Efficacy and Safety of a Fixed Combination of Irbesartan/Hydrochlorothiazide in Chinese Patients with Moderate to Severe Hypertension

BACKGROUND AND OBJECTIVES In a multi-center, single-arm, prospective study, we investigated the efficacy and safety of the fixed irbesartan/hydrochlorothiazide combination in Chinese patients with moderate to severe hypertension. METHODS Eligible patients were aged 18-75 years, with a blood pressure of 160-199 mmHg systolic or 100-119 mmHg diastolic during a 1-week wash-out phase off antihypertensive medication. The enrolled patients started antihypertensive treatment with irbesartan/hydrochlorothiazide 150 mg/12.5 mg once daily, with the possible addition of irbesartan 150 mg once daily and up-titration to irbesartan/hydrochlorothiazide 300 mg/25 mg once daily at 4 and 8 weeks of follow-up, respectively. The primary efficacy variable was the goal blood pressure-attaining rate at 12 weeks of follow-up (<140/90 mmHg, or <130/80 mmHg in patients with diabetes mellitus). RESULTS In the intention-to-treat analysis (n = 501) at 12 weeks of follow-up, the goal blood pressure-attaining rate was 57.3%, and the mean change in blood pressure from baseline was 27.8 mmHg [95% confidence interval (CI) 26.4-29.1 mmHg; p < 0.001] systolic and 13.5 mmHg (95% CI 12.6-14.4 mmHg; p < 0.001) diastolic. Similar findings were observed in the per-protocol analysis (n = 449). The prevalence of microalbuminuria and left ventricular hypertrophy significantly (p ≤ 0.01) decreased from 33.4% (150/449) and 50.4% (215/427) at baseline to 23.4% (105/447) and 41.3% (176/427) at the end of follow-up, respectively. Four patients (2.0%) reported a serious adverse event. CONCLUSION The fixed irbesartan/hydrochlorothiazide combination may control blood pressure to the target level in about 60% of Chinese patients with moderate to severe hypertension, with an acceptable safety profile.