The risks and benefits of initial irbesartan/hydrochlorothiazide combination therapy in patients with severe hypertension

Abstract

The impact of delays in blood pressure (BP) reduction is particularly relevant for patients with severe hypertension who are at risk for hypertensive emergencies. Combination therapies may hold promise as initial treatment for these patients. The safety and efficacy of initial irbesartan / hydrochlorothiazide (angiotensin receptor blocker / thiazide) treatment was compared with that of irbesartan as monotherapy in a multicenter, double-blind, parallel-group study in patients with severe hypertension. After 5 weeks, 47% of patients receiving combination therapy achieved a target diastolic BP <90 mm Hg compared with 33% with monotherapy (P=.0005). Similarly, systolic BP/ diastolic BP <140 / 90 mm Hg targets were reached by more subjects treated with combination therapy than subjects receiving monotherapy (34.6% vs 19.2%, P<.0001). Initial use of combination therapy instead of monotherapy is estimated to prevent between 250 and 4500 cardiovascular events in every 100,000 severely hypertensive patients over 5 years, without significantly increasing serious adverse event rates.

Figure 1

Blood pressure (BP) control in severely hypertensive patients after treatment with irbesartan or irbesartan/hydrochlorothiazide (HCTZ). Percentage of patients achieving (A) diastolic BP (DBP) <90 mm Hg; (B) systolic BP (SBP)/DBP <140/90 mm Hg after treatment with irbesartan or irbesartan/HCTZ. The primary efficacy endpoint was DBP <90 mm Hg at 5 weeks. Adapted with permission from Neutel et al.

Figure 2

Changes in blood pressure over time in severely hypertensive patients after treatment with irbesartan or irbesartan (IRB)/hydrochlorothiazide (HCTZ). Reproduced with permission from Neutel et al. SeSBP indicates seated systolic blood pressure; SeDBP seated diastolic blood pressure.

Figure 3

The proportion of patients with diastolic blood pressure (DBP) ≥110 mm Hg over time after treatment with irbesartan or irbesartan/hydrochlorothiazide (HCTZ).