The Efficacy and Safety of Low- and High- Dose Fixed Combinations of Irbesartan/Hydrochlorothiazide in Patients With Uncontrolled Systolic Blood Pressure on Monotherapy: The INCLUSIVE Trial

Efficacy of single-pill combination in uncontrolled essential hypertension: A systematic review and network meta-analysis

This study aimed to evaluate the efficacy of single-pill combination (SPC) antihypertensive drugs in patients with uncontrolled essential hypertension. Through Searching Pubmed, EMBASE, the Cochrane Library, and Web of Science collected only randomized controlled trials on the efficacy of single-pill combination antihypertensive drugs in people with uncontrolled essential hypertension. The search period is from the establishment of the database to July 2022. The methodological quality of the included studies was assessed using the Cochrane Risk of Bias Assessment, and statistical analyses were performed using Review Manage 5.3 and Stata 15.1 software. This review ultimately included 32 references involving 16 273 patients with uncontrolled essential hypertension. The results of the network meta-analysis showed that a total of 11 single-pill combination antihypertensive drugs were included, namely: Amlodipine/valsartan, Telmisartan/amlodipine, Losartan/HCTZ, Candesartan/HCTZ, Amlodipine/benazepril, Telmisartan/HCTZ, Valsartan/HCTZ, Irbesartan/amlodipine, Amlodipine/losartan, Irbesartan/HCTZ, and Perindopril/amlodipine. According to SUCRA, Irbesartan/amlodipine may rank first in reducing systolic blood pressure (SUCRA: 92.2%); Amlodipine/losartan may rank first in reducing diastolic blood pressure (SUCRA: 95.1%); Telmisartan/amlodipine may rank first in blood pressure control rates (SUCRA: 83.5%); Amlodipine/losartan probably ranks first in diastolic response rate (SUCRA: 84.5%). Based on Ranking Plot of the Network, we can conclude that single-pill combination antihypertensive drugs are superior to monotherapy, and ARB/CCB combination has better advantages than other SPC in terms of systolic blood pressure, diastolic blood pressure, blood pressure control rate, and diastolic response rate. However, due to the small number of some drug studies, the lack of relevant studies has led to not being included in this study, which may impact the results, and readers should interpret the results with caution.

Interaction and Compatibility Studies in the Development of Olmesartan Medoxomil and Hydrochlorothiazide Formulations under a Real Manufacturing Process

A drug–drug and drug–excipient interactions and compatibilities study was conducted for two fixed-dose combination (FDC) products containing olmesartan medoxomil (OLM)/hydrochlorothiazide (HCT) 20/12.5 mg and OLM/HCT 40/12.5 mg during their development including storage. The study consisted of the evaluation of samples retrieved during all stages of a real manufacturing process. Powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), thermogravimetry (TGA), Fourier transform infrared spectroscopy (FT-IR), and contact angle techniques were applied to the samples to determine interactions and incompatibilities. Dissolution tests and long-term stability studies were conducted to evaluate dosage form performance. Results showed weak solid–state interactions able to obtain a eutectic mixture of OLM and HCT while microcrystalline cellulose (MC) impacted the thermal stability of both drugs. Reliable dissolution and long-term stability tests confirmed that the interactions observed were not considered incompatibilities because they were not influenced by the performance of the final products.

A randomized titrate-to-target study comparing fixed-dose combinations of azilsartan medoxomil and chlorthalidone with olmesartan and hydrochlorothiazide in stage-2 systolic hypertension

Background:

Azilsartan medoxomil (AZL-M), an angiotensin II receptor blocker, has been developed in fixed-dose combinations (FDCs) with chlorthalidone (CTD).

Objective/methods:

We compared FDCs of AZL-M/CTD 20/12.5 mg once daily titrated to 40/25 mg if needed or AZL-M/CTD 40/12.5 mg once daily titrated to 80/25 mg if needed with an olmesartan medoxomil (OLM)-hydrochlorothiazide (HCTZ) 20/12.5 mg FDC once daily titrated to 40/25 mg if needed in a randomized, double-blind, 8-week study of 1085 participants with clinic SBP 160–190 mmHg and DBP 119 mmHg or less. Titration to higher doses occurred at week 4 if BP was at least 140/90 mmHg (≥130/80 mmHg if diabetes or chronic kidney disease). The primary endpoint was change from baseline in clinic SBP; 24-h ambulatory BP monitoring was also measured.

Results:

Greater reductions in clinic SBP from a baseline of 165 mmHg were observed (P < 0.001) in both AZL-M/CTD arms (−37.6 and −38.2 mmHg) versus OLM/HCTZ (−31.5 mmHg), despite greater dose titration in the OLM/HCTZ group. At 8 weeks, both AZL-M/CTD FDCs reduced 24-h SBP more than OLM/HCTZ (−26.4 and −27.9 versus −20.7 mmHg; both P < 0.001), and higher proportions in both AZL-M/CTD groups achieved target BP compared with the OLM/HCTZ group (69.4 and 68.9 versus 54.7%, both P < 0.001). Adverse events leading to drug discontinuation occurred in 6.2, 9.5, and 3.1% with the AZL-M/CTD lower and higher doses, and OLM/HCTZ, respectively.

Conclusion:

This large, titration-to-target BP study demonstrated AZL-M/CTD FDCs to have superior antihypertensive efficacy compared with the maximum approved dose of OLM/HCTZ.

Blood Pressure Response to Zofenopril or Irbesartan Each Combined with Hydrochlorothiazide in High-Risk Hypertensives Uncontrolled by Monotherapy: A Randomized, Double-Blind, Controlled, Parallel Group, Noninferiority Trial

In this randomized, double-blind, controlled, parallel group study (ZENITH), 434 essential hypertensives with additional cardiovascular risk factors, uncontrolled by a previous monotherapy, were treated for 18 weeks with zofenopril 30 or 60 mg plus hydrochlorothiazide (HCTZ) 12.5 mg or irbesartan 150 or 300 mg plus HCTZ. Rate of office blood pressure (BP) response (zofenopril: 68% versus irbesartan: 70%; p = 0.778) and 24-hour BP response (zofenopril: 85% versus irbesartan: 84%; p = 0.781) was similar between the two treatment groups. Cardiac and renal damage was equally reduced by both treatments, whereas the rate of carotid plaque regression was significantly larger with zofenopril. In conclusion, uncontrolled monotherapy treated hypertensives effectively respond to a combination of zofenopril or irbesartan plus a thiazide diuretic, in terms of either BP response or target organ damage progression.

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.

Which thiazide to choose as add-on therapy for hypertension?

Combined therapy is required in the majority of patients with hypertension to achieve blood pressure (BP) targets. Although different antihypertensive drugs can be combined, not all combinations are equally effective and safe. In this context, the combination of a renin angiotensin system inhibitor with a diuretic, usually a thiazide, particularly hydrochlorothiazide (HCTZ) or thiazide-like diuretics, such as chlorthalidone or indapamide, is recommended. However, not all diuretics are equal. Although HCTZ, chlorthalidone, and indapamide as add-on therapy effectively reduce BP levels, the majority of studies have obtained greater BP reductions with chlorthalidone or indapamide than with HCTZ. Moreover, there are data showing benefits with chlorthalidone or indapamide beyond BP. Thus, chlorthalidone seems to have pleiotropic effects beyond BP reduction. Moreover, compared with placebo, chlorthalidone has small effects on fasting glucose and total cholesterol, and compared with HCTZ, chlorthalidone achieves significantly lower total cholesterol and low-density lipoprotein cholesterol levels. Similarly, indapamide has demonstrated no negative impact on glucose or lipid metabolism. More importantly, although head-to-head clinical trials comparing the effects of indapamide or chlorthalidone with HCTZ are not available, indirect comparisons and post hoc analyses suggest that the use of chlorthalidone or indapamide is associated with a reduction in cardiovascular events. Despite this, the most frequent diuretic used in clinical practice as add-on therapy for hypertension is HCTZ. The purpose of this review is to update the published data on the efficacy and safety of HCTZ, chlorthalidone, and indapamide as add-on therapy in patients with hypertension.

