Efficacy and Safety of Valsartan and Amlodipine in Patients With Essential Hypertension

Inclusion criteria * Patients with essential hypertension measured by electronic hemodynamometer. - - Patients must satisfy the following criteria. 1. MSDBP \<110 mmHg and MSSBP \<180 mmHg at Visit 1 2. MSDBP ≥ 90 mmHg and \< 110 mmHg and MSSBP \< 180 mmHg at Visit 2 3. MSDBP ≥ 95 mmHg and \< 110 mmHg and MSSBP \< 180 mmHg at Visit 3 4. The absolute difference in MSDBP between Visit 2 and 3 is ≤ 10 mmHg * Male or female outpatients. * Aged =\> 20 and =\< 80 years (at the time of signing informed consent). * Patients who have written informed consent to participate in this study. Exclusion criteria * Pregnant women, nursing (lactating) mothers, women suspected of being pregnant, or women who wish to be pregnant during the study, women of child-bearing potential. * Patients with secondary hypertension or suspected of having secondary hypertension. * Patients with a history of malignant hypertension. * Patients with an inability to completely discontinue all prior antihypertensive medications safely for a period of 12 weeks as required by the protocol. * Patients with or with a history of any of the following diseases or signs: Cardiac disease, renal disease, cerebrovascular disorder * Patients with a clinically significant allergy (asthma on pharmacotherapy, multi-drug allergy, or drug-induced or food-induced anaphylactic reactions). * Patients hypersensitive to AII receptor antagonists, calcium channel blockers or dihydropyridine derivatives. * Known moderate or malignant retinopathy. * Patients with or with a history of pancreatitis. Patients with pancreatic injury, or evidence of impaired pancreatic function/injury within 12 months of Visit 1. * Patients with any surgical or medical condition which might significantly alter the absorption, distribution, metabolism, or excretion of any drug. * Patients with volume depletion based on the investigator's or subinvestigator's clinical judgment using vital signs, skin turgor, moistness of mucous membrane and laboratory values. * Patients who are found to have low Na and K (Na \<130 mEq/L, K \<3.3mEq/L) or high in these parameters (Na ≥ 152 mEq/L, K ≥ 5.2 mEq/L) by laboratory tests at Visit 1. * Patients with type I diabetes mellitus on treatment with insulin, or patients with type II diabetes with poor glucose control defined as a glycosylated hemoglobin (HbA1c) \> 8.0% at Visit 1. * Patients with or with a history of malignant tumors including leukemia and lymphoma, treated or untreated, within the past 5 years of Visit 1 whether or not there is evidence of local recurrence or metastases (except for localized basal cell carcinoma of the skin). * Patients with any severe, life-threatening disease within the past 5 years. Patients with a history of autoimmune diseases such as rheumatoid arthritis and systemic lupus erythematosus. * Any surgical or medical condition, which in the opinion of the investigator or subinvestigator, place the patient at higher risk from his/her participation in the study, or are likely to prevent the patient from complying with the requirement of the study or completing the trial period. * Patients who have with or with a history of drug or alcohol abuse within the last 2 years of Visit 1. Patients who have received other investigational product within 12 weeks of Visit 1. * Any chronic inflammatory condition needing chronic anti-inflammatory drug therapy. * Persons directly involved in the execution of this study. * Patients who are considered unlikely to comply with the requirements specified in the protocol by the investigator or subinvestigator.