A comparison of the effects of fixed dose vs. single-agent combinations on 24-h blood pressure variability.

In addition to high blood pressure (BP), BP variability has recently also been shown to increase cardiovascular events. The purpose of this study was to compare the effect of a fixed-dose combinations (FDCs) of valsartan/amlodipine and a valsartan- and amlodipine-free drug combination on 24-h BPV. A total of 85 patients aged 18 or older and with no exclusion criteria were enrolled; of the 85 patients, 43 used the FDCs valsartan/amlodipine (160/10 mg) and 42 used a free drug combination of valsartan 160 mg and amlodipine 10 mg. Twenty-four hour ambulatory BP monitoring (ABPM) was performed after office BP measurements. Mean hourly BP, all-day BP reduction, trough/peak (T/P) ratio and Smoothness Index (SI) were calculated from the 24-h ABPM data. These were calculated separately for all-day, daytime, nighttime and early morning periods. The hourly mean diastolic BP (DBP) at 0800 hours in the FDCs group was significantly higher compared with the free drug combination group in the 24-h BP chronogram (P=0.041). Decreases in the all-day, daytime, nighttime and early morning systolic BP (SBP) and DBP in patients using a free drug combination were significantly greater compared with the FDC group. The SI and T/P ratio of the all-day, daytime and nighttime systolic and diastolic were also significantly higher compared with the FDC group. In addition, nighttime DBP reduction and the SI of DBP were lower in the diabetic patients. A free drug combination of amlodipine and valsartan provides more effective and smooth SBP and DSP control compared with FDCs.