Long-term safety, tolerability and efficacy of combination therapy with aliskiren and amlodipine in patients with hypertension

Efficacy and safety of aliskiren combination therapy: a protocol for an umbrella review

INTRODUCTION

Efficacy of aliskiren combination therapy with other antihypertensive has been evaluated in the treatment of patients with hypertension in recent systematic reviews. However, most previous reviews only focused on one single health outcome or one setting, none of them made a full summary that assessed the impact of aliskiren combination treatment comprehensively. As such, this umbrella review based on systematic reviews and meta-analyses is aimed to synthesise the evidences on efficacy, safety and tolerability of aliskiren-based therapy for hypertension and related comorbid patients.

METHODS AND ANALYSIS

A comprehensive search of PubMed, EMBASE, Cochrane Library, CNKI published from inception to August 2020 will be conducted. The selected articles are systematic reviews which evaluated efficacy, safety and tolerability of aliskiren combination therapy. Two reviewers will screen eligible articles, extract data and evaluate quality independently. Any disputes will be resolved by discussion or the arbitration of a third person. The quality of reporting evidence will be assessed using the Assessment of Multiple Systematic Reviews V.2 tool tool. We will take a mixed-methods approach to synthesising the review literatures, reporting summary of findings tables and iteratively mapping the results.

ETHICS AND DISSEMINATION

Ethical approval is not required for the study, as we would only collect data from available published materials. This umbrella review will be also submitted to a peer-reviewed journal for publication after completion.

PROSPERO REGISTRATION NUMBER

CRD42020192131.

Renin Inhibition with Aliskiren: A Decade of Clinical Experience

The renin-angiotensin-aldosterone system (RAAS) plays a key role in the pathophysiology of arterial hypertension as well as in more complex mechanisms of cardiovascular and renal diseases. RAAS-blocking agents like angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers, have long been key components in the treatment of essential hypertension, heart failure, diabetic nephropathy, and chronic kidney disease, showing benefits well beyond blood pressure reduction. Renin blockade as the first step of the RAAS cascade finally became possible in 2007 with the approval of aliskiren, the first orally active direct renin inhibitor available for clinical use and the newest antihypertensive agent on the market. In the last decade, many clinical trials and meta-analyses have been conducted concerning the efficacy and safety of aliskiren in comparison to other antihypertensive agents, as well as the efficacy and potential clinical use of various combinations. Large trials with cardiovascular and renal endpoints attempted to show potential benefits of aliskiren beyond blood pressure lowering, as well as morbidity and mortality outcomes in specific populations such as diabetics, heart failure patients, and post-myocardial infarction individuals. The purpose of this review is to present the currently available data regarding established and future potential clinical uses of aliskiren.

The impact of age on the benefits and risks of aliskiren treatment: analyses of the 3A registry

We aimed to analyze benefits and risks of aliskiren treatment in older adults (⩾ 65 years) in clinical practice. Patients (n = 14,986) were assigned to either aliskiren (ALIS), an angiotensin-converting-enzyme inhibitor or angiotensin receptor blocker (ACEi/ARB), or an agent not blocking the renin-angiotensin system (non-RAS). Older adults (n = 7396) had a longer history of hypertension (8.7 vs 4.7 years; P < 0.0001), lower mean diastolic blood pressure (DBP; 87.7 ± 11.0 vs 92.1 ± 11.0 mm Hg) and more renal (12.0 vs 5.6%; P < 0.0001) or cardiovascular disease (44.0 vs 18.9%; P < 0.0001); 4548 received aliskiren (68.8%), 1215 ACEi/ARBs (18.4%) and 850 non-RAS treatments (12.9%). Office BP at 1 year was reduced by 18.4 ± 21.5/7.2 ± 12.0 mm Hg. BP reductions were greater (19.5 ± 21.7/7.6 ± 12.1 mm Hg) in the aliskiren group than in the ACEi/ARB (15.6 ± 20.9/6.4 ± 11.9) and non-RAS groups (16.1 ± 20.7/6.5 ± 11.7 mm Hg), respectively (P<0.0001 for systolic BP (SBP) and <0.01 for DBP). After multivariable adjustment, differences in SBP reductions were clinically irrelevant and no differences were noted for DBP. Adverse effects were higher in older adults with no differences between treatment groups. In conclusion, the present analysis of a large, unselected cohort of patients in clinical practice from the 3A study, offers real-life evidence of the effectiveness and safety of aliskiren for the treatment of hypertension in older adults.

Renin inhibitors and cardiovascular and renal protection: an endless quest?

