Use of ambulatory blood pressure monitoring to compare antihypertensive efficacy and safety of two angiotensin II receptor antagonists, losartan and valsartan

The efficacy and safety of losartan and valsartan were evaluated in a multi center, double-blind, randomized trial in patients with mild to moderate es sential hypertension. Blood pressure responses to once-daily treatment with either losartan 50 mg (n = 93) or valsartan 80 mg (n = 94) for 6 weeks wer e assessed through measurements taken in the clinic and by 24-hour ambulato ry blood pressure monitoring (ABPM). Both drugs significantly reduced clini c sitting systolic (SiSBP) and diastolic blood pressure (SiDBP) at 2, 4, an d 6 weeks. Maximum reductions from baseline in SiSBP and SiDBP on 24-hour A BPM were also significant with the two treatments. The reduction in blood p ressure was more consistent across patients in the losartan group, as indic ated by a numerically smaller variability in change from baseline on all AB PM measures, which achieved significance at peak (P = .017) and during the day (P = .002). In addition, the numerically larger smoothness index with l osartan suggested a more homogeneous antihypertensive effect throughout the 24-hour dosing interval. The antihypertensive response rate was 54% with l osartan and 46% with valsartan. Three days after discontinuation of therapy , SiDBP remained below baseline in 73% of losartan and 63% of valsartan pat ients. Both agents were generally well tolerated. Losartan, but not valsart an, significantly decreased serum uric acid an average 0.4 mg/dL at week 6. In conclusion, once-daily losartan 50 mg and valsartan 80 mg had similar a ntihypertensive effects in patients with mild to moderate essential hyperte nsion. Losartan produced a more consistent blood pressure-lowering response and significantly lowered uric acid, suggesting potentially meaningful dif ferences between these two A II receptor antagonists.