The antihypertensive efficacy of the combination of irbesartan and hydrochlorothiazide assessed by 24-hour ambulatory blood pressure monitoring. Irbesartan Multicenter Study Group

In a multicenter, double-blind, randomized trial, 178 patients with ambulatory diastolic blood pressure (BP) > or =85 mm Hg and seated diastolic BP (SeDBP) 95-110 mm Hg received either once-daily irbesartan 75 mg/hydrochlorothiazide (HCTZ) 12.5 mg, irbesartan 150 mg/HCTZ 12.5 mg, or placebo for 8 weeks to assess reductions in 24-hour ambulatory BP and office BP. Safety and tolerability of all treatment regimens were also evaluated. BP results and therapeutic response (trough SeDBP normalized to <90 mm Hg) were expressed as change from baseline to Week 8. Mean reductions in 24-hour ambulatory BP and office seated BP for irbesartan/HCTZ combinations were significantly greater compared with placebo (all, p<0.01). More patients were normalized with irbesartan/HCTZ (65%-69%) than placebo (24%, p<0.01). The frequency of adverse events was similar in all groups. Irbesartan/HCTZ given once-daily appears to be a well-tolerated, safe, and effective antihypertensive treatment.