Renin-angiotensin system (RAS) blockade with angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) has become a major therapeutic approach in medicine since the end of the 1970's. Although these molecules were the first RAS blockers to be developed, it would have been physiologically and pharmacologically more pertinent to selectively inhibit renin itself. Indeed, the reaction between renin and its unique substrate, angiotensinogen, is the highly regulated and rate-limiting step of the RAS. The development of direct renin inhibitors (DRI) has been a slow and complex process and the synthesis of the first orally active DRI, aliskiren, was only achieved in the 2000's. Its pharmacological profile in patients with hypertension, diabetic nephropathy or heart failure, in addition to experimental evidence, suggests that aliskiren may be of value for the management of cardiovascular and renal diseases. However, the long-term, randomized, placebo-controlled, morbidity/mortality trial, ALTITUDE, which included 8,600 patients with type 2 diabetes, proteinuria and a high cardiovascular risk already treated with ACE inhibitors or ARBs was terminated in December 2011 because of futility and an increased incidence of serious adverse events in the aliskiren 300 mg arm. Other long-term studies are still ongoing to demonstrate the safety and efficacy of aliskiren to reduce cardiovascular morbidity and mortality in patients with heart failure and in elderly individuals (≥65 years) with systolic blood pressure of 130 to 159 mmHg, no overt cardiovascular disease, and a high cardiovascular risk profile. In the meantime, according to the European Medicines Agency recommendations, aliskiren should not be prescribed to diabetic patients in combination with ACE inhibitors or ARBs.

Aliskiren and amlodipine in the management of essential hypertension: meta-analysis of randomized controlled trials

Background

Aliskiren is a novel renin-angiotensin aldosterone system (RAAS) inhibitor, the combination therapy of aliskiren and amlodipine for blood pressure control have been reported recently. The primary objective of this analysis is to review recently reported randomized controlled trials (RCTs) to compare antihypertensive effects and adverse events between mono (amlodipine or aliskiren alone) and combination therapy of both medicines.

Methods

Databases for the search included Pubmed, Embase and the Cochrane Central Register of Controlled Trials. Revman v5.0 statistical program was used to analyze the data. Weighted mean differences (WMD) with a 95% confidence interval (CI) were used for the calculation of continuous data, and relative risk (RR) with a 95% CI was used for dichotomous data.

Results

We analyzed the data from 7 RCTs for a total of 6074 participants in this meta-analysis. We found that the aliskiren/amlodipine combination therapy had a stronger effect in lowering blood pressure as compared with the monotherapy using aliskiren (SBP: WMD = −10.42, 95% CI −13.03∼−7.82, P<0.00001; DBP: WMD = −6.60, 95% CI −7.22∼−5.97, P<0.00001) or amlodipine (SBP: WMD = −4.85, 95% CI −6.88∼−2.81, P<0.00001; DBP: WMD = −2.91, 95% CI −3.85∼−1.97, P<0.00001). No differences were found in terms of adverse events between combination therapy and monotherapy, except for the rates of peripheral edema and hypokalaemia which were significantly lower in the combination therapy than in the amlodipine monotherapy (RR = 0.78, 0.66∼0.92, P = 0.004; RR = 0.51, 0.27∼0.97, P = 0.04). Similar antihypertensive effects were found in both obese (body mass index > = 30 kg/m²) hypertensive and non-obese (body mass index <30 kg/m²) hypertensive patients. Moreover, there was no difference with the blood pressure lowering or adverse effects with regards to the combination therapy in both subgroups.

Conclusion

We found that aliskiren/amlodipine combination therapy provided a more effective blood pressure reduction than monotherapy with either drug without increase in the occurrence of adverse events.

Optimizing combination therapy in the management of hypertension: the role of the aliskiren, amlodipine, and hydrochlorothiazide fixed combination

High blood pressure is the leading risk factor for death and disability worldwide, and the prevalence is increasing. Effective treatment decreases the risk of adverse events in proportion to blood pressure reduction. Combination antihypertensive therapy reduces blood pressure promptly and effectively. Single-pill combinations reduce the pill burden and improve adherence, efficacy, and tolerability of treatment compared with single drug pills. A significant portion of the hypertensive population will require three drugs for adequate control. The single-pill combination of aliskiren, amlodipine, and hydrochlorothiazide is based on complementary mechanisms of action. Clinical trials have shown it to be a safe and effective treatment for hypertension. This combination is a reasonable choice in clinical practice for patients with hypertension that requires three drugs for effective treatment.

