BLOOD PRESSURE REDUCTION EFFICACY OF ANGIOTENSIN II RECEPTOR BLOCKER COMBINED WITH CALCIUM CHANNEL BLOCKER IS MORE SYNERGISTIC THAN WITH DIURETICS: 24-HOUR AMBULATORY BLOOD PRESSURE MONITORING

Abstract

Background: The optimal combination drug therapy for hypertension is not yet established. The aim of this study was to compare the effects between fixed dose calcium channel blocker and double dose diuretics when used in combination with angiotensin II receptor blocker (ARB) on 24-hour ambulatory blood pressure (BP).

Methods: In a prospective, randomized, double-blind trial, hypertensive patients were assigned to Losartan/Amlodipine (L/A, dose of 50 mg/5 mg) group or Losartan/Hydrochlorothiazide (L/H, dose of 50 mg/12.5 mg) group. The patients who failed to achieved BP goal after 4 weeks treatment were increased dose to 100 mg/5 mg (L/A group) and 100 mg/25 mg (L/H group) respectively. 24-hour ambulatory BP was measured at baseline and after 20 weeks treatment.

Results: Total 220 patients [mean age = 59.6 ± 12.3 years, men = 154 (70%)] were enrolled. After 4 weeks initial treatment, the averaged office systolic and diastolic BP showed no significant differences between groups and 38 (34.9%) subjects in L/A group and 51 (45.9%) in L/H group needed increase in drug dose (p < 0.001). After 20 weeks treatment, the office diastolic BP and 24-hour mean ambulatory systolic BP were significantly lower in L/A group. Also the reductions of office diastolic BP and 24-hour ambulatory systolic BP were significantly apparent in L/A group compared with L/H group. (Table)

Conclusion: Losartan combined with amlodipine showed favorable office and 24-hour ambulatory BP lowering efficacy even with fixed dose amlodipine compared with double dose hydrochlorothiazide. These findings suggest that calcium channel blocker is more synergistic than diuretics when used with ARB on office BP and 24-hour BP reduction.