Combining irbesartan and trichlormethiazide enhances blood pressure reduction via inhibition of sympathetic activity without adverse effects on metabolism in hypertensive rats with metabolic syndrome

Sympathoexcitation and oxidative stress in the brain have pivotal roles in hypertension with metabolic syndrome (MetS). Here, we examined whether oral administration of irbesartan (IRB) and trichlormethiazide (TCM) decreases blood pressure (BP) via inhibiting sympathetic activity through anti-oxidant effects in the brain of spontaneously hypertensive rats (SHR-cp). IRB/TCM treatment decreased BP more profoundly than IRB monotherapy. Urinary norepinephrine excretion and oxidative stress in the brain were decreased in both IRB and IRB/TCM groups without any adverse effect on the metabolic profile. These findings suggest that IRB/TCM profoundly decreases BP in SHR-cp by inhibiting sympathetic activity via anti-oxidant effects in the brain.

Zofenopril plus hydrochlorothiazide and irbesartan plus hydrochlorothiazide in previously treated and uncontrolled diabetic and non-diabetic essential hypertensive patients

INTRODUCTION

In most treated patients with hypertension, a two or more drug combination is required to achieve adequate blood pressure (BP) control. In our study we assessed whether the combination of zofenopril + hydrochlorothiazide (HCTZ) was at least as effective as irbesartan + HCTZ in essential hypertensives with at least one additional cardiovascular risk factor, uncontrolled by a previous monotherapy.

METHODS

After a 2-week placebo washout, 361 treated hypertensive patients [office sitting diastolic BP (DBP), ≥90 mmHg], aged 18-75 years, were randomized double blind to 18-week treatment with zofenopril 30 mg plus HCTZ 12.5 mg or irbesartan 150 mg plus HCTZ 12.5 mg once daily, in an international, multicenter study. After the first 6 and 12 weeks, zofenopril and irbesartan doses could be doubled in non-normalized subjects. The primary study end point was the office sitting DBP reduction after 18 weeks of treatment. Secondary end points included office systolic BP (SBP), ambulatory BP and high sensitivity C-reactive protein (hs-CRP).

RESULTS

The between-treatment difference for office DBP averaged to +1.0 (95% CI -0.4, +0.8) mmHg (P = 0.150), the upper limit of the 95% confidence interval being inferior to the protocol-defined non-inferiority limit (3 mmHg). In the subset of patients with valid ambulatory BP, no difference in 24-h average DBP [n = 181; 6.7 (8.7, 4.6) zofenopril + HCTZ vs. 6.3 (8.8, 3.7) mmHg irbesartan + HCTZ, P = 0.810] and SBP reductions [11.7 (15.4, 8.0) vs. 12.6 (17.2, 8.0) mmHg, P = 0.758] were observed between the two treatment groups. hs-CRP was reduced by zofenopril + HCTZ [-0.52 (-1.05, 0.01) mg/L], while it was increased by irbesartan plus HCTZ [0.97 (0.29, 1.65) mg/L, P = 0.001 between treatments].

CONCLUSION

In previously monotherapy-treated, uncontrolled patients with hypertension, zofenopril 30-60 mg + HCTZ 12.5 mg is as effective as irbesartan 150-300 mg plus HCTZ 12.5 mg, with the added value of a potential protective effect against vascular inflammation.

Release from glomerular overload by the addition of low-dose thiazide in patients with angiotensin receptor blocker-resistant hypertension

BACKGROUND/AIMS

This multicenter, prospective, observational study assessed the renoprotective effects of losartan/thiazide combination therapy in terms of lowering the estimated glomerular filtration rate (eGFR).

METHODS

Adult patients with angiotensin receptor blocker (ARB)-resistant essential hypertension (n = 104) were enrolled and switched to combination therapy with losartan (50 mg/day) and hydrochlorothiazide (12.5 mg/day).

RESULTS

eGFR values declined significantly during the first 3 months, and changes in eGFR were assessed according to tertiles of the eGFR decrease ratio at 3 months. Only the high eGFR decrease (1st tertile) group showed significantly greater decreases in baseline eGFR and albumin-to-creatinine ratio (ACR) during the first 3 months. Additionally, the assessment according to tertiles of the baseline eGFR showed a signifcant decrease in eGFR and ACR during the first 3 months in the high baseline eGFR (1st tertile) group, but not in the moderate (2nd tertile) and low baseline eGFR (3rd tertile) groups.

CONCLUSION

The present results revealed that losartan/thiazide combination therapy attenuated glomerular overload, indicating that this therapy may provide glomerular protection in patients with an elevated GFR without causing prolonged damage to renal function.

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.

Long-term efficacy of olmesartan medoxomil in Chinese hypertensive patients as assessed by clinic, ambulatory and home blood pressure measurements

Background and Objectives

There is limited information on the long-term efficacy and safety of olmesartan medoxomil in the management of hypertension in Chinese patients. We therefore conducted the present multicentre, single-arm, prospective, observational study to investigate the 24-week efficacy and safety of olmesartan medoxomil in patients with mild to moderate hypertension.

Methods

Eligible patients (diastolic blood pressure [BP] 90–109 mmHg and systolic BP <180 mmHg off antihypertensive medication) were started on olmesartan medoxomil 20 mg once daily, with the possible up-titration to 40 mg once daily during 24 weeks of follow-up, to control clinic BP to the target level (<140/90 and <130/80 mmHg in diabetes mellitus). In a subset of enrolled patients, 24-h ambulatory and home BP monitoring were also performed.

Results

In the intent-to-treat analysis (n = 348), at 24 weeks of follow-up, the mean ± SD changes from baseline in clinic systolic/diastolic BP were 21.2 ± 14.2/16.0 ± 8.8 mmHg (p < 0.001). The proportions of patients who achieved the goal BP for systolic, diastolic and both were 81, 80 and 75 %, respectively. Olmesartan medoxomil also significantly (p < 0.001) reduced systolic/diastolic BP measured at patients’ homes by 17.7 ± 13.1/12.1 ± 7.9 mmHg from baseline (n = 109), and reduced mean 24-h, daytime and night-time ambulatory BP by 13.3 ± 16.3/7.6 ± 9.5 mmHg, 13.9 ± 17.4/8.0 ± 10.4 mmHg and 12.3 ± 18.1/6.8 ± 10.2 mmHg, respectively (n = 87). Seven (2.0 %) serious adverse events were reported during follow-up.

Conclusion

In Chinese hypertensive patients, olmesartan medoxomil is efficacious in lowering BP as assessed by three different BP-measuring methods and has an acceptable long-term safety and tolerability profile.