Clinic and ambulatory blood pressure lowering effect of aliskiren/amlodipine/hydrochlorothiazide combination in patients with moderate-to-severe hypertension: a randomized active-controlled trial

OBJECTIVES

To evaluate the clinic and ambulatory blood pressure (BP)-lowering efficacy and safety of an aliskiren/amlodipine/hydrochlorothiazide (HCT) triple combination compared with the component dual combinations, in patients with moderate-to-severe hypertension.

METHODS

This 8-week, double-blind, randomized, active-controlled study, after 1-4 weeks single-blind placebo run-in period, randomized 1191 patients to receive once-daily aliskiren/amlodipine 150/5 mg (n = 287), aliskiren/HCT 150/12.5 mg (n = 298), amlodipine/HCT 5/12.5 mg (n = 296), or aliskiren/amlodipine/HCT 150/5/12.5 mg (up-titrated from aliskiren/HCT 150/12.5 mg after initial 3 days) (n = 310) for 4 weeks, followed by forced titration to double the initial dose for the next 4 weeks.

RESULTS

Baseline mean sitting SBP and DBP (msSBP/msDBP) was comparable among treatment groups. The aliskiren/amlodipine/HCT combination resulted in significant least squares mean reduction in msSBP/msDBP from baseline to endpoints (week 4, -30.7/-15.9  mmHg; week 8, -37.9/-20.6  mmHg), superior (P < 0.001) to each of the dual combinations. The triple combination was associated with -27.8  mmHg reduction in msSBP at week 2, significantly better than the dual combinations (P < 0.05). Significantly greater mean SBP/DBP-lowering effect for triple vs. dual combinations was also demonstrated through 24-h, daytime, and night-time ambulatory BP measurements. Significantly greater (P < 0.001) BP control (msSBP/msDBP < 140/90  mmHg) was achieved with triple combination in patients with moderate-to-severe (62.3%) and severe (57.5%) hypertension.

CONCLUSION

Aliskiren/amlodipine/HCT at 150/5/12.5 mg (week 4) and 300/10/25 mg (week 8) provided statistically superior reductions in msSBP/msDBP and greater BP control rates vs. the dual combinations, and was well tolerated. The improved efficacy of BP reduction was evident within 2 weeks of initiating triple therapy even at low dose.

Safety and efficacy of aliskiren in the treatment of hypertension: a systematic overview

INTRODUCTION

Aliskiren is the first orally active direct renin inhibitor approved for the treatment of hypertension. Aliskiren's inhibitory effect on angiotensin I generation, through renin blockade, is highly specific and long-lasting (24 hours). This feature differentiates aliskiren from traditional antihypertensive drugs.

AREAS COVERED

This paper reviews the results of various clinical trials which investigate the safety and efficacy of aliskiren on blood pressure (BP) reduction and clinical end points.

EXPERT OPINION

Aliskiren is suitable for once-daily administration. Its antihypertensive effect is comparable or superior to that of other antihypertensive agents at recommended doses. The tolerability profile of aliskiren is placebo-like at the licensed doses of 150 and 300 mg. In particular, the discontinuation of therapy due to clinical adverse events occurs similarly among patients treated with either aliskiren or placebo. Aliskiren is not recommended in association with ACE-inhibitors or angiotensin II receptor blockers in patients with type 2 diabetes and renal impairment. Pending disclosure of full results, the early termination of the ALTITUDE seems to confirm previous concerns about the safety of the dual pharmacological blockade of the renin-angiotensin system in these patients. Aliskiren is a well-tolerated antihypertensive drug that may help to achieve the recommended targets of BP control.

Efficacy and safety of aliskiren and amlodipine combination therapy in patients with hypertension: a randomized, double-blind, multifactorial study

Most patients with hypertension need more than one drug to achieve blood pressure (BP) control. This randomized, double-blind, multifactorial study evaluated whether combinations of aliskiren and amlodipine provided superior BP reductions to component monotherapies in patients with hypertension (mean sitting diastolic BP (msDBP) 95-<110 mm Hg). Overall, 1688 patients were randomized to once-daily monotherapy with aliskiren 150 or 300 mg or amlodipine 5 or 10 mg, combination therapy with one of four corresponding aliskiren/amlodipine doses, or placebo for 8 weeks. At week 8 end point, aliskiren/amlodipine combinations provided significant msDBP reductions from baseline of 14.0-16.5 mm Hg, compared with reductions of 8.0 and 10.2 mm Hg for aliskiren 150 and 300 mg, respectively (P<0.001), and 11.0 and 13.8 mm Hg for amlodipine 5 and 10 mg, respectively (P<0.05). Aliskiren/amlodipine combinations provided reductions in mean sitting systolic BP 20.6-23.9 mm Hg, compared with decreases of 10.7 and 15.4 mm Hg for aliskiren 150 and 300 mg, respectively (P<0.001), and 15.8 and 21.0 mm Hg for amlodipine 5 (P< or =0.001) and 10 mg (P=NS), respectively. Aliskiren/amlodipine combination therapy provides greater BP lowering than either agent alone, hence offering an effective treatment option for patients with hypertension.

