Combining renin-angiotensin-aldosterone system blockade with diuretic therapy for treatment of hypertension

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.

Combination use of angiotensin converting enzyme inhibitors and angiotensin receptor blockers in diabetic kidney disease

Angiotensin converting enzyme inhibitors (ACE-I) and angiotensin receptor blockers (ARB) have played a major role in slowing the progression of diabetic kidney disease, since they lower urine protein levels, lower blood pressure, and slow progression. Studies have suggested that the combination of ACE-I and ARB offered greater benefits for patients with diabetic kidney disease. In 2008, the large ONTARGET study reported no benefit with combination therapy, as compared with monotherapy. This study has changed practice patterns, but few patients in this study had diabetic kidney disease. In this review, the data in favor of the combination use of these agents in patients with diabetic kidney disease and data against the combination are reviewed. At this time, there is little support for using the combination in diabetic patients with no kidney disease or early stage diabetic kidney disease. But there are patients who may benefit from combination use.

50 years of thiazides: should thiazide diuretics be considered third-line hypertension treatment?

The purpose of this report is to review available and emerging antihypertensive treatment options in light of current guidelines and evidence from large clinical trials. The published literature was reviewed for evidence regarding first-line options for antihypertensive agents, including thiazide-type diuretics, as monotherapy or as part of combination therapy. Current guidelines recommend using thiazide-type diuretics as first-line therapy alone or in combination with another agent. Other commonly used antihypertensive agents include calcium channel blockers, β-adrenergic receptor blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and the direct renin inhibitor, aliskiren. These agents are associated with varying degrees of evidence that they may provide protection from cardiovascular or renal disease beyond that associated with blood pressure reduction. Thiazide diuretics are inexpensive and effective but may not be preferable to other classes of antihypertensives that reduce blood pressure to a similar extent with a better safety profile and superior reductions in cardiovascular event rates. However, calcium channel blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and direct renin inhibitors also show promise as initial monotherapy or as part of a combination therapy regimen. In patients requiring additional blood pressure reduction, add-on therapy with a diuretic could provide additional blood pressure-lowering efficacy.

Efficacy and safety of delapril/indapamide compared to different ACE-inhibitor/hydrochlorothiazide combinations: a meta-analysis

The main objective of this meta-analysis was to compare the efficacy of the combination of delapril and indapamide (D+I) to different angiotensin-converting enzyme inhibitor (ACEi) plus hydrochlorothiazide (HCTZ) combinations for the treatment of mild-to-moderate hypertension. A secondary objective was to examine the safety of these two combinations. Studies comparing the efficacy of D+I to ACEi+HCTZ combinations in hypertensive patients and published on computerized databases (1974–2010) were considered. Endpoints included percentage of normalized patients, of responders, change in diastolic and systolic blood pressure (DBP/SBP) at different time-points, percentage of adverse events (AEs), and percentage of withdrawal. Four head-to-head randomized controlled trials (D+I-treated, n = 643; ACEi+HCTZ-treated, n = 629) were included. Meta-analysis indicated that D+I-treated patients had a higher proportion with normalized blood pressure (P = 0.024) or responders (P = 0.002) compared to ACEi+HCTZ-treated patients. No difference was observed between treatments on absolute values of DBP and SBP at different time-points. Although the rate of patients reporting at least one AE was similar in both groups (10.4% versus 9.9%), events leading to study withdrawal were lower in the D+I group versus the ACEi+HCTZ group (2.3% versus 4.8%, respectively; P = 0.018). This meta-analysis suggests that treatment with D+I could provide a higher proportion of normalized or responder patients with good tolerability compared to ACEi+HCTZ combinations.

Candesartan in the treatment of hypertension: what have we learnt in the last decade?

INTRODUCTION

Although all of the first-line antihypertensive drugs effectively reduce blood pressure, there are some conditions that may favor the use of angiotensin receptor blockers over others, such as left ventricular hypertrophy, microalbuminuria, renal dysfunction, diabetes, or metabolic syndrome, among others.

AREAS COVERED

This manuscript reviewed the data supporting the use of candesartan cilexetil in hypertensive population with a special focus on its efficacy and safety. For this purpose, a search on MEDLINE and EMBASE databases was performed. The MEDLINE and EMBASE search included both medical subject headings (MeSH) and keywords including: candesartan OR angiotensin receptor blockers OR renin angiotensin system AND hypertension treatment. References of the retrieved articles were also screened for additional studies. There were no language restrictions.

