Efficacy and Safety of a Single-pill Fixed Combination of Sufficient Losartan/Hydrochlorothiazide in Chinese Hypertensive Patients

1. Study name: Efficacy and safety of a single-pill fixed combination of sufficient losartan/hydrochlorothiazide in Chinese hypertensive patients (FOCUS) 2. Medicine: Losartan 100 mg/hydrochlorothiazide 25 mg single-pill fixed combination; amlodipine besylate tablet (5 mg/tablet); hydrochlorothiazide tablets (25 mg/tablet) 3. Rationale: Angiotensin-converting enzyme inhibitor (ACEI) or angiotensin receptor blocker (ARB) combined with thiazide diuretic (DIU), which is the preferred combination for most hypertension guidelines. However, the efficacy and safety of losartan 100 mg/hydrochlorothiazide 25 mg single-pill fixed combination evaluated by ambulatory blood pressure are still lack of clinical evidence. 4. Objective: To evaluate the efficacy and safety of losartan 100 mg/hydrochlorothiazide 25 mg fixed combination for ambulatory blood pressure after 8 weeks therapy in patients over 18 years with grade 1 or 2 hypertension either newly diagnosed or with blood pressure not controlled with monotherapy. 5. Study design: This study is a multi-center, randomized and controlled clinical trial with two equally sized treatment groups: losartan/hydrochlorothiazide single-pill fixed combination and amlodipine/hydrochlorothiazide. 6. Study population: Men and Women aged over 18 years (n=180) meeting the inclusion/exclusion criteria. 7. Randomization and treatment: Patients should receive a 24-hour ambulatory blood pressure monitoring measurement before randomization. After stratification by centers, eligible patients will be randomly divided into two groups, taking losartan 100 mg/hydrochlorothiazide 25 mg fixed combination once a day or amlodipine besylate tablets (5 mg/tablet) + hydrochlorothiazide tablets (25 mg/tablet) once a day. 8. Follow up: 8 weeks. 9. Sample size: a total of 180 patients should be enrolled in the combination. 10. Timeline: After obtaining the approval of Ethics Committee of Ruijin Hospital in September 2018, recruitment will start. Patients enrollmen