Initial combination therapy with irbesartan/hydrochlorothiazide for hypertension: an analysis of the relationship between baseline blood pressure and the need for combination therapy

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.

Comprehensive overview: efficacy, tolerability, and cost-effectiveness of irbesartan

Background

Hypertension represents a major health problem, affecting more than one billion adults worldwide. Irbesartan, an angiotensin II receptor blocker, is considered to be a highly effective treatment in the management of hypertension. The purpose of this review is to evaluate the efficacy, safety and tolerability profile , and cost-effectiveness of treatment with irbesartan in hypertension.

Methods

A review of the literature was conducted using the electronic PubMed and Cochrane Library databases and the Health Economic Evaluations Database of search terms relating to irbesartan efficacy, tolerability, and cost-effectiveness, and the results were utilized.

Results

Findings from the present analysis show that irbesartan either as monotherapy or in combination with other antihypertensive agents can achieve significant reductions in blood pressure, both systolic and diastolic, compared with alternative treatment options. Irbesartan was also found to have a renoprotective effect independent of its blood pressure-lowering in patients with type 2 diabetes and nephropathy. Furthermore, irbesartan demonstrated an excellent safety and tolerability profile , with either lower or equal adverse events compared with placebo and other alternative treatments. In terms of economic analyses, compared with other antihypertensive therapy alternatives, irbesartan was found to be a preferred option, that is less costly and more effective.

Conclusion

The evidence indicates that treating patients with hypertension alone or with type 2 diabetes and nephropathy using irbesartan can control hypertension, prolong life, and reduce costs in relation to existing alternatives.

Safety and efficacy of aliskiren/amlodipine/hydrochlorothiazide triple combination in patients with moderate to severe hypertension: a 54-week, open-label study

Combination antihypertensive therapies are recommended to attain blood pressure (BP) targets especially in high-risk patients in whom rapid and pronounced BP control is essential. This 28- to 54-week, open-label, multicenter study evaluated the safety and efficacy of a triple combination, aliskiren with amlodipine and hydrochlorothiazide (HCTZ), in patients with moderate to severe hypertension. Following a washout period of up to 4 weeks, patients received aliskiren/HCTZ 300/12.5 mg for 1 week, followed by add-on amlodipine 5 mg for 1 week. Thereafter, the doses of amlodipine and HCTZ were doubled. The first 206 of 564 patients who completed 28 weeks of study continued for an additional 26 weeks. Safety was assessed by recording all adverse events. Efficacy variables included changes in BP from baseline to endpoint and BP control rate. Of 564 patients, 493 completed the study. Peripheral edema (9.4%), headache (5.7%), nasopharyngitis (4.1%), and bronchitis (3.7%) were reported frequently. Clinically significant reductions in mean sitting systolic BP/mean sitting diastolic BP from baseline (-34.2/-20.3 mm Hg and -37.3/-21.8 mm Hg at weeks 28 and 54, respectively) were observed. Corresponding BP control rates were 69.1% and 77.1%. The aliskiren/amlodipine/HCTZ combination in patients with moderate to severe hypertension was well tolerated and provided clinically significant BP reductions and effective BP control.

Effectiveness of initiating treatment with valsartan/hydrochlorothiazide in patients with stage-1 or stage-2 hypertension

This prospective, 6-week, multicenter, double-blind study examined the benefits of initiating treatment with combination valsartan/hydrochlorothiazide (HCTZ) compared with initial valsartan monotherapy for 648 patients with stage-1 or stage-2 hypertension (age=52.6±10 years; 54% male; baseline blood pressure (BP)=161/98 mm Hg, 32% stage 1). Patients were randomized to valsartan 80 mg (V-low), valsartan 160 mg (V-high) or valsartan/HCTZ 160/12.5 mg (V/HCTZ), and electively titrated after weeks 2 and 4 to the next dosage level (maximum dose valsartan/HCTZ 160/25 mg) if BP remained >140/90 mm Hg. At end of the study, patients initiated with V/HCTZ required less titration steps compared with the initial valsartan monotherapy groups (63 vs 86% required titration by study end, respectively) and reached the target BP goal of <140/90 mm Hg in a shorter period of time (2.8 weeks) (P<0.0001) vs V-low (4.3 weeks) and V-high (3.9 weeks). Initial combination therapy was also associated with higher BP control rates and greater reductions in both systolic and diastolic BP from baseline (63%, −27.7±13/–15.1±8 mm Hg) compared with V-low (46%, −21.2±13/−11.4±8 mm Hg, P<0.0001) or V-high (51%, −24.0±13/−12.0±10 mm Hg, P<0.01). Overall and drug-related AEs were mild to moderate and were similar between V/HCTZ (53.1 and 14.1%, respectively) and the two monotherapy groups, V-low (50.5 and 13.8%) and V-high (50.7 and 11.8%). In conclusion, initiating therapy with a combination of valsartan and low-dose HCTZ results in early, improved BP efficacy with similar tolerability as compared with starting treatment with a low or higher dose of valsartan for patients with stage-1 and stage-2 hypertension.