Treatment with aliskiren/amlodipine combination in patients with moderate-to-severe hypertension: a randomised, double-blind, active comparator trial

AIMS

To assess the extent of reduction in blood pressure (BP) of aliskiren/amlodipine combination therapy compared with amlodipine monotherapy in moderate-to-severe hypertensive patients.

METHODS

This was an 8-week multicentre, randomised, double-blind study. After a 1-to 4-week washout period, eligible patients [mean sitting systolic blood pressure (msSBP) ≥ 160 to < 200 mmHg] were randomised to receive a once-daily dose of aliskiren/amlodipine 150/5mg (n = 244) or amlodipine 5 mg (n = 241) for 1 week, followed by up-titration to aliskiren/amlodipine 300/10 mg or amlodipine 10 mg for 7 weeks. Efficacy outcome measures included change from baseline to week 8 endpoint in msSBP (primary endpoint), mean sitting diastolic blood pressure (msDBP), and BP control rate (< 140/90 mmHg). Safety was assessed by monitoring and recording all adverse events (AEs) and laboratory abnormalities.

RESULTS

Patients' demographic characteristics were balanced between the two groups, mean baseline BP being 171.0/94.3 mmHg for aliskiren/amlodipine and 171.8/95.6 mmHg for amlodipine. Of 485 randomised patients, 433 (89.3%) completed the study. At week 8 endpoint, combination therapy resulted in significantly greater msSBP/msDBP reductions and BP control rate, compared with monotherapy (all: p ≤ 0.0001). The overall incidence of AEs was similar between the two groups. The most commonly reported AE was peripheral oedema with the incidence lower for combination therapy (14.4%) than for monotherapy (18.3%).

CONCLUSION

In this population with considerably elevated BP, use of aliskiren/amlodipine combination showed significantly greater BP reductions and allowed more patients to achieve BP control compared with amlodipine monotherapy, with no additional safety concerns.

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.

Key advances in antihypertensive treatment

Although various effective treatments for hypertension are available, novel therapies to reduce elevated blood pressure, improve blood-pressure control, treat resistant hypertension, and reduce the associated cardiovascular risk factors are still required. A novel angiotensin-receptor blocker (ARB) was approved in 2011, and additional compounds are in development or being tested in clinical trials. Several of these agents have innovative mechanisms of action (an aldosterone synthase inhibitor, a natriuretic peptide agonist, a soluble epoxide hydrolase inhibitor, and an angiotensin II type 2 receptor agonist) or dual activity (a combined ARB and neutral endopeptidase inhibitor, an ARB and endothelin receptor A blocker, and an endothelin-converting enzyme and neutral endopeptidase inhibitor). In addition, several novel fixed-dose combinations of existing antihypertensive agents were approved in 2010-2011, including aliskiren double and triple combinations, and an olmesartan triple combination. Upcoming fixed-dose combinations are expected to introduce calcium-channel blockers other than amlodipine and diuretics other than hydrochlorothiazide. Finally, device-based approaches to the treatment of resistant hypertension, such as renal denervation and baroreceptor activation therapy, have shown promising results in clinical trials. However, technical improvements in the implantation procedure and devices used for baroreceptor activation therapy are required to address procedural safety concerns.

Aliskiren, amlodipine and hydrochlorothiazide triple combination for hypertension

Cardiovascular-related morbidity and mortality is linked to hypertension with proportional gains in cardiovascular risk factor reduction with the lowering of blood pressure. Clinical trial data has shown that attaining goal blood pressure requires, for most patients, at least two antihypertensive medications, with a significant proportion requiring regimens of three or more medications. Single-pill triple combinations have returned to the market following results of increased efficacy and adherence over dual- and mono-therapy. The combination of aliskiren, amlodipine and hydrochlorothiazide is a rational choice for combination therapy and recent studies suggest that it is safe and effective in lowering blood pressure in patients who fail dual combination therapy.

