Comparative Efficacy and Safety of Olmesartan Versus Losartan in Patients With Hypertension

Angiotensin II receptor blockers (ARBs) are the newest class of approved antihypertensive agents and the second class of drugs to exert their primary antihypertensive action by interrupting the renin-angiotensin system.It was a multicenter, randomized, double-blind trial in which efficacy of Olmesartan (20mg once a day) and losartan (50mg once a day) was compared in patients with hypertension.In patients with a cuff diastolic blood pressure (DBP) of ≥100 and ≥115 mm Hg and a mean daytime DBP of ≥90mm Hg and <120mm Hg, as measured by ambulatory blood pressure monitoring.Cuff and ambulatory blood pressures were monitored at baseline and after 8 weeks of treatment.All groups were adults and approximately 62% male, and their mean age was approximately 52 years.In all groups, mean baseline DBP and systolic blood pressure (SBP) were approximately 104 and 157mm Hg, respectively.The reduction of sitting cuff DBP with olmesartan (13.5mmHg), the primary efficacy variable of this study, was significantly greater than with losartan, enalapril, and quinapril (8.2, 7.9, and 9.9mm Hg, respectively).Reductions of cuff SBP with the four ARBs ranged from 8.4-13.3mmHg and were not significantly different.The reduction in mean 24-hour DBP with olmesartan (8.5mm Hg) was significantly greater than reductions with losartan and enalapril (6.2 and 5.6mm Hg, respectively) and showed a trend toward significance when compared to the reduction in DBP with quinapril (7.4mm Hg; p=0.087).The reduction in mean 24-hour SBP with olmesartan (12.5mmHg) was significantly greater than the reductions with losartan and enalapril (9.0 and 8.1mm Hg, respectively) and equivalent to the reduction with quinapril (11.3mmHg).All drugs were well tolerated.The authors conclude that olmesartan, at its starting dose, is more effective than the starting doses of the other tested drugs in reducing cuff DBP in patients with essential hypertension.