Azilsartan Medoxomil Plus Chlorthalidone Reduces Blood Pressure More Effectively Than Olmesartan Plus Hydrochlorothiazide in Stage 2 Systolic Hypertension

Azilsartan medoxomil, an effective, long-acting angiotensin II receptor blocker, is a new treatment for hypertension that is also being developed in fixed-dose combinations with chlorthalidone, a potent, long-acting thiazide-like diuretic. We compared once-daily fixed-dose combinations of azilsartan medoxomil/chlorthalidone force titrated to a high dose of either 40/25 mg or 80/25 mg with a fixed-dose combination of the angiotensin II receptor blocker olmesartan medoxomil plus the thiazide diuretic hydrochlorothiazide force titrated to 40/25 mg. The design was a randomized, 3-arm, double-blind, 12-week study of 1071 participants with baseline clinic systolic blood pressure 160 to 190 mm Hg and diastolic blood pressure ≤119 mm Hg. Patients had a mean age of 57 years; 59% were men, 73% were white, and 22% were black. At baseline, mean clinic blood pressure was 165/96 mm Hg and 24-hour mean blood pressure was 150/88 mm Hg. Changes in clinic (primary end point) and ambulatory systolic blood pressures at week 12 were significantly greater in both azilsartan medoxomil/chlorthalidone arms than in the olmesartan/hydrochlorothiazide arm ( P <0.001). Changes in clinic systolic blood pressure (mean±SE) were −42.5±0.8, −44.0±0.8, and −37.1±0.8 mm Hg, respectively. Changes in 24-hour ambulatory systolic blood pressure were −33.9±0.8, −36.3±0.8, and −27.5±0.8 mm Hg, respectively. Adverse events leading to permanent drug discontinuation occurred in 7.9%, 14.5%, and 7.1% of the groups given azilsartan medoxomil/chlorthalidone 40/25 mg, azilsartan medoxomil/chlorthalidone 80/25 mg, and olmesartan/hydrochlorothiazide 40/25 mg, respectively. This large, forced-titration study has demonstrated superior antihypertensive efficacy of azilsartan medoxomil/chlorthalidone fixed-dose combinations compared with the maximum approved dose of olmesartan/hydrochlorothiazide.

Single-pill telmisartan and amlodipine: a rational combination for the treatment of hypertension

Despite the well documented benefits conferred by adequate control of hypertension, the majority of hypertensive patients display suboptimal control and few patients achieve blood pressure (BP) levels <140/90 mmHg. As a consequence, combination therapy will be required in the majority of patients to achieve target BP. Fixed-dose combinations of antihypertensives not only simplify treatment regimens, contributing to enhanced patient adherence, they provide superior BP-lowering efficacy and an improved tolerability profile. Fixed-dose combinations have become the strategy of choice in high-risk patients or those with stage 2-3 hypertension. The combination of a renin-angiotensin system inhibitor (RASI) with a calcium channel blocker (CCB) is a first-line combination that, in addition to its antihypertensive efficacy, reduces oedema, the main adverse effect of the dihydropyridine CCB and the main factor limiting their use. In morbidity/mortality studies, this fixed-dose combination has also demonstrated superiority over a RASI combined with a diuretic. The single-pill combination of telmisartan and amlodipine has been shown to produce a dose-dependent BP-lowering effect significantly greater than that of either agent administered as monotherapy. These findings have been confirmed by ambulatory BP monitoring in patients with stage 1 and 2 hypertension, which demonstrated that single-pill telmisartan/amlodipine provides substantial 24-hour BP-lowering efficacy. A higher proportion of patients achieved 24-hour BP goals of <130/80 mm Hg on combination therapy. The superior efficacy of combination therapy has been demonstrated across a broad range of patients, including those with moderate-to-severe hypertension, diabetes mellitus and obesity. Moreover, combined use of telmisartan and amlodipine reduces the incidence of amlodipine-induced oedema, making it a preferred combination for the treatment of hypertension.

Efficacy and safety of early versus late titration of fixed-dose irbesartan/hydrochlorothiazide: ACTUAL study

Hypertension management guidelines recommend titrating antihypertensive drugs stepwise every 4-6 weeks.We compared efficacy and safety of early versus late titration after 10 weeks' treatment with irbesartan/hydrochlorothiazide. Hypertensive patients uncontrolled on monotherapy were randomized into two groups. In the early titration group (E), patients received irbesartan/hydrochlorothiazide 150/12.5 mg for 2 weeks; uncontrolled patients were up-titrated to 300/25 mg at weeks 2 and 6. In the late titration group (L), patients received 150/12.5 mg for 6 weeks; uncontrolled patients were up-titrated to 300/25 mg at week 6 (W6). The change of mean systolic (SBP) and diastolic blood pressure (DBP) from baseline to week 10 (W10) were studied using a covariance analysis model. The percentage of controlled patients at W10 was compared between groups using Fisher's exact test. Of 833 patients enrolled from 14 countries, the intent-to-treat (ITT) population included 795 (mean age 58 +/- 12 years, female 60%, obesity 38%, diabetes 22%). AtW6, mean SBP decrease was: E - 28.8 mmHg vs L - 26.3 mmHg (p = 0.02). At W10, there was similar mean SBP decrease: E - 29.5 mmHg vs L- 31.0 mmHg (p = 0.14). The control rate at W10 was 58% (E) and 64% (L), p = 0.06. Serious adverse events were more frequent in E (2.5% vs 0.7%, p= 0.044). Both early and late titration regimens provide similar BP decrease and control rate.

A comparison of the efficacy and safety of irbesartan/hydrochlorothiazide combination therapy with irbesartan monotherapy in the treatment of moderate or severe hypertension in diabetic and obese hypertensive patients: a post-hoc analysis review

Hypertension is difficult to treat in patients with type 2 diabetes mellitus (T2DM) or obesity. Combination therapies are often required to effectively lower blood pressure (BP) and attain BP goals. In this post-hoc analysis of 2 prospective, randomized, controlled studies in patients with uncontrolled or untreated moderate or severe hypertension, the efficacy and safety of treatment with irbesartan/hydrochlorothiazide (HCTZ) and irbesartan was assessed in 2 separate analyses: patients with diabetes (n=143) and by obesity status (n=1125). Patients received irbesartan/HCTZ (150 mg/12.5 mg titrated to 300 mg/25 mg) or irbesartan (150 mg titrated to 300 mg) for 7 (severe hypertension study) or 12 (moderate hypertension study) weeks. Efficacy comparisons between treatment groups were performed using Fisher's exact tests. After 7 to 8 weeks of treatment, systolic BP (SBP)/diastolic BP (DBP) decreased in patients with diabetes by 26.9/17.8 mm Hg and 21.8/15.8 mm Hg after irbesartan/HCTZ and irbesartan treatment, respectively (P [SBP]=0.09, P [DBP]=0.27). In obese patients (n=544), SBP/DBP decreased by 29.4/20.2 mm Hg and 20.1/15.9 mm Hg after irbesartan/HCTZ and irbesartan treatment, respectively (P<0.0001). More patients with T2DM reached the BP goal of <130/80 mm Hg at week 7 to 8 in the irbesartan/HCTZ group than in the irbesartan group (12% vs 5%), although not statistically significant (P=0.22). Significantly more obese patients reached their respective BP goals in the irbesartan/HCTZ group than in the irbesartan group (48% vs 23%; P<0.0001). Treatment-emergent adverse event rates were similar between treatment groups regardless of the presence of diabetes or body mass index (BMI) status. In patients with moderate or severe hypertension and with a BMI ≥ 30 kg/m(2), initial treatment with irbesartan/HCTZ combination therapy was more effective than irbesartan monotherapy.