Comparative efficacy and safety of combination aliskiren/amlodipine and amlodipine monotherapy in African Americans with stage 2 hypertension and obesity or metabolic syndrome

The renin-angiotensin system (RAS) is a common link between hypertension and comorbidities of obesity and metabolic syndrome (MetS). We evaluated the antihypertensive efficacy and safety of the combination direct renin inhibitor, aliskiren, with amlodipine versus amlodipine alone in self-identified African Americans with stage 2 hypertension in a subgroup of patients with obesity or MetS participating in the Aliskiren Amlodipine Combination in African AmEricans with Stage 2 HypertenSion (AACESS) trial. Subjects, newly diagnosed and treatment naive or taking three or fewer antihypertensive drugs with a mean sitting systolic blood pressure (msSBP) of 160-199 mm Hg were randomized to receive aliskiren/amlodipine 150/5 mg or amlodipine 5 mg for 1 week; force-titrated to aliskiren/amlodipine 300/10 mg or amlodipine 10 mg, for an additional 7 weeks. Overall, 292 obese (body mass index ≥30 kg/m(2)) and 197 MetS subjects had baseline msSBP ranging from 167.0 to 167.5 mm Hg. Least-square mean reductions from baseline to 8 weeks in msSBP, the primary efficacy variable, were significantly higher with aliskiren/amlodipine than with amlodipine in both obese (-33.7 mm Hg vs. -27.9 mm Hg; P < .001) and MetS subjects (-36.4 mm Hg vs. -28.5 mm Hg; P < .001). Both treatments were well tolerated. Aliskiren/amlodipine 300/10 mg is more effective than amlodipine 10 mg in African Americans with stage 2 hypertension and obesity or MetS.

Direct renin inhibitor aliskiren in women with menopausal metabolic syndrome and arterial hypertension

Aim. To study the effectiveness of a direct renin inhibitor, aliskiren, in patients with menopausal metabolic syndrome (MMS), and to assess aliskiren effects on blood pressure (BP), carbohydrate and lipid metabolism parameters, microalbuminuria, and arterial stiffness. Material and methods. The study included 23 women with MMS, to whom aliskiren monotherapy (150-300 mg/d) was administered. At baseline and in the end of the study, anthropometry, carbohydrate and lipid metabolism parameters assessment, 24-hour BP monitoring, and arterial stiffness assessment by volume sphygmography were performed. Results. By the end of the study, most parameters of circadian BP profile significantly decreased. Target levels of systolic and diastolic BP were achieved in 80 % of the patients. There was a significant reduction in postprandial glucose levels. According to the volume sphygmography results, a decrease in arterial stiffness was accompanied by a significant reduction in pulse wave velocity and augmentation index, with normalization of the former parameter. Conclusion. Aliskiren therapy demonstrated not only high antihypertensive effectiveness in MMS patients, but also a reduction in postprandial glucose levels and arterial stiffness.

Comparative efficacy and safety of combination aliskiren/amlodipine and amlodipine monotherapy in African Americans with stage 2 hypertension

Initial multiple drug therapy for hypertension achieves greater and quicker reductions and higher blood pressure (BP) control rates than monotherapy. This 8-week, prospective, multicenter, randomized, double-blind study compared the efficacy and safety of the initial combination of aliskiren/amlodipine with amlodipine monotherapy in African Americans with stage 2 hypertension. After a 1- to 4-week washout, patients received aliskiren/amlodipine 150/5 mg or amlodipine 5 mg for 1 week and then were force-titrated to aliskiren/amlodipine 300/10 mg or amlodipine 10 mg for 7 weeks. At week 8, greater reductions in mean sitting systolic BP were obtained with aliskiren/amlodipine (n = 220) than with amlodipine (n = 223) (least squares mean change [standard error of the mean], -34.1 [1.14] mm Hg vs -28.9 [1.12] mm Hg; P<.001). Ambulatory and central BP measures were consistent with clinic BP findings, although these were conducted in a small subset of patients (n = 94 in ambulatory BP monitoring substudy and n = 136 for central BP). More patients achieved goal BP (<140/90 mm Hg) with aliskiren/amlodipine than with amlodipine at week 8 (57.3% vs 48.0%; P = .051). Both treatment groups had similar adverse event rates (35.0% and 32.7%, respectively). The most common adverse events were peripheral edema (7.7% with aliskiren/amlodipine and 9.0% with amlodipine), headache, fatigue, and nausea. The combination of aliskiren/amlodipine reduced peripheral, ambulatory, and central BP more than amlodipine alone with similar tolerability in African Americans with stage 2 hypertension.