EXPERT OPINION

Candesartan, a long-acting angiotensin receptor antagonist, has been shown to be an effective and well-tolerated therapy in the entire spectrum of hypertensive patients, including those at higher risk, such as those with diabetes, metabolic syndrome, left ventricular hypertrophy, or microalbuminuria.

Efficacy, safety, and tolerability of valsartan/hydrochlorothiazide in Asian patients with essential hypertension

INTRODUCTION

Previous studies have demonstrated that hypertensive patients need concomitant therapy with one or more drugs from different classes of antihypertensive agents to achieve their blood pressure control targets. We performed the first multinational observational study of valsartan/hydrochlorothiazide (HCTZ) single pill combination in Asia to determine the efficacy, safety, and tolerability in hypertensive patients. The objective of this multinational, multicenter, 24-week follow-up observational study is to evaluate the efficacy, safety, and tolerability of valsartan/hydrochlorothiazide single pill combination in the treatment of essential hypertension in the Asia-Pacific region.

METHODS

A total of 7567 Asian patients who were diagnosed with stage 1 or stage 2 essential hypertension and who took at least one dose of valsartan/hydrochlorothiazide single pill combination were included in the statistical analyses. A total of 59% were taking antihypertensive medication at the time of the study. Eligible patients received valsartan/hydrochlorothiazide single pill combination 80/12.5 mg tablets orally once daily at visit 1. The investigator could decide the subsequent dose of valsartan/hydrochlorothiazide single pill combination for their patients, and efficacy, safety, and tolerability data were collected at week 4, 12, and 24.

RESULTS

Basal blood pressure was 155.9±13.3 mmHg (systolic) and 96.3±10.1 mmHg (diastolic). Response rates and control rates increased continuously from baseline to the study endpoint at week 24, when they reached 94.6% and 73.2%, respectively. Systolic and diastolic blood pressure reductions were -25.4±15.2 mmHg and -14.9±13.5 mmHg, respectively (P<0.001). Using a four-point global assessment scale, 96.8% of the patients and physicians reported good, very good, or excellent for both their subjective efficacy and tolerability assessments.

CONCLUSION

In this multicenter, multicountry study including 7567 Asian patients with hypertension, valsartan/hydrochlorothiazide single pill combination was found efficacious, well tolerated, and devoid of any serious adverse effects.

Valsartan-amlodipine-hydrochlorothiazide: the definitive fixed combination?

A significant proportion of patients with hypertension will need three or more antihypertensive agents to achieve blood pressure goals, particularly those at higher risk. On the other hand, fixed combinations provide an extra beneficial effect, as they improve medication adherence and, secondarily, the attainment of blood pressure goals during follow-up. Triple therapy is recommended in the treatment of hypertension in those patients not adequately controlled with two antihypertensive drugs. In this context, guidelines recommend the combination of a renin-angiotensin system inhibitor, a calcium channel blocker and a diuretic. The triple fixed combination of valsartan-amlodipine-hydrochlorothiazide has been shown to be an effective and safe therapy for treating hypertension and seems a logical approach for those patients uncontrolled with two antihypertensive agents as well as in those patients already treated with three drugs to improve treatment compliance. In this article, available evidence about the efficacy and tolerability of the triple fixed combined therapy valsartan-amlodipine-hydrochlorothiazide for the treatment of hypertension is updated.

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.

A critical appraisal of the clinical effectiveness of a fixed combination of valsartan, amlodipine, and hydrochlorothiazide in achieving blood pressure goals

Recent guidelines for the treatment of hypertension have focused on the need for multiple medications to get most patients to goal blood pressure (BP). Two to three different classes of antihypertensive agents are frequently required, increasing the risk of poor compliance with therapy. Hence, the guidelines have recommended starting with combination therapy in patients with BP that is over 20 mm Hg systolic or 10 mm Hg diastolic above goal. The latest advance in treatment regimen has been the development of triple-therapy combinations of an angiotensin receptor blocker, amlodipine, and hydrochlorothiazide. We review the pathophysiologic rationale for such a combination and the efficacy, safety, and tolerability of the first triple therapy that has become available: valsartan + amlodipine + hydrochlorothiazide. Finally, we suggest that use of triple therapy could improve the accuracy of diagnosing resistant hypertension, an increasingly prevalent and severe condition, by enhancing adherence to treatment and weeding out patients with pseudoresistance. This would allow for implementation of expensive and invasive workup only in those truly resistant patients in whom it is justified.