Cardiovascular protection by initial and subsequent combination of antihypertensive drugs in daily life practice

Guidelines recommend a combination of 2 drugs to be used as first-step treatment strategy in high-risk hypertensive individuals to achieve timely blood pressure control and avoid early events. The evidence that this is associated with cardiovascular (CV) benefits compared with initial monotherapy is limited, however. The objective of this study was to assess whether, compared with antihypertensive monotherapy, a combination of antihypertensive drugs provides a greater CV protection in daily clinical practice. A population-based, nested case-control study was carried out by including the cohort of 209 650 patients from Lombardy (Italy) aged 40 to 79 years who were newly treated with antihypertensive drugs between 2000 and 2001. Cases were the 10 688 patients who experienced a hospitalization for CV disease from initial prescription until 2007. Three controls were randomly selected for each case. Logistic regression was used to model the CV risk associated with starting on and/or continuing with combination therapy. A Monte-Carlo sensitivity analysis was performed to account for unmeasured confounders. Patients starting on combination therapy had an 11% CV risk reduction with respect to those starting on monotherapy (95% CI: 5% to 16%). Compared with patients who maintained monotherapy also during follow-up, those who started on combination therapy and kept it along the entire period of observation had 26% reduction of CV risk (95% CI: 15% to 35%). In daily life practice, a combination of antihypertensive drugs is associated with a great reduction of CV risk. The indication for using combination of blood pressure drugs should be broadened.

Economic evaluation of irbesartan in combination with hydrochlorothiazide in the treatment of hypertension in Greece

OBJECTIVES

Hypertension is a major risk factor for cardiovascular disease and a leading cause of morbidity and mortality. This study evaluates irbesartan in relation to commonly used alternative hypertension therapies losartan and valsartan given in combination with hydrochlorothiazide (HCTZ) in the general hypertensive population in Greece.

METHODS

A Markov model with eight states of health was constructed: hypertension, myocardial infarction (MI), post-MI, angina, stroke, poststroke, heart failure, and death. The model has an annual cycle and estimates mean quality-adjusted survival and treatment cost, which reflect the hypertension treatment and managing cardiovascular events. Risk functions were used to conduct extrapolations. Data on treatment effectiveness, quality of life (QOL) and epidemiology were obtained from published clinical trials and studies. The database of the main Greek National Social Insurance Institute (IKA) was analyzed to estimate the cost of events. The analysis was done from a payer perspective. All outcomes were discounted, and prices correspond to 2008.

RESULTS

The estimated patient cost per annum was stable angina euro 2,252, unstable angina euro 2,572, myocardial infarction euro 2,473, post-MI euro 1,677, stroke euro 12,233, poststroke euro 1,240, heart failure euro 2,655, coronary angiography euro 1,544, percutaneous transluminal coronary angioplasty euro 6,511, and coronary artery bypass graft surgery euro 11,514. For the baseline group (age 57 years, systolic blood pressure 147 mmHg, cholesterol 6.00 mmol/L, body mass index 29) of men with mild to moderate hypertension, for irbesartan, the total treatment cost was euro 15,146, for losartan euro 15,696 and for valsartan euro 15,613; the quality-adjusted life years (QALYs) were irbesartan 12.67, losartan 12.63 and valsartan 12.64. For the baseline group of women with mild to moderate hypertension, the total treatment cost was euro 12,945 for irbesartan, euro 13,424 for losartan and euro 13,379 for valsartan; QALYs were 14.29 for irbesartan, 14.27 for losartan and 14.27 for valsartan. For men with severe hypertension, for irbesartan and losartan, the total treatment cost was euro 18,679 and euro 21,488 and QALYs 12.47 and 12.37, respectively. For women, the total treatment cost was euro 16,202 and euro 19,099 and QALYs 14.16 and 14.09, respectively. Similar results were obtained in relation to other treatment groups in various sensitivity analysis scenarios.

CONCLUSIONS

Based on efficacy data from clinical trials and lower attainment costs in various hypertensive patient populations, irbesartan in combination with HCTZ compares favorably with losartan and valsartan in combination with HCTZ in the Greek setting.

Major inducing factors of hypertensive complications and the interventions required to reduce their prevalence: an epidemiological study of hypertension in a rural population in China

Background

The complications of hypertension cause severe health problems in rural areas in China. We (i) screened the major factors inducing hypertensive complications and provided intervention measures; and (ii) verified the efficacy of the New Rural Cooperative Medical Scheme (NRCMS; a medical insurance scheme for rural residents) for hypertension management.

Methods

A survey was conducted in the villages of Yunnan (an underdeveloped province in southwest China). The NRCMS was initiated there in 2005. Data were collected through questionnaires, physical examination, electrocardiography, as well as blood and urine tests. To detect factors inducing hypertension complications, a generalized estimating equations model was developed. Multivariable logistic regression was used to analyze influencing factors for hypertension control.

Results

Poor management of hypertension was observed in women. Being female, old, poorly educated, a smoker, ignorant of the dangerousness of hypertension, and having uncontrolled hypertension made patients more prone to hypertension complications. Combination therapy with ≥2 drugs helped control hypertension, but most rural patients disliked multidrug therapy because they considered it to be expensive and inconvenient. The NRCMS contributed little to reduce the prevalence of complications and improve control of hypertension.

Conclusions

The present study suggested that the NRCMS needs to be reformed to concentrate on early intervention in hypertension and to concentrate on women. To increase hypertension control in rural areas in China, compound products containing effective and inexpensive drugs (and not multidrug therapy) are needed.

Time to achieve blood pressure goal with a combination versus a conventional monotherapy approach in hypertensive patients with metabolic syndrome

The time to achieve a blood pressure (BP) goal < or =130/85 mmHg with a combination versus a conventional monotherapy approach was evaluated in 308 hypertensive patients with metabolic syndrome. They were randomized to valsartan (V) 8 mg/amlodipine (A) 5 mg combination or to V 160 mg monotherapy for 12 weeks and every 2 weeks, there was a titration in nonresponder patients: in the combination group V/A was progressively increased to V 160/A 5 mg; V160/A 7.5 mg; V160/A 10 mg; V 240/A 10 mg, and V 320/A 10 mg. In the monotherapy group, the regimen was progressively modified as following: V 240 mg; V 320 mg; V 320/A 5 mg; V 320/A 7.5 mg, and V 320/A 10 mg. The mean time to achieve the BP goal was shorter in patients randomized to combination therapy compared to those randomized to conventional monotherapy (4.7 +/- 2.7 weeks vs. 7.1 +/- 3.9 weeks, respectively, p < 0.001). The percentage of patients who achieved target BP in the combination approach group statistically exceeded that of the monotherapy treated one already after 2 weeks of treatment (30.5 vs. 14.9%, p < 0.01) and again after 4, 6, 8, and 10 weeks of treatment. Only at 12 weeks the percentage of normalized patients was similar in the two treatment groups (78.8% vs. 75.3%, ns). These results suggest that initial therapy with a V/A combination approach may be more quickly effective than a conventional sequential monotherapy approach in achieving target BP in hypertensive patients with metabolic syndrome.

