on hepatic ABCA1 expression and hepatic steatosis in diet-induced obesity mice model. Hepatic ABCA1 expression and lipid accumulation were analyzed in HepG2 cell lines treated with cilostazol. Male C57BL/6 mice were randomly divided into three groups: (1) fed normal chow diet with vehicle; (2) fed high-fat diet (HFD) with vehicle; (3) fed HFD with cilostazol. Cilostazol (30 mg/kg) was orally administered once daily for 9 weeks. Cilostazol significantly enhanced ABCA1 expression and restored ABCA1 expression reduced by palmitate in HepG2 cells. Cilostazol treatment ameliorated lipid accumulation induced by palmitate, and this effect was diminished when ABCA1 or LRP1 was silenced by small interference RNA. After silencing of LRP1, ABCA1 expression was decreased in HepG2 cells. Cilostazol significantly enhanced hepatic ABCA1 expression and decreased hepatic fat in HFD-fed mice. Hepatic expression of cleaved caspase-3 and PARP1 was also decreased in HFD-fed mice treated with cilostazol. Cilostazol ameliorated hepatic steatosis and increased ABCA1 expression in the hepatocytes. Enhancing ABCA1 expression with cilostazol represents a potential therapeutic avenue for treatment of hepatic steatosis.|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.

/SRP:/ Immediate first aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR if necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on the left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Poisons A and B/|/SRP:/ Basic treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if needed. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for pulmonary edema and treat if necessary ... . Monitor for shock and treat if necessary ... . Anticipate seizures and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with 0.9% saline (NS) during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 mL/kg up to 200 mL of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool ... . Cover skin burns with dry sterile dressings after decontamination ... . /Poisons A and B/|/SRP:/ Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in severe respiratory distress. Positive-pressure ventilation techniques with a bag valve mask device may be beneficial. Consider drug therapy for pulmonary edema ... . Consider administering a beta agonist such as albuterol for severe bronchospasm ... . Monitor cardiac rhythm and treat arrhythmias as necessary ... . Start IV administration of D5W TKO /SRP: "To keep open", minimal flow rate/. Use 0.9% saline (NS) or lactated Ringer's (LR) if signs of hypovolemia are present. For hypotension with signs of hypovolemia, administer fluid cautiously. Watch for signs of fluid overload ... . Treat seizures with diazepam or lorazepam ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Poisons A and B/

/SIGNS AND SYMPTOMS/ Cilostazol may induce tachycardia, palpitation, tachyarrhythmia or hypotension. The increase in heart rate associated with cilostazol is approximately 5 to 7 bpm. Patients with a history of ischemic heart disease may be at risk for exacerbations of angina pectoris or myocardial infarction.|/SIGNS AND SYMPTOMS/ 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.|/CASE REPORTS/ Cilostazol, a phosphodiesterase III inhibitor, is known to increase the heart rate; however, its effects on glucose metabolism remain unclear. We observed that the blood glucose level varied in parallel with the heart rate immediately after starting or stopping cilostazol therapy in three patients with type 2 diabetes. This finding indicates that cilostazol induces hyperglycemia and tachycardia in a portion of diabetic patients, presumably via similar pharmacological effects on different organs. Much more attention should be paid to the possible effects of cilostazol on glycemic control, including taking into consideration the risk-benefit ratio of cilostazol use and individual circumstances.|/ALTERNATIVE and IN VITRO TESTS/ Cilostazol, a selective phosphodiesterase 3 (PDE3) inhibitor, is known as an anti-platelet drug and acts directly on platelets. Cilostazol has been shown to exhibit vascular protection in ischemic diseases. Although vascular endothelium-derived prostaglandin I2 (PGI2) plays an important role in vascular protection, it is unknown whether cilostazol directly stimulates PGI2 synthesis in endothelial cells. Here, we elucidate the mechanism of cilostazol-induced PGI2 stimulation in endothelial cells. Human aortic endothelial cells (HAECs) were stimulated with cilostazol and PGI2 accumulation in the culture media was measured. Cilostazol increased PGI2 synthesis via the arachidonic acid pathway. Cilostazol-induced intracellular calcium also promoted PGI2 synthesis via the inositol 1,4,5-trisphosphate receptor. Using RNAi, silencing of PDE3B abolished the induction effect of cilostazol on PGI2 synthesis and intracellular cAMP accumulation. Inhibition of the exchange protein, which was directly activated by cyclic AMP 1 (Epac-1) and its downstream signal the Ras-like small GTPase (Rap-1), abolished cilostazol-induced PGI2 synthesis, but this did not take place via protein kinase A (PKA). Inhibition of downstream signaling, such as mitogen-activated protein kinase (MAPK), phosphoinositide 3-kinase (PI3K) gamma, and phospholipase C (PLC) e, suppressed cilostazol-induced PGI2 synthesis. The PDE3/Epac-1/Rap-1 signaling pathway plays an important role in cilostazol-induced PGI2 synthesis. Namely, stimulation of HAECs with cilostazol induces intracellular calcium elevation via the Rap-1/PLCe/IP3 pathway, along with MAPK activation via direct activation by Epac-1/Rap-1 and indirect activation by Epac-1/Rap-1/PI3Kgamma, resulting in synergistically induced PGI2 synthesis.|For more Human Toxicity Excerpts (Complete) data for Cilostazol (8 total), please visit the HSDB record page.

6-(4-(1-cyclohexyl-1H-tetrazol-5-yl)butoxy)-3,4-dihydro-2(1H)-quinolinone

Table: Cilostazol Preparations [Table#8337]

HPLC determination in plasma.

Human Drugs -> FDA Approved Drug Products with Therapeutic Equivalence Evaluations (Orange Book) -> Active Ingredients