Efficacy of initiating therapy with amlodipine and hydrochlorothiazide or their combination in hypertensive Nigerians.

In order to evaluate whether amlodipine or hydrochlorothiazide would be preferable to initiate therapy, 90 untreated hypertensive Nigerians of both genders aged 31-86 years with blood pressure >160/90 and ≤180/120 mm Hg were recruited into a randomized 48-week study. Patients, 30 each in amlodipine, hydrochlorothiazide, and amlodipine-hydrochlorothiazide groups, were treated, respectively, with amlodipine 5 mg for 6 weeks and the dose increased to 10 mg till week 12, after which hydrochlorothiazide 25 mg was added; hydrochlorothiazide 25 mg till week 6, after which amlodipine 5-10 mg was added; and amlodipine 5-10 mg + hydrochlorothiazide 25 mg. Body mass index, blood pressure, heart rate, and 24-hour urine volume were evaluated at baseline and at the end of weeks 1, 3, 6, 12, 24, 36, and 48. The primary efficacy variables were decreased in mean trough sitting diastolic and systolic blood pressure such that blood pressure <; 140/90 mm Hg was regarded as normalized. At week 48 in the amlodipine group, 27 patients versus 25 patients in the hydrochlorothiazide group had diastolic blood pressure <90 mm Hg (90% vs. 83.3%; P <.03). In the amlodipine group, 23 patients versus 20 patients in the hydrochlorothiazide group had blood pressure < 140/90 mm Hg (76.7% vs. 66.7%; P <.01). In the amlodipine-hydrochlorothiazide group, 27 patients (90%) and 15 patients (50%) had diastolic blood pressure <90 mm Hg and blood pressure <; 140/90 mm Hg, respectively. This study has demonstrated that a regimen of amlodipine to which hydrochlorothiazide is subsequently added provides superior efficacy on blood pressure control when compared with a regimen of hydrochlorothiazide to which amlodipine is subsequently added or with ab initio amlodipine-hydrochlorothiazide combination therapy.

RCT Entities:   Population Interventions Outcomes