Combination of Olmesartan and Hydrochlorothiazide in Essential Hypertension

Inclusion Criteria: * Male or female Europeans aged 18 years or older with moderate to severe HTN, defined as follows (conventional BP measurements) Exclusion Criteria: * Female patients of childbearing potential pregnant, lactating or planning to become pregnant during the trial period. * Patients with serious disorders which may limit the ability to evaluate the efficacy or safety of the study medication, including cerebrovascular, cardiovascular, renal, respiratory, hepatic, gastrointestinal, endocrine or metabolic, haematological or oncological, neurological and psychiatric diseases. * Patients having a history of the following within the last six months: * myocardial infarction, * unstable angina pectoris, * percutaneous coronary intervention, * severe heart failure, * hypertensive encephalopathy, cerebrovascular accident (stroke) or * transient ischaemic attack. * Patients with clinically significant abnormal laboratory values at screening. * Patients with secondary HTN.