Inclusion Criteria:

• Having an average value of ≥ 95 mmHg and ≤ 109 mmHg in diastolic blood pressure measurement or an average diastolic blood pressure value of ≥ 85 mmHg in 24-hours arterial blood pressure measurement,
• Received no treatment within the last 3 months.

Exclusion Criteria:

• Premenopausal women having at least one of the following conditions,

  • Not surgically sterile,
  • Are nursing,
  • Having childbearing potential and not using a reasonable contraception method or not thinking to continue the method throughout the study. Reasonable contraception methods are: intrauterine device, oral or implantable or injectable contraception methods. No methods other than these are accepted.
• Patients routinely sleeping within the day since she/he works at nightshift and whose working hours continue in a time shift from midnight to 04:00 A.M.
• Patients with average systolic blood pressure = 180 mmHg in sitting position or average diastolic blood pressure is ≥110 mmHg in sitting position at baseline visit
• Having known or suspected secondary hypertension

• Having renal and/or hepatic failure together with the following laboratory criteria:

  • Having elevated values of SGPT (ALT) or SGOT (ALT) (at least twice the upper limit of normal range)
  • Having serum creatinine levels of > 2.3 mg/dL (or > 203 μmol/L)
• With bilateral renal artery stenosis or single kidney and unilateral renal artery stenosis or those in post-renal transplantation or with single kidney,
• Having symptomatic sodium insufficiency, hypokalemia or hyperkalemia,
• With volume deficiency,
• With primary hyperaldosteronism,
• With biliary obstructive disorders,
• Having congestive heart failure (New York Heart Association (NYHA)-functional class CHF III-IV),
• With unstable angina pectoris occurring within 3 months before he or she signed the informed consent.
• With stroke occurring within 6 months before he or she signed the informed consent,
• With myocardial infarction or having cardiac surgery within three months before he or she signed the informed consent,
• Underwent PTCA (percutaneous transluminal coronary revascularization) within three months before he or she signed the informed consent,
• Having continuous tachycardia, atrial fibrillation, atrial flutter or other clinical arrythmias defined by the investigator
• With hypertrophic obstructive cardiomyopathy, aortic stenosis, hemodynamically related aortic or mitral valve stenosis,
• With insulin-dependant diabetes mellitus whose blood sugar regulation could not be controlled within the last 3 months after a HbA1C measurement in which it is equal to 10%.
• With a history of drug or alcohol addiction within the last 6 months before she or he signed the informed consent,
• Receiving a drug other than those defined in protocol for blood pressure regulation,
• Who have been participated in any investigational study within the prior month before she or he signed the informed consent
• With a known hypersensitivity against any drug which will be used.

The above information is not intended to contain all considerations relevant to a patient's potential participation in a clinical trial.