Ambulatory Blood Pressure Comparison of the Anti-hypertensive Efficacy of Fixed Combinations of Irbesartan/hydrochlorothiazide and Losartan/hydrochlorothiazide in Patients with Mild-to-moderate Hypertension

This study examined whether the greater anti-hypertensive efficacy of irbesartan monotherapy over losartan monotherapy extends to the respective fixed-dose combinations with hydrochlorothiazide (HCTZ) in patients with mild-to-moderate hypertension. Patients were treated with either irbesartan 150 mg/HCTZ 12.5 mg or losartan 50 mg/HCTZ 12.5 mg over a 4-week period. Twenty-four hour daytime and night-time mean blood pressure (BP), BP load and duration of action were assessed using ambulatory BP monitoring. Both treatment regimens significantly reduced BP from baseline for all efficacy variables assessed. A significant difference was noted in adjusted mean changes from baseline in 24-h ambulatory diastolic BP with irbesartan/HCTZ versus losartan/HCTZ. Reduction in diastolic load was significantly greater with irbesartan/HCTZ than with losartan/HCTZ as was mean ambulatory systolic BP during the last 4 h of the dosing interval. Both regimens were well tolerated, with no significant differences in terms of adverse event profile observed. Irbesartan 150 mg/HCTZ 12.5 mg resulted in greater reductions in ambulatory BP than losartan 50 mg/HCTZ 12.5 mg.