Efficacy and safety of aliskiren-based dual and triple combination therapies in US minority patients with stage 2 hypertension

Minority patients with hypertension generally require combination therapy to reach blood pressure (BP) goals. We examined the BP-lowering efficacy and safety of combination aliskiren/amlodipine therapy in self-identified minority patients in the United States with stage 2 hypertension and the impact of adding hydrochlorothiazide (HCTZ) to this combination. In this 8-week double-blind study, 412 patients were randomized to receive aliskiren/amlodipine (150/5 mg) or amlodipine (5 mg) with forced titration up to aliskiren/amlodipine/HCTZ (300/10/25 mg) or aliskiren/amlodipine (300/10 mg), respectively. Overall, mean age was 55.2 years, mean body mass index was 32 kg/m(2), 62.3% were black, 28.2% were Hispanic/Latino, and 69.1% had metabolic syndrome. Mean sitting systolic blood pressure (MSSBP), the primary efficacy outcome, was reduced from 167.1 mm Hg at baseline to 130.7 mm Hg at week 8 with aliskiren/amlodipine/HCTZ and from 167.4 mm Hg to 137.9 mm Hg with aliskiren/amlodipine (P < .0001 between groups). At week 8, BP goal (<140/90 mm Hg) was achieved in 72.6% and 53.2% of patients in the two treatment groups, respectively (P < .0001). Adverse events were experienced by 34.2% and 40.2%, respectively. Combination aliskiren/amlodipine therapy was effective in treating these high-risk patients but inclusion of HCTZ provided greater antihypertensive efficacy. Both treatments were similarly well tolerated.

Efficacy of aliskiren/hydrochlorothiazide combination for the treatment of hypertension: a meta-analytical approach

BACKGROUND

Single-pill combinations of aliskiren/hydrochlorothiazide have recently been approved by the European Medicines Agency for the treatment of hypertension.

OBJECTIVE

This study aimed to assess the antihypertensive efficacy of aliskiren/hydrochlorothiazide combination in reducing systolic and diastolic blood pressure in hypertensive patients.

METHODS

A search in International Pharmaceutical Abstracts, MEDLINE, The Cochrane Library and ISI Web of Knowledge was performed from 2000 to November 2009, to identify randomized, double-blind, clinical trials using aliskiren/hydrochlorothiazide for the treatment of hypertension. Studies were included if they evaluated the antihypertensive efficacy of aliskiren/hydrochlorothiazide in patients with mild or moderate essential hypertension and age ≥ 18 years. The meta-analytical approach calculated the weighted average reductions of systolic and diastolic blood pressure for each daily dosage combination.

RESULTS

We included 5 clinical trials testing several combinations of aliskiren/hydrochlorothiazide and containing data on 5448 patients. In all studies blood pressure was assessed at inclusion (baseline) and after 8 weeks of therapy. Blood pressure reductions and control rates were significantly (p < 0.05) higher with the aliskiren/hydrochlorothiazide combinations than with placebo and the same doses of aliskiren or hydrochlorothiazide alone. The weighted mean reductions (mm Hg) from baseline of systolic and diastolic blood pressure for each aliskiren/hydrochlorothiazide combination were: -15.8/-10.3 (150/25 mg); -15.9/-11.8 (300/12.5 mg); -16.9/-11.6 (300/25 mg). Blood pressure control rates (%) for the above combinations were, at least, respectively: 43.8, 50.1 and 51.9.

CONCLUSIONS

Aliskiren/hydrochlorothiazide provided clinically significant additional blood pressure reductions and improved blood pressure control rates over aliskiren or hydrochlorothiazide monotherapy.

Safety and tolerability of the direct renin inhibitor aliskiren: a pooled analysis of clinical experience in more than 12,000 patients with hypertension

While the safety of renin-angiotensin system (RAS)-blocking drugs such as angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers is well known, less is known about the new direct renin inhibitor aliskiren. The authors pooled data from 12 randomized controlled trials of aliskiren in patients with hypertension and analyzed the incidence and types of adverse events (AEs) and laboratory abnormalities. Studies were characterized as short-term (≤2 months) placebo-controlled or long-term (>2 months) active-controlled. Relative risks for AEs of particular interest for RAS blockers were calculated. In short-term studies, AEs occurred in similar proportions of aliskiren 150 mg and 300 mg (33.6% and 31.6%, respectively) and placebo treatment groups (36.8%). In long-term studies, a lower proportion of patients treated with aliskiren 150 mg and 300 mg had AEs (33.7% and 43.2%, respectively) than those treated with ACE inhibitors (60.1%), angiotensin receptor blockers (53.9%), and thiazide diuretics (48.9%). Events of special interest, including angioedema, hyperkalemia, and diarrhea occurred in similar proportions of patients taking aliskiren, placebo, and comparator agents. In studies of up to 36 weeks, patients treated with aliskiren were significantly less likely to develop cough than those treated with ACE inhibitors. At the registered doses of 150 mg and 300 mg daily, aliskiren has safety and tolerability profiles similar to placebo, other RAS blockers, and diuretics. Cough rates are lower with aliskiren compared with ACE inhibitors.

