Cilostazol-Simvastatin Drug Interaction Study

Inclusion Criteria: * Healthy male subjects aged 20 - 45 years * With in 20% of ideal body weight, {Ideal body weight=\[height(cm)-100\]\*0.9} * Agreement with written informed consent Exclusion Criteria: * Clinically significant cardiovascular, pulmonary, hepatic, renal, hematologic, gastrointestinal disease or mental disorder (Past history or present) * Inadequate result of laboratory test (especially, AST/ALT \> 1.25 x UNL, Total bilirubin \> 1.5 x UNL) * Positive reaction in the HBs Ag, anti-HCV Ab, anti-HIV Ab, VDRL test * Taking OTC(Over the counter)medicine including oriental medicine within 7 days * Clinically significant allergic disease (Except for mild allergic rhinitis and dermatitis seems to be not need for medication) * Subject with known for hypersensitivity reaction to Cilostazol, Simvastatin or Pravastatin * Previous whole blood donation within 60 days or component blood donation within 30 days * Previous participation of other trial within 90 days * Continued taking caffeine (caffeine \> 5 cup/day), drinking (alcohol \> 30 g/day) and severe heavy smoker (cigarette \> 1/2 pack per day) * An impossible one who participates in clinical trial by investigator's decision including for reason of laboratory test result