Irbesartan in Hypertension

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.