Assessment of suitable antihypertensive therapies: Combination with high-dose amlodipine/irbesartan vs triple combination with amlodipine/irbesartan/indapamide (ASAHI-AI study).

Abstract

Angiotensin receptor blockers (ARBs) plus calcium channel blockers (CCBs) are a widely used combination therapy for hypertensive patients. In order to determine which combination was better as the next-step therapy for standard-dose combination of ARBs and CCBs, a combination with high-dose CCBs or a triple combination with diuretics, the authors conducted a prospective, randomized, open-label trial to determine which of the following combination is better as the next-step treatment: a combination with high-dose CCBs or a triple combination with diuretics. Hypertensive outpatients who did not achieve their target blood pressure (BP) with usual dosages of ARBs and amlodipine 5mg were randomly assigned to treatment with irbesartan 100mg/amlodipine 10mg (Group 1: n=48) or indapamide 1mg in addition to ARBs plus amlodipine 5mg (Group 2: n=46). The primary end point was changes in the systolic BP (SBP) and diastolic BP (DBP) after the 12-week treatment period, while secondary end points were changes in BP after the 24-week treatment period and laboratory values. At 12weeks, the SBP/DBP significantly decreased from 152.1/83.4mmHg to 131.5/76.1mmHg in Group 1 and 153.9/82.1mmHg to 132.7/75.9mmHg in Group 2. Although both groups produced a similar efficacy in reducing the SBP/DBP (-19.2/-9.2mmHg in Group 1 and -21.6/-8.8mmHg in Group 2; SBP P=.378, DBP P=.825), high-dose CCBs combined with ARBs controlled hypertension without elevation of serum uric acid. These results will provide new evidence for selecting optimal combination therapies for uncontrolled hypertensive patients.