Combined aliskiren-amlodipine treatment for hypertension in African Americans: clinical science and management issues

While it may seem at first that antihypertensive drug combinations run counter to the desire to 'personalize' the management of hypertension, the best combinations have predictable efficacy in different individuals and subpopulations. Race is probably not a valid surrogate for clinically meaningful genetic variation or guide to therapy. Most guidelines suggest similar blood pressure goals for different races but drug treatment recommendations have diverged. In the United States, race is not considered to be a major factor in drug choice, but in England and other countries, initial therapy with renin-angiotensin system blocking drugs is not recommended in Blacks. In this review we: (1) examine new trends in race-based research; (2) emphasize the weaknesses of race-based treatment recommendations; and (3) explore the effects of a new combination, renin inhibition (aliskiren) and amlodipine, in African Americans.

Effect of aliskiren addition to amlodipine on ankle edema in hypertensive patients: a three-way crossover study

OBJECTIVE

The aim of this study was to assess the effect of aliskiren and amlopidine on ankle-foot volume (AFV) and pretibial subcutaneous tissue pressure (PSTP).

RESEARCH DESIGN AND METHODS

After 4-week placebo, 120 outpatients with grade 1 - 2 hypertension were randomized to amlodipine 10 mg or aliskiren 300 mg or their combination for 8 weeks in three crossover periods. At the end of each treatment, blood pressure, AFV, PSTP, plasma renin activity (PRA) and norepinephrine were assessed.

RESULTS

Both monotherapies similarly reduced systolic blood pressure (SBP; p < 0.001) and diastolic blood pressure (DBP; p < 0.001), but the reduction was greater with amlodipine/aliskiren combination (SBP: - 24.6 mmHg, p < 0.001 vs monotherapy; DBP: -20.9 mmHg, p < 0.01 vs monotherapy). Amlodipine increased both AFV (+ 28.4%, p < 0.01) and PSTP (+ 80.4%, p < 0.01), while the combination produced a less marked increase in AFV (+ 6.6%, p < 0.01 vs amlodipine) and PSTP (+ 20.1%, p < 0.01 vs amlodipine). Plasma norepinephrine increased with amlodipine (+ 53.5%, p < 0.01) and this increase was not reduced by aliskiren addition. PRA was unaffected by amlodipine, while it was reduced by both aliskiren monotherapy (- 77.7%, p < 0.01) and aliskiren/amlodipine combination (- 75.7%, p < 0.01).

CONCLUSIONS

Direct renin inhibition by aliskiren partially counteracts the microcirculatory changes responsible for calcium-channel-induced edema formation, possibly through preferential vasodilation of venous capacitance vessels.

Direct renin inhibition: update on clinical investigations with aliskiren

The renin–angiotensin–aldosterone system (RAAS) plays a pivotal role in regulating blood pressure, volume, and electrolytes. The final product of RAAS cascade is angiotensin II, which exerts diverse biological activities via binding to one of three known receptor types, with different binding consequences. Despite the success with conventional strategies to limit angiotensin II production and action, these agents promote a reflex rise in plasma renin activity, which is thought to be associated with an increased incidence of cardiovascular events. Several renin inhibitors have been synthesized in order to counteract deleterious consequences of renin activity and RAAS activation; aliskiren is the first of these new non-peptide direct renin inhibitors to be approved for the treatment of hypertension. The paper reviews pharmacokinetics of aliskiren and its role in hypertension, with particular regard to those studies that compared clinical efficacy of aliskiren in comparison and in addition to other antihypertensive drug strategies.

Role of aliskiren in blood pressure control and renoprotection

Patients with chronic renal disease are at increased risk for the development of cardiovascular disease, which is the main cause of death in this growing population. Among the risk factors involved, hypertension and proteinuria are major contributors to kidney damage and, if not controlled, may eventually lead to the progression of renal failure and end-stage renal disease. Both proteinuria and hypertension can be primary pathologic events or can appear as complications of other disease processes. Initially, these two factors may operate separately but, as progression ensues, both processes generally combine, potentiating their effects and hastening renal damage. Therefore, strategies to reduce blood pressure and proteinuria are essential in order to slow the worsening of many nephropathies. Therapies that target the renin-angiotensin system offer particular benefit, as hypertension and proteinuria can be precisely reduced with angiotensin-converting enzyme inhibitors and/or angiotensin receptor blockers. However, with this intervention, plasma renin activity remains high, and although primary endpoints may be controlled, elevated renin concentration can contribute to cardiovascular damage. Aliskiren, a direct renin inhibitor, is the first example of a novel class of antihypertensive drugs with potent antiproteinuric effects, which, alone or combined, can contribute to delaying the progression of kidney disease.