Efficacy and safety of irbesartan/HCTZ in severe hypertension according to cardiometabolic factors

This post hoc analysis of a 7-week, randomized, double-blind trial evaluated the efficacy and safety of initial irbesartan/hydrochlorothiazide treatment in 468 patients with severe, uncontrolled, hypertension (diastolic blood pressure [DBP] > or =100 mm Hg) at high cardiovascular risk. Systolic blood pressure (SBP)/DBP reductions ranged from 28.0 to 42.9/22.9 to 27.2 mm Hg in patients with obesity, diabetes, baseline SBP > or =180 mm Hg, and in the elderly. Blood pressure control to <140/90 mm Hg in the age and obesity subgroups ranged from 32.1% to 39.2% while control to <130/80 mm Hg in patients with diabetes was 11.5%. After 1 week of therapy, 72.5% of patients no longer had SBP > or =180 mm Hg; by 7 weeks, 51.3% had SBP 140 to 159 mm Hg and 26.5% had SBP <140 mm Hg. Treatment was well tolerated regardless of the subgroup. No excess of prespecified events was noted. Thus, initial treatment with irbesartan/hydrochlorothiazide was rapidly effective in high-risk, difficult-to-treat, severely hypertensive patients.

Efficacy of amlodipine and olmesartan medoxomil in patients with hypertension: the AZOR Trial Evaluating Blood Pressure Reductions and Control (AZTEC) study

The aim of the present study was to use ambulatory blood pressure (BP) monitoring (ABPM) to determine the efficacy of a fixed-dose combination of amlodipine (AML) and olmesartan medoxomil (OM) over the 24-hour dosing interval. This 12-week, titrate-to-goal study was conducted in 185 patients with hypertension. Patients were initially treated with AML 5 mg/ day and uptitrated to AML/OM 5/20, 5/40, and 10/40 mg/day every 3 weeks if mean seated BP (SeBP) was ≥120/80 mmHg. The primary efficacy endpoint was the change from baseline in mean 24-hour systolic BP at week 12 as assessed by ABPM. At baseline, the mean 24-hour ambulatory BP (±standard deviation [SD]) was 144.8±11.1/85.7±7.9 mmHg. At week 12, the change from baseline in mean 24-hour ambulatory BP (±standard error of the mean [SEM]) was -21.4±0.8/-12.7±0.5 mmHg (p < 0.0001 versus baseline). At baseline, the mean SeBP (±SD) was 158.2±12.6/92.8±8.6 mmHg and at week 12, the mean SeBP change (±SEM) from baseline (last observation carried forward) was -24.1±1.1/-12.1±0.7 mmHg (p < 0.0001 versus baseline). Proportions of patients achieving mean 24-hour ambulatory BP prespecified study targets were 70.9% (<130/80 mmHg), 48.3% (<125/75 mmHg), and 40.7% (<120/80 mmHg). Cumulatively, 76.8% of patients uptitrated to AML/OM 10/40 mg/day attained an SeBP goal of <140/90 mmHg. The study drug was well tolerated with few adverse events (peripheral edema, 2.2%; dizziness, 1.1%). An AML/OM-based titration regimen effectively reduces BP in patients with hypertension.

Safety and tolerability of fixed-dose irbesartan/hydrochlorothiazide for rapid control of severe hypertension

This prospective, double-blind, multicenter trial compared the safety and tolerability of irbesartan/hydrochlorothiazide (HCTZ) fixed-dose combination therapy with irbesartan monotherapy in patients with severe hypertension (seated diastolic blood pressure (SeDBP) >or=110 mm Hg, mean BP 172/113 mm Hg at baseline). Patients were randomized 2:1 to 7 weeks' irbesartan/HCTZ 150/12.5 mg to 300/25 mg (n = 468) or irbesartan 150 mg to 300 mg (n = 227). The incidence of treatment-related adverse events (AEs) was similar with combination and monotherapy (11.3% and 10.1%), and most AEs were mild-to-moderate. The combined incidence of prespecified AEs was lower with irbesartan/HCTZ than with irbesartan (8.8% vs. 11.5%). There were no treatment-related serious AEs or deaths. At week 5, more patients achieved SeDBP < 90 mm Hg compared to irbesartan (47% vs. 33%; P = 0.0005). Despite more rapid and aggressive BP lowering, initial fixed-dose irbesartan/HCTZ demonstrated a comparable AE profile to irbesartan monotherapy in patients with severe hypertension.

Irbesartan/hydrochlorothiazide for the treatment of isolated systolic hypertension: a subgroup analysis of the INCLUSIVE trial

This post hoc analysis of the Irbesartan/Hydrochlorothiazide (HCTZ) Blood Pressure Reductions in Diverse Patient Populations (INCLUSIVE) trial evaluated the efficacy and safety of fixed-dose irbesartan/HCTZ in patients with isolated systolic hypertension. Adults with uncontrolled systolic blood pressure (SBP) (140-179 mm Hg; 130-179 mm Hg in type 2 diabetes) after 4 weeks or more of antihypertensive monotherapy once-daily treatment with placebo for 4-5 weeks, followed by HCTZ 12.5 mg for 2 weeks, irbesartan/HCTZ 150/12.5 mg for 8 weeks, and then irbesartan/HCTZ 300/25 mg for 8 weeks, in a prospective, multicenter, open-label, single-arm study. In patients with isolated systolic hypertension (n = 443) and the total study population (n = 736), irbesartan/HCTZ treatment for 16 weeks provided comparable mean blood pressure (BP) reductions from baseline (21.4/10.1 mm Hg vs 21.5/10.4 mm Hg; p < .001 vs baseline) and high SBP control rates (74% vs 77%). Patients with isolated systolic hypertension and concomitant type 2 diabetes experienced smaller BP reductions (17.9/8.7 mm Hg vs 22.9/10.7 mm Hg) and lower rates of SBP control (< 130 mm Hg, 47%) than those without diabetes (< 140 mm Hg, 87%). BP reductions from baseline and SBP control rates were similar across isolated systolic hypertension subgroups (> or = 65 vs < 65 years, sex, race, and metabolic syndrome status). Irbesartan/HCTZ was well tolerated, with drug-related adverse events (dizziness, < or = 3%; upper respiratory tract infection, < or = 2%) occurring with similar rates in the isolated systolic hypertension and total population. Fixed-dose irbesartan/HCTZ combination treatment provided effective and well-tolerated BP lowering in a diverse population of patients with isolated systolic hypertension.

Achieving blood pressure goals: should angiotensin II receptor blockers become first-line treatment in hypertension?

The benefits of blood pressure control on the risks of major cardiovascular events are well established. In clinical trials conducted in patients with mild-to-moderate hypertension, the angiotensin II receptor blocker (ARB) telmisartan has been shown to provide reduction of blood pressure throughout the 24-h dosing interval. Clinical trials have also demonstrated that ARBs are effective agents in reducing the risk of cardiovascular mortality, stroke, heart failure and new-onset atrial fibrillation. Recently, the ONgoing Telmisartan Alone and in combination with Ramipril Global Endpoint Trial (ONTARGET) study established that telmisartan reduces morbidity and mortality in a broad cross-section of patients at high risk for heart and vascular events, to an extent similar to that of the angiotensin-converting enzyme inhibitor ramipril. In addition, ONTARGET demonstrated that telmisartan is somewhat better tolerated than ramipril. Attributes such as effective blood pressure lowering, tolerability and convincing outcomes data mean that ARBs satisfy the requirements for first-line antihypertensive agents.

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

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.

