Irbesartan/Hydrochlorothiazide (HCTZ) Combination Therapy for Patients With Moderate Hypertension

Inclusion Criteria: * Willing to provide written informed consent * Subjects must have uncontrolled hypertension defined as: * average systolic blood pressure between 160 mmHg and 180 mmHg (while diastolic blood pressure is less than 110 mmHg) or * average diastolic blood pressure between 100 mmHg and 110 mmHg (while systolic blood pressure is between 130 mmHg and 180 mmHg) * Subjects must be willing to discontinue their antihypertensive medication, if applicable. * Men and women, ages 18 and older will be included. * Women of childbearing potential (WOCBP) must be using an adequate method of contraception to avoid pregnancy throughout the study and for up to one week after the study in such a manner that the risk of pregnancy is minimized. WOCBP must have a negative serum or urine pregnancy test within 72 hours prior to the start of study medication. Exclusion Criteria: * Women who are pregnant or breastfeeding * Known or suspected secondary hypertension * Hypertension emergencies or stroke within the past 12 months. * Heart attack, angina or bypass surgery within the past six months. * Significant kidney disease * Significant liver disease * Systemic lupus erythematosus * Gastrointestinal disease or surgery that interfere with drug absorption * Cancer during the past five years excluding localized squamous cell or basal cell carcinoma of the skin * Currently pregnant or lactating * Mental condition (psychiatric or organic cerebral disease) rendering the subject unable to understand the nature, scope, and possible consequences of the study * Drug or alcohol abuse within the last five years * Known allergy to irbesartan or diuretics