Coadministration of Ezetimibe and Simvastatin in Patients With Primary Hypercholesterolemia (P05457)

Inclusion Criteria: * Patients with hypercholesterolemia who satisfy the following criteria: * Patients who have used any of the following HMG-CoA reductase inhibitors (hereinafter referred to as "statins") for 4 weeks or longer before the start of the observation period and whose LDL-cholesterol level during the treatment had not reached lipid management target indicated below * Age: 20 years of age or older (at the time of obtaining informed consent) * Sex: both males and females * Inpatient/outpatient: Out-patients Exclusion Criteria: * Patients for whom any of the following is applicable: * Patients whose fasted triglyceride level measured at the start of the observation period or the treatment period exceeds 500 mg/dL * Patients with homozygous familial hypercholesterolemia * Patients with creatine phosphokinase (CPK) \> 2x upper limit of normal (ULN) measured at the start of the observation period or the treatment period. * Patients with serious hepatic disorder, or patients with alanine aminotransferase (ALT) or aspartate aminotransferase (AST) \> 2x ULN measured at the start of the observation period or the treatment period. * Patients with a history of hypersensitivity to any ingredient of ezetimibe tablets or simvastatin tablets * Pregnant, nursing women, women who may be pregnant, or patients wishing to be pregnant during the study. * Patients who have discontinued use of serum lipid lowering agents for less than 4 weeks at the start of the treatment period (8 weeks in the case of probucol). (However, if the patient had taken a serum lipid lowering agent before the test conducted at the start of the observation period, a period of discontinuation of 27 days, or 55 days in the case of probucol, is allowed.) * Patients who are using cyclosporine from after the start of the observation period * Patients who are using any of the following drug from after the start of the observation period: itraconazole, miconazole, atazanavir, saquinavir mesilate * Patients with a history of ezetimibe use * Patients with hyperlipidemia associated with the following diseases: * Hypothyroidism * Obstructive gall bladder or biliary disease * Chronic renal failure * Pancreatitis * Patients with hyperlipidemia associated with concomitant use of drugs having adverse effect on serum lipids, etc * Patients who have received an investigational drug within 4 weeks of the start of the observation period * Other patients deemed not appropriate for study entry by the investigator