Significance of initial blood pressure and comorbidity for the efficacy of a fixed combination of an angiotensin receptor blocker and hydrochlorothiazide in clinical practice

Background:

Two-thirds of all patients with arterial hypertension need drug combinations to achieve blood pressure (BP) goals. Fixed combinations have high efficacy and result in high patient compliance. 300 mg irbesartan plus 25 mg hydrochlorothiazide (HCTZ) has been investigated only in clinical trials but not in daily practice.

Methods:

A multicenter, noninterventional, noncontrolled observational study with 8123 patients seen by 1604 physicians in daily practice. BP reduction (office measurements), co-morbid disease and tolerability were documented over a 6-month observational period.

Results:

At mean baseline BP of 161 ± 15/94 ± 10 mmHg, administering of fixed combination resulted in a substantial BP reduction averaging 28 ± 15/14 ± 10 mmHg (P < 0.001). Decrease of systolic BP ran parallel with increasing systolic baseline BP (Spearman’s Rho −0.731; P < 0.0001; diastolic BP vs diastolic baseline BP Rho 0.740; P < 0.0001), independent from patient characteristics (age, obesity, diabetes or nephropathy) but enhanced with short history of hypertension (P < 0.0001 vs long history), prior beta blockers (P = 0.001 vs prior angiotensin receptor blockers [ARBs]), prior calcium channel blockers (P = 0.046 vs prior ARBs) and no prior medication (P = 0.012 vs prior ARBs). High compliance (>98%) and low incidence of adverse events (0.66%) were documented.

Conclusions:

The fixed combination of 300 mg irbesartan with 25 mg HCTZ was efficacious and tolerable in an unselected patient population in primary care.

Fixed combination of irbesartan and hydrochlorothiazide in the management of hypertension

Approximately 25% of the adult population worldwide is hypertensive and thus at risk of cardiovascular morbidity and mortality. Despite the availability of many antihypertensive drugs, at least 50% of patients do not achieve blood pressure (BP) targets and thus remain at increased cardiovascular risk. Fixed-dose (FD) irbesartan/hydrochlorothiazide (HCTZ) is an antihypertensive combination therapy approved for the treatment of patients whose BP is not adequately controlled on monotherapy and for initial treatment of patients likely to need multiple drugs to achieve their BP goal. The efficacy and tolerability of FD irbesartan/HCTZ has been demonstrated in both patient populations in large multicenter studies. In patients failing antihypertensive monotherapy, FD irbesartan/HCTZ (150/12.5 mg) has been shown to be more effective than FD valsartan/HCTZ (80/12.5 mg) and at least comparable to FD losartan/HCTZ (50/12.5 mg). In patients with moderate or severe hypertension receiving FD irbesartan/HCTZ as initial therapy, this combination achieved more rapid BP reductions compared with irbesartan monotherapy and enabled a greater proportion of patients with severe hypertension to achieve their BP target. FD irbesartan/HCTZ is thus a valuable addition to the clinician’s armamentarium for the management of hypertension and should help more patients achieve their BP target.

Initial combination therapy for rapid and effective control of moderate and severe hypertension

Moderate (grade 2) and severe (grade 3) hypertension are important public health problems associated with high cardiovascular risk. Blood pressure (BP) control becomes more difficult to achieve as hypertension progresses. Therefore, early and effective treatment is essential to prevent hypertensive urgencies and emergencies and reduce cardiovascular risk. Currently, less than 50% of patients being treated for moderate or severe hypertension in the United States achieve their BP goal as recommended by treatment guidelines. This review examines the cardiovascular risk and physician inertia associated with moderate and severe hypertension, and concludes that increased use of initial combination therapy can overcome many of the barriers to effective BP control. Furthermore, initial combination therapy with a renin-angiotensin system (RAS) inhibitor and diuretic has the potential to rapidly and effectively reduce BP across a range of baseline BPs, with a comparable adverse event profile to monotherapy.