Issues in blood pressure control and the potential role of single-pill combination therapies

Hypertension (HTN) is a major risk factor for cardiovascular mortality, yet only a small proportion of hypertensive individuals receive appropriate therapy and achieve target blood pressure (BP) values. Factors influencing the success of antihypertensive therapy include physicians' acceptance of guideline BP targets, the efficacy and tolerability of the drug regimen, and patient compliance and persistence with therapy. It is now well recognised that most hypertensive patients require at least two antihypertensive agents to achieve their target BP. However, complicated treatment regimens are a major contributory factor to poor patient compliance. The use of combination therapy for HTN offers a number of advantages over the use of monotherapy, including improved efficacy, as drug combinations with a synergistic mechanism of action can be used. This additive effect means that lower doses of the individual components can be used, which may translate into a decreased likelihood of adverse events. The use of single-pill combination therapy, in which two or more agents are combined in a single dosage form, offers all the benefits of free combination therapy (improved efficacy and tolerability over monotherapy) together with the added benefit of improved patient compliance because of the simplified treatment regimen. The use of single-pill combination therapy may also be associated with cost savings compared with the use of free combinations for reasons of cheaper drug costs, fewer physician visits and fewer hospitalisations for uncontrolled HTN and cardiovascular events. Thus, the use of single-pill combination therapy for HTN should help improve BP goal attainment through improved patient compliance, leading to reduced costs for cardiovascular-related 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.

Telmisartan/Hydrochlorothiazide: a review of its use as fixed-dose combinations in essential hypertension

Fixed-dose combinations of telmisartan and hydrochlorothiazide (HCTZ) [Micardis Plus, Micardis HCT, PritorPlus] are available in many countries for the treatment of patients with essential hypertension. Combining the angiotensin II receptor antagonist (angiotensin II receptor blocker [ARB]) telmisartan with the thiazide diuretic HCTZ provides antihypertensive therapy with complementary mechanisms of action. In the US and EU, telmisartan/HCTZ is approved for patients whose hypertension is not adequately controlled with telmisartan monotherapy; US labelling for the fixed-dose combination also includes inadequate control of blood pressure (BP) with HCTZ monotherapy.The antihypertensive efficacy of once-daily telmisartan/HCTZ has been demonstrated in several large, randomized trials in patients with stages 1 and 2 hypertension. The addition of HCTZ to telmisartan achieved significant reductions in BP in nonresponders to telmisartan monotherapy, and the antihypertensive efficacy of telmisartan/HCTZ was similar to or significantly greater than that of various comparator agents. Moreover, in studies that used ambulatory BP monitoring, telmisartan/HCTZ provided consistent 24-hour BP reductions throughout morning, daytime and night-time periods. The BP-lowering efficacy over the entire 24-hour dose administration interval is consistent with the pharmacokinetic profile of telmisartan, which has the longest elimination half-life among currently available ARBs and a unique chemical structure. Adverse events with telmisartan/HCTZ in clinical trials were typically mild and transient, and no unexpected events occurred that had not been previously reported with either telmisartan or HCTZ. Extensive tolerability data are available for telmisartan, in particular from the ONTARGET study, the largest clinical outcomes trial with an ARB. As such, fixed-dose combinations of telmisartan/HCTZ provide an effective, rational and generally well tolerated treatment option for the management of patients with hypertension.

Comparison of angiotensin II type 1 receptor antagonists in the treatment of essential hypertension

Hypertension is a major health problem worldwide, yet remains under-diagnosed and under-treated. Angiotensin II type 1 receptor antagonists (angiotensin receptor blockers [ARBs]) are highly effective at reducing blood pressure (BP), exhibit renoprotective properties and have placebo-like tolerability. However, it is unclear whether there are clinical differences in efficacy and tolerability between the available ARBs. A review of published, randomized, comparative clinical trials suggests that differences in BP-lowering efficacy and 24-hour BP control may exist between ARBs, although it appears that there is no evidence for important differences in tolerability between ARBs. Few studies have assessed attainment rates for important combined systolic BP (SBP)/diastolic BP (DBP) goals recommended in treatment guidelines. Likewise, few studies have directly compared more than two agents or ARB/hydrochlorothiazide fixed-dose combinations, and most ARBs have not been compared across their full recommended dosage ranges. Overall, there is insufficient weight of evidence to allow definitive conclusions to be drawn regarding the comparative efficacy of the available ARBs. However, newer ARBs (e.g. olmesartan medoxomil and telmisartan) appear to be more effective than older ARBs (e.g. losartan and valsartan) in reducing DBP and/or SBP in some trials. In addition, olmesartan medoxomil treatment regimens resulted in high BP control rates in several trials, but head-to-head trials with other ARBs are required to put these control rates into perspective, especially for SBP control with various agents. The purpose of this review is to present published data from ARB efficacy trials for a comparison of various efficacy parameters among the agents within this drug class.

Efficacy and safety of fixed combinations of irbesartan/hydrochlorothiazide in hypertensive women: the inclusive trial

OBJECTIVE

This post hoc analysis of the Irbesartan/Hydrochlorothiazide Blood Pressure Reductions in Diverse Patient Populations (INCLUSIVE) trial evaluated the efficacy and safety of irbesartan/hydrochlorothiazide (HCTZ) in a diverse population of hypertensive women.

METHODS

INCLUSIVE was a multicenter, prospective, open-label, single-arm trial. Adult subjects had uncontrolled systolic blood pressure (SBP 140-159 mm Hg; 130-159 mm Hg for those with type 2 diabetes mellitus [T2DM]) after > or =4 weeks of antihypertensive monotherapy. Treatment was sequential: placebo (4-5 weeks), HCTZ 12.5 mg (2 weeks), irbesartan/HCTZ 150/12.5 mg (8 weeks), and irbesartan/HCTZ 300/25 mg (8 weeks). Mean changes from baseline to treatment end in SBP and diastolic blood pressure (DBP), BP goal attainment, and safety were assessed.

RESULTS

Treatment with irbesartan/HCTZ was associated with significant mean reductions in BP (intent-to-treat population, n = 370; SBP/DBP: -22.9/-10.3 +/- 14.7/8.8 mm Hg). Improvements in SBP were observed in all subgroups (p < 0.001): Caucasian (n = 207) -23.5 +/- 13.5 mm Hg; African American (n = 93) -21.0 +/- 17.2 mm Hg; Hispanics/Latino (n = 66) -23.6 +/- 14.3 mm Hg; age <65 years (n = 281) -22.5 +/- 14.7 mm Hg; age > or =65 years (n = 89) -24.3 +/- 14.5 mm Hg; T2DM (n = 97) -19.0 +/- 15.1 mm Hg; and metabolic syndrome (n = 187) -22.1 +/- 14.6 mm Hg. Overall, 82% (95% confidence interval [CI] 78%-86%) of women achieved their SBP goal, 86% (95% CI 83%-90%) achieved their DBP goal, and 76% (95% CI 71%-80%) achieved their dual SBP/DBP goal. Treatments were well tolerated in all groups.

CONCLUSIONS

Irbesartan/HCTZ treatment was effective and well tolerated in a diverse population of women whose BP was previously uncontrolled on monotherapy.

Angiotensin receptor blockers: current status and future prospects

Angiotensin receptor blockers (ARBs), through their physiological blockade of the renin-angiotensin system, reduce morbidity and mortality associated with hypertension, heart failure, myocardial infarction, stroke, diabetic nephropathy, and chronic kidney disease. Among many attributes, excellent tolerability, and their ability to control hypertension for 24 hours with a positive effect on renal function position them as a useful choice for hypertension and related conditions. Because of the widespread actions of the renin-angiotensin system on critical tissues, treatment with ARBs may be beneficial in special populations. Ongoing and future studies will be needed to conclusively determine if ARBs also improve outcomes in patients with heart failure and preserved systolic function, atrial fibrillation, cognitive dysfunction, and kidney transplant recipients. Preliminary clinical data also suggest that combining ARBs and angiotensin-converting enzyme inhibitors may provide a more optimal blockade of the renin-angiotensin system and, therefore, may offer greater cardio- and nephroprotection. Future data will help delineate which ARBs and angiotensin-converting enzyme inhibitors are best combined and which patient populations might benefit from the dual blockade of the renin-angiotensin system.

