Evaluation of Effect of Combination With Telmisartan and Hydrochlorothiazide in Hypertensives Uncontrolled on Amlodipine

Inclusion Criteria: * 5 mg/day of amlodipine is administered for more than 3 months * Systolic or diastolic blood pressure \>= 140/90 mmHg (more than 2 times measurements at outpatient clinic before start of the study) * Outpatients Exclusion Criteria: * Secondary hypertension including renovascular hypertension with single kidney or bilateral stenosis * Administration of antihypertensives other than amlodipine * Cardiovascular disease (cerebral hemorrhage, cerebral infarction, TIA, angina, myocardial infarction, acute renal failure) occurs less than 6 months before start of the study * Serum creatinine \>= 2.0 mg/dl * Severe hypertension (systolic or diastolic blood pressure \>= 180/110 mmHg) or malignant hypertension (hypertensive organ damage is rapidly developing) * Chronic heart failure (NYHA class\>=III to VI) * Contraindication of telmisartan or hydrochlorothiazide * Hyper- (\>= 5.5 mEq/L) or hypo- (\<=3.5 mEq/l) potassemia * Untreated hyperuricemia or uncontrolled hyperuricemia (serum uric acid \>= 8.0 mg/dl) * Diabetic patients who require insulin therapy, uncontrolled diabetic patients (hemoglobin A1c \>=9.0%), or patients who possess the risk of hypoglycemic attack * Patients inadequate for the study