Trial to Evaluate the Efficacy and Safety of a Combination Therapy of Candesartan and Amlodipine Versus Candesartan Monotherapy in Hypertensive Patients Inadequately Controlled by Candesartan Monotherapy

Inclusion criteria

• Age of 19 or above
• Inadequately controlled Essential hypertension at Screening

• Drug naive or didn't take antihypertensive drug within 2 weeks prior to Visit 1

• Mean sitDBP ≥ 95mmHg on target arm
• Taking antihypertensive drug but not controlled

• Mean sitDBP ≥ 90mmHg on target arm
• Inadequately controlled after 4 weeks of Candesartan 16mg monotherapy

• Mean sitDBP at Visit 2 ≥ 90mmHg on target arm
• Ability to provide written informed consent

Exclusion criteria

• The change of mean sitDBP ≥ 10mmHg or mean sitSBP ≥ 20mmHg on target arm at Visit 1
• Mean sitDBP ≥ 120mmHg or mean sitSBP ≥ 200mmHg on target arm at Visit 1 and Visit 2
• Known to suspected Stage 2 Hypertension(aortic coarctation, Primary hyperaldosteronism, renal artery stenosis, pheochromocytoma)
• Patient with congestive heart failure(NYHA class III, IV)
• Patient with unstable angina pectoris, myocardial infarction, Valvular heart disease, arrhythmia(treatment required) within 3 months
• History of stroke, cerebral hemorrhage within 6 months
• Type I Diabetes mellitus, Type II Diabetes mellitus with HbA1c > 8.5%
• History of severe or malignant retinopathy
• AST/ALT > UNL*3, Serum creatinine > UNL*1.5, K > 5.5mEq/L
• Patient with acute or chronic inflammatory(treatment required) status
• Patient who need to take antihypertensive drug besides Investigational products
• Patient must be treated with medications prohibited for concomitant use during the study period
• History of angioedema related to ACE inhibitor or angiotensin II receptor blockers
• Hypersensitive to Candesartan/Amlodipine
• Patient who are dependent on drugs or alcohol within 6 months
• History of disability to drug ADME, active inflammatory bowel syndrome within 12months, impaired pancreatic function, GI bleeding, obstructions of urinary tract
• Patients treated with other investigational product within 30 days at first time taking the investigational product
• Women with pregnant, breast-feeding
• History of malignant tumor within 5 years
• Not eligible to participate for the study at the discretion of investigator