Prescribing patterns in hypertension: the emerging role of fixed-dose combinations for attaining BP goals in hypertensive patients

BACKGROUND

The attainment of clinical blood pressure (BP) goals can markedly reduce cardiovascular morbidity and mortality, yet approximately two-thirds of treated hypertensive patients in the United States have uncontrolled BP. Consequently, more aggressive management of hypertension, frequently involving combination therapy (e.g., fixed-dose combination [FDC] therapy), is needed to achieve the recommended BP goals of <140/90 mmHg for most patients, and <130/80 mmHg for high-risk patients.

SCOPE

This article, based on data from an extensive Medline search ('hypertension' AND 'prescribe', 'prescribing' OR 'prescription', date range: 1995-2007), focuses on prescribing patterns for antihypertensive medication, and on the emerging role of combination therapy, specifically FDC therapy, in treating hypertensive patients to target BP levels.

FINDINGS

Although the use of antihypertensive combination therapy has increased substantially in US adults over the last 20 years, such therapy remains considerably underutilized. Numerous studies have shown that combination therapies, including FDCs, can markedly reduce BP and adverse events relative to monotherapies, and this paper overviews data for various combination therapies: angiotensin-receptor blocker (ARB) + diuretic; angiotensin-converting enzyme (ACE) inhibitor + diuretic; calcium-channel blocker (CCB) + ACE inhibitor; and CCB + ARB. Specifically, fixed-dose CCB/ARB combinations of amlodipine with losartan, valsartan, or olmesartan medoxomil have recently been developed, and combination therapy schedules of amlodipine plus one of these ARBs have shown greater BP-lowering efficacy compared with the constituent monotherapies. Furthermore, in two large studies in a total of >3000 patients, CCB + ARB combination therapy was associated with significantly lower incidences of headache and peripheral edema than CCB monotherapy.

CONCLUSION

Guidelines for hypertension management clearly support the greater use of multidrug therapy, especially in high-risk patients. FDCs (e.g., various emerging CCB/ARB combinations) are a valuable option for such high-risk patients, as these combinations offer the potential to reduce adverse events, increase compliance, lower treatment costs, and improve BP goal-attainment rates.

Cost-effectiveness of irbesartan/hydrochlorothiazide in patients with hypertension: an economic evaluation for Sweden

Irbesartan, an angiotensin-II inhibitor, has been shown to be an effective antihypertensive agent in clinical trials. The purpose of this study was to assess the cost-effectiveness of irbesartan in combination with hydrochlorothiazide (HCTZ) in Swedish health-care setting by predicting clinical events and life years based upon observed reductions in blood pressure in clinical trials. The cost-effectiveness of antihypertensive treatment with irbesartan compared with placebo and to other selected angiotensin-II inhibitors (losartan, valsartan, candesartan) in combination with HCTZ was estimated using a Markov model. The incidence of cardiovascular disease was obtained from the Swedish inpatient registry, whereas the risk reductions associated with antihypertensive therapy were taken from the medical literature. Costs for antihypertensive therapy and for treatment of cardiovascular events were included, and the health effects were measured in terms of quality-adjusted life years (QALYs). The study was conducted from a health-care payer perspective. For a 55-year-old male, irbesartan 150 mg/HCTZ 12.5 mg was a dominant strategy (better health effects at lower costs) when compared with losartan 50 mg/HCTZ 12.5 mg and valsartan 80 mg/HCTZ 12.5 mg, and the cost-effectiveness ratio compared with placebo was 3500 euros per QALY gained. In moderate-to-severe hypertension, irbesartan was cost-effective compared with losartan, whereas the results compared with candesartan were mixed. High-dose combination therapy of irbesartan was also found to be cost-effective compared with low-dose combination therapy. The results from the model indicate that irbesartan provides a cost-effective antihypertensive treatment strategy compared with both placebo, and to valsartan and losartan.

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.

Role of combination therapy in the treatment of hypertension: focus on valsartan plus amlodipine

Hypertension control is rare in clinical practice, particularly in high-risk patients. A large factor is therapeutic inertia deriving from poorly prescribed lifestyle changes, excess monotherapy use, and scarce on-treatment modifications. The use of drug combinations significantly improves blood pressure (BP) control; in particular, fixed combinations improve therapy without increasing daily pill intake, thereby favouring patient compliance and therapy continuation. The most widely used fixed combination is based on thiazide diuretics added to either angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptor blockers (ARBs). Several large-scale clinical trials have been conducted showing that these combinations are effective in lowering BP. However, thiazide diuretics can reduce the metabolic benefits derived from renin-angiotensin-aldosterone system (RAAS) inhibitors in high metabolic risk patients. In contrast, ACE inhibitors or ARBs combined with dihydropyridine calcium channel antagonists (DHPCAs) exert a marked antihypertensive effect without decreasing metabolic protection by RAAS blockade. In the recent JIKEI heart study, approximately 60% of patients affected by hypertension, heart failure, coronary heart disease or their combination in the valsartan arm were simultaneously treated with DHPCAs. Of note, a 39% reduction in the primary endpoint of combined morbidity and mortality was reported in the valsartan compared with the non-valsartan arm. Furthermore, in a recent multinational study, 83% of 3161 hypertensive patients treated with valsartan and the DHCPA amlodipine reported a concontrolled BP after 8 weeks of treatment. As expected, amlodipine did not negatively influence the metabolic profile of patients, thereby supporting the role of ARB+DHPCA combinations as effective and promising tools in hypertension treatment. In summary, the combination of ARBs with DHPCAs is an effective strategy in hypertension treatment through synergy between their antihypertensive and vascular protective actions, persistent metabolic benefits deriving from RAAS inhibition, and reduced incidence of side effects.

Efficacy and safety of fixed combinations of irbesartan/hydrochlorothiazide in older vs younger patients with hypertension uncontrolled with monotherapy

Subgroup analysis of the Irbesartan/Hydrochlorothiazide Blood Pressure Reductions in Diverse Patient Populations (INCLUSIVE) trial evaluated the efficacy and safety of irbesartan/hydrochlorothiazide (HCTZ) fixed combinations in patients aged 65 years or older with uncontrolled systolic blood pressure (SBP) after >or= 4 weeks of antihypertensive monotherapy. The INCLUSIVE trial was a prospective, open-label, single-arm trial carried out in 119 sites. Of 844 patients completing placebo treatment, 212 were aged 65 years or older. Participants received treatment with placebo (4-5 weeks), HCTZ 12.5 mg (2 weeks), irbesartan/HCTZ 150/12.5 mg (8 weeks), and then irbesartan/HCTZ 300/25 mg (8 weeks). From baseline to week 18 (n=184, intent-to-treat population), mean change in SBP was -23.0+/-13.3 mm Hg (P<.001) and diastolic BP (DBP) was -10.9+/-7.7 mm Hg (P<.001). Mean SBP/DBP at study end was 134.0+/-14.7/75.1+/-8.4 mm Hg, and SBP, DBP, and SBP/DBP goal was achieved in 73%, 96%, and 72% of patients, respectively. Irbesartan/HCTZ combination therapy allowed SBP goal attainment in 73% of patients aged 65 years or older whose hypertension was previously uncontrolled with antihypertensive monotherapy.

