Evaluate the Efficacy and Safety of Pletaal (Cilostazol) in Subjects With Vasospastic Angina

A Multicenter, Randomized, Double-Blind, Placebo-controlled, Parallel group, Therapeutic exploratory Study.

The subject who has at least an episode of chest pain weekly despite Amlodipine 5mg once a day (qd) taking during 2 weeks will have treatment of Pletaal (Cilostazol) or Placebo for 4 weeks. Pletaal (Cilostazol) is taken 100mg oral tablets two times a day (bid) during 2 weeks after dosing of Pletaal (Cilostazol) 50mg oral tablets bid during 2 weeks. Placebo of Pletaal (Cilostazol) is used as the control medication.

Inclusion criteria

• Male or female over the age of 20 and under the age of 80
• Diagnosis of vasospastic angina
• At least one episode of chest pain weekly during the Amlodipine run in period for 2 weeks

Exclusion criteria

• Currently taking or has taken Cilostazol within the last 3 month before the screening.
• Taking oral antiplatelet agents such as Aspirin, Clopidogrel after Amlodipine run-in period.
• Oral anticoagulants such as Warfarin within the last a month before the screening.
• Currently taking any of the following medications or has taken any of the following medications within the last a week before the screening:

• Other Calcium channel blockers than Amlodipine
• Beta-blocker, or Alpha-blocker
• Oral Nitrate, Nicorandil, except sublingual Nitroglycerin as required(PRN)
• Vitamin E preparations
• Estrogens
• History of Myocardial infarction or Myocardial infarction by vasospastic angina at screening
• History of life threatening vasospastic events such as ventricular tachycardia , ventricular fibrillation, or syncope
• History of stroke, intracranial hemorrhage, or Transient Ischemic Attack(TIA)
• Hemorrhage (hemophilia, capillary fragility, intracranial hemorrhage, upper gastrointestinal hemorrhage, urinary hemorrhage, hemoptysis, vitreous hemorrhage, etc.) or such tendency (active peptic ulcer, hemorrhagic stroke within past 6 months, a case hemorrhage is suspected by wound for surgery within 3 months, proliferative diabetic retinopathy and uncontrolled hypertension)
• History of clinically significant hypersensitivity to the substances of Cilostazol, Amlodipine, Nitroglycerin or dihydropyridine
• Patients with severe aortic valvular stenosis
• History of shock
• Hypotension of diastolic pressure < 90 mmHg at screening
• History of clinically significant hypersensitivity to the substances of Nitrates
• Patients with severe anemia of Hemoglobin ≤ 6.5 g/dl at screening
• History of glaucoma
• Electrocardiogram(ECG) abnormality precluding interpretation of ST change at screening
• Congestive heart failure with less than 40% of left ventricular ejection fraction within the last 3 month before the screening or screening period
• Atrial fibrillation or valvular heart disease, more than moderate severity
• Suspected or identified spasm of left main coronary artery, result of coronary angiography or coronary angiography in the ergonovine induced coronary spasm provocation test
• History of Coronary artery bypass graft(CABG) or percutaneous coronary intervention(PCI)
• Tachycardia; Heart rate > 100 bpm, at Screening
• Uncontrolled hypertension, defined as ≥ 160 mmHg systolic or ≥ 100 mmHg diastolic at Screening
• Creatinine ≥ 1.5 mg/dL at screening
• Aspartate transaminase (AST) or alanine transaminase (ALT) > 3 times the upper limit of normal (ULN) at screening
• Platelet < 100,000 mm3 at screening
• QT prolongation defined as baseline QTc > 450 msec for males or > 470 msec for females at Screening.
• Women who have the possible of pregnancy, or positive urine or blood pregnancy test at screening
• Women who are not using a reliable method of birth control, who are pregnant, or who are breast-feeding
• Drug compliance of Amlodipine < 80% during the Amlodipine run in period for 2 weeks
• Otherwise judged by the investigator to be inappropriate for inclusion in the trial.