Aliskiren in the management of hypertension

Angiotensin-converting enzyme inhibitors and angiotensin II type 1 receptor antagonists (angiotensin receptor blockers) have been shown to be effective drugs in the management of hypertension and to have beneficial effects along the cardiovascular continuum. However, due to compensatory mechanisms, both of these types of agent increase plasma renin activity, which has been reported to have deleterious effects on patient outcomes. Aliskiren is the first nonpeptide orally administered direct renin inhibitor available on the market. Reported data have shown that aliskiren effectively reduces BP alone or in combination with other antihypertensive agents, and has a good tolerability profile. Moreover, this agent reduces plasma renin activity, which in theory could have additional clinical benefits. However, clinical trials analyzing the effects of aliskiren on mortality are still ongoing.

New class of agents for treatment of hypertension: focus on direct renin inhibition

Aliskiren, the first orally active direct renin inhibitor, is an effective antihypertensive drug with distinctive characteristics, including good blockade of the renin-angiotensin system, a prolonged duration of action, pharmacologic effects that persist after drug discontinuation, and favorable tolerability comparable with placebo. The blood pressure-lowering effect of aliskiren monotherapy is similar, if not superior, to that of other first-line antihypertensive agents, and is greatly enhanced when aliskiren is combined with various other antihypertensive medications, without any adverse drug interactions. Aliskiren is also an effective and well tolerated therapy in special populations, including diabetic, obese, and elderly hypertensives. Beyond its blood pressure-lowering efficacy, results from experimental and clinical trials suggest that aliskiren has positive effects on markers of cardiovascular and renal damage. The ASPIRE (Aliskiren Study in Post-MI patients to Reduce rEmodelling) HIGHER clinical trials program is further assessing whether the promising pharmacologic properties of aliskiren translate into reduced risk of adverse cardiovascular and renal outcomes.

Current concepts in combination therapy for the treatment of hypertension: combined calcium channel blockers and RAAS inhibitors

Recent guidelines for the management of hypertension recommend target blood pressures <140/90 mmHg in hypertensive patients, or <130/80 mmHg in subjects with diabetes, chronic kidney disease, or coronary artery disease. Despite the availability and efficacy of antihypertensive drugs, most hypertensive patients do not reach the recommended treatment targets with monotherapy, making combination therapy necessary to achieve the therapeutic goal. Combination therapy with 2 or more agents is the most effective method for achieving strict blood pressure goals. Fixed-dose combination simplifies treatment, reduces costs, and improves adherence. There are many drug choices for combination therapy, but few data are available about the efficacy and safety of some specific combinations. Combination therapy of calcium antagonists and inhibitors of the renin-angiotensin-aldosterone system (RAAS) are efficacious and safe, and have been considered rational by both the JNC 7 and the 2007 European Society of Hypertension – European Society of Cardiology guidelines for the management of arterial hypertension. The aim of this review is to discuss some relevant issues about the use of combinations with calcium channel blockers and RAAS inhibitors in the treatment of hypertension.

Direct inhibition of renin: a physiological approach to treat hypertension and cardiovascular disease

Despite the last three decades of progress in improving cardiovascular outcomes via renin–angiotensin–aldosterone system (RAAS) blockade in hypertensive patients, substantial residual morbidity/mortality remains. Attempts to improve clinical outcomes by combining angiotensin-converting enzyme inhibitors and angiotensin receptor blockers have yielded mixed results. Adverse effects of RAAS blockade with angiotensin-converting enzyme inhibitors and angiotensin receptor blockers may relate to compensatory increases in plasma renin activity (PRA). The first-in-class direct renin inhibitor, aliskiren, blocks the RAAS at its point-of-activation, suppressing PRA and attenuating increases associated with other antihypertensives. Aliskiren (with or without other agents) provides significant and prolonged blood pressure reductions in a broad range of hypertensive patients and is well tolerated. Initial results from organ-protection studies are promising. Long-term outcomes studies should yield valuable information regarding the significance of direct renin inhibition in clinical practice.