Predictors of blood pressure response to angiotensin receptor blocker/diuretic combination therapy: a secondary analysis of the irbesartan/hydrochlorothiazide blood pressure reductions in diverse patient populations (INCLUSIVE) study

The secondary analysis of the Irbesartan/Hydrochlorothiazide Blood Pressure Reductions in Diverse Patient Populations (INCLUSIVE) clinical trial investigated whether baseline demographic and clinical variables are predictive of different degrees of blood pressure reduction following an angiotensin II receptor blocker/diuretic treatment regimen. Irbesartan/hydrochlorothiazide and other angiotensin receptor blocker combinations with a diuretic have been shown to be effective in reducing systolic blood pressure in a diverse patient population previously uncontrolled on monotherapy. Ordinary least squares regression analysis was performed on the intent-to-treat population of the INCLUSIVE study to identify variables predictive of variations in blood pressure changes in response to irbesartan/hydrochlorothiazide combination therapy. Higher baseline systolic blood pressure, female sex, type 2 diabetes, and statin therapy were found to be predictive of additional blood pressure lowering with this combination. The impact of higher baseline systolic blood pressure and diabetic state on changes in systolic blood pressure were diminished in female patients compared with male patients. In conclusion, a significant correlation may exist between certain clinical/demographic characteristics and the extent of the therapeutic response with irbesartan/hydrochlorothiazide treatment.

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

Hypertension treatment guidelines recommend initiating 2-drug therapy whenever blood pressure (BP) is > or =20 mm Hg systolic or > or =10 mm Hg diastolic above goal. This post hoc pooled analysis of 2 multicenter, randomized, double-blind, active-controlled forced-titration studies in 1235 patients with moderate and severe hypertension examined how baseline BP levels relate to the need for combination therapy by comparing the antihypertensive efficacy and tolerability of once-daily fixed-dose irbesartan/hydrochlorothiazide (HCTZ) 300/25 mg compared with irbesartan 300-mg or HCTZ 25-mg monotherapies. In study 1, patients with severe hypertension (seated diastolic BP [SeDBP] > or =110 mm Hg) were treated for 7 weeks with irbesartan or irbesartan/HCTZ combination therapy, with forced-titration after week 1. In study 2, patients with moderate hypertension (seated systolic BP [SeSBP] 160-180 mm Hg or SeDBP 100-110 mm Hg) were treated for 12 weeks with irbesartan/HCTZ, irbesartan monotherapy, or HCTZ monotherapy, with forced-titration after week 2. The relationship between baseline BP and the likelihood of achieving BP goals (SeSBP <140 mm Hg or SeDBP <90 mm Hg; SeSBP <130 mm Hg or SeDBP <80 mm Hg) as well as the antihypertensive response was evaluated at week 7/8. The need for combination therapy increased with increasing baseline BP and lower BP goals across the range of BP levels studied, with a comparable adverse effect profile to monotherapy. These results suggest that the likelihood of achieving an early BP goal for a given BP severity should be considered when choosing initial combination therapy vs monotherapy.

BP goal achievement in patients with uncontrolled hypertension : results of the treat-to-target post-marketing survey with irbesartan

BACKGROUND AND OBJECTIVE

Despite the fact that high BP is a leading risk factor for cardiovascular morbidity and mortality, BP goals are achieved in less than 10-30% of hypertensive patients. Irbesartan alone or in combination with hydrochlorothiazide has been shown to control BP in >70% of hypertensive patients in clinical trials. We set out to investigate the role in clinical practice of irbesartan in improving BP in uncontrolled hypertensive patients with a particular focus on patients with the metabolic syndrome through analysis of data from a post-marketing surveillance study.

METHODS

A multicentre, prospective, post-marketing surveillance study was conducted over 9 months in 14 200 patients aged > or =18 years with previously uncontrolled hypertension (either receiving therapy or newly diagnosed), paying particular attention to a subgroup of patients receiving irbesartan/hydrochlorothiazide as first-line combination therapy. BP was measured by a sphygmomanometer. The main outcome measures were systolic BP (SBP) and diastolic BP (DBP) reduction, response rate (DBP reduction of > or =10mm Hg or to <90 mm Hg), and BP normalisation (SBP <140 and DBP <90 mm Hg) in patients treated with irbesartan alone or in combination with hydrochlorothiazide. Analyses per patient subgroup, previous medication and whether treatment was initiated by the treating physician as first-line combination therapy were conducted. The number and nature of adverse events were documented.

RESULTS

Use of irbesartan 300 mg/day as monotherapy in previously uncontrolled patients resulted in a significant reduction in SBP/DBP (-26.8/-13.3mm Hg, p < 0.0001), which was comparable to the subgroup of patients with the metabolic syndrome (-26.3/-13.0mm Hg, p < 0.0001 vs baseline). Combination therapy (irbesartan 300 mg/hydrochlorothiazide 12.5mg once daily) lowered BP by -27.9/-14.2mm Hg (p < 0.0001) in previously uncontrolled patients; again the subgroup of patients with the metabolic syndrome achieved a comparable BP reduction (-27.5/-14.1mm Hg, p < 0.0001 vs baseline). Overall, no linear dose-response relationship was observed. Use of irbesartan/hydrochlorothiazide as first-line combination therapy was effective (BP normalisation rates between 65.7% and 78.6%) and safe. The mean number of antihypertensive tablets taken was reduced and after a mean period of 9 months, 92% of patients were still taking irbesartan therapy.

CONCLUSION

The study demonstrates that treatment with an irbesartan-based regimen for 9 months results in a strong BP reduction and is feasible as first-line combination therapy. Similar BP reductions were observed in the subgroup of patients with the metabolic syndrome. Compliance with treatment is particularly good, with >90% of patients continuing with treatment after 9 months.

Maximising antihypertensive effects of angiotensin II receptor blockers with thiazide diuretic combination therapy: focus on irbesartan/hydrochlorothiazide

BACKGROUND

Evidence-based guidelines for the management of hypertension are now well established. Studies have shown that more than 60% of patients with hypertension will require two or more drugs to achieve current treatment targets.

DISCUSSION

Combination therapy is recommended as first-line treatment by the JNC-7 guidelines for patients with a blood pressure > 20 mmHg above the systolic goal or 10 mmHg above the diastolic goal, while the International Society of Hypertension in Blacks recommends combination therapy when BP exceeds targets by > 15/10 mmHg. Current European Society of Hypertension-European Society of Cardiology guidelines also recommend the use of low-dose combination therapy in the first-line setting. Furthermore, JNC-7 recommends that a thiazide-type diuretic should be part of initial first-line combination therapy. Thiazide/diuretic combinations are available for a variety of classes of antihypertensive, including ACE inhibitors, angiotensin receptor blockers (ARBs), beta blockers and centrally acting agents. This article focuses on clinical data investigating the combination of an ARB, irbesartan, with the diuretic, hydrochlorothiazide.

CONCLUSIONS

These data indicate that the ARB/HCTZ combination has greater potency and a similar side effect profile to ARB monotherapy and represents a highly effective approach for attaining goal BP levels using a therapeutic strategy that very effectively lowers BP, is well tolerated and minimises diuretic-induced metabolic effects.