The diabetic CKD patient--a major cardiovascular challenge

The diabetic patient with chronic kidney disease (CKD) is at very high risk of cardiovascular disease (CVD). Primary and secondary CVD prevention is of major importance and should be targeted at both traditional cardiovascular risk factors and risk factors specific for patients with CKD, such as albuminuria, anaemia and CKD--mineral and bone disorder. However, treatment goals have largely been derived from clinical trials including patients with no or only mild CKD and may not be generalizable to patients with advanced renal disease. Moreover, in patients on renal replacement therapy, the association between traditional CVD risk factors and the incidence of CVD may be reversed, and pharmaceutical interventions that are beneficial in the general population may be ineffective or even harmful in this high-risk population. Those involved in the delivery of care to patients with diabetes and CKD need to be aware of these issues and should adopt an individualised approach to treatment.

Complementary mechanisms of action and rationale for the fixed combination of perindopril and indapamide in treating hypertension - update on clinical utility

Although reducing blood pressure is the most important approach to reduce cardiovascular outcomes in the hypertensive population, the majority of patients fail to attain the targets. Most patients with hypertension need at least 2 antihypertensive agents to achieve blood pressure goals. The 2007 European hypertension guidelines state that combined therapy is needed when monotherapy does not attain blood pressure objectives and as a first-line treatment in high-risk patients. This point has been reinforced in the 2009 update of the European guidelines. The advantages of combination therapy are well documented with the potential for increased antihypertensive efficacy as a result of different mechanisms of action, and a lower incidence of adverse effects because of the lower doses used and the possible compensatory responses. Moreover, the use of fixed dose combinations are specially recommended as they facilitate treatment compliance. The inhibition of the renin-angiotensin system appears to be very beneficial in the treatment of patients with hypertension along the cardiovascular continuum and the combination of a renin-angiotensin system inhibitor and a diuretic is particularly recommended. Many clinical trials have demonstrated the benefits of the fixed combination perindopril/indapamide in the treatment of hypertension. The aim of this manuscript is to update the published data on the efficacy and safety of this fixed combination.

Comparison of the effects of doxazosin and atenolol on target organ damage in adults with type 2 diabetes mellitus and hypertension in the CARDHIAC study: a 9-month, prospective, randomized, open-label, blinded-evaluation trial

OBJECTIVE

The CARDHIAC (CARduran en pacientes Diabéticos con HIpertensi'on Arterial no Controlada) trial examined the effects of doxazosin gastrointestinal therapeutic system (GITS) and atenolol on 3 separate measures of target-organ damage--left ventricular mass index (LVMI), carotid intima media thickness (IMT), and urinary albumin excretion (UAE)--in patients with type 2 diabetes mellitus and hypertension.

METHOD

This trial had a prospective, open-label, blinded-evaluation design and a duration of 9 months. Patients whose blood pressure (BP) was uncontrolled (systolic BP > or = 130 mm Hg and/or diastolic BP > or = 80 mm Hg) despite at least 1 month of treatment with a renin-angiotensin blocker and diuretic were randomly allocated to receive doxazosin GITS 4 mg or atenolol 50 mg once daily in addition to their existing treatment. Seated BP was measured at study visits at 1, 3, 6 and 9 months; if the BP goal was not achieved at any visit, the dose of doxazosin or atenolol was titrated upward to 8 or 100 mg, respectively. Treatment compliance (pill count) and adverse reactions were monitored at each visit. Each patient underwent echocardiography and Doppler ultrasonography at baseline and at the end of the study for evaluation of the change in LVMI. The change in carotid IMT was evaluated by carotid ultrasound examination at the same time points. UAE also was measured at baseline and the end of the study.

RESULTS

Sixty patients (100% white; 51% female; mean [SD] age, 63.4 [7.5] years; body mass index, 28.2 [3.4] kg/m(2)) were randomized to receive doxazosin GITS (n=32) or atenolol (n=28). At baseline, mean BP was 150.2 (10.6)/90.1 (7.3) mm Hg in the doxazosin group and 153.1 (13.8)/92.3 (6.1) mm Hg in the atenolol group (P=NS). At the end of the study, BP had decreased by 10.1 (3.2)/5.2 (1.3) mm Hg in the doxazosin group and 12.2 (4.2)/6.3 (2.1) mm Hg in the atenolol group (both, P<0.001 vs baseline; P=NS between groups). Heart rate at the end of the study was 78(6) beats/min in the doxazosin group (P=NS vs baseline) and 66(7) beats/min in the atenolol group (P<0.01 vs baseline and between groups). LVMI decreased by 10.8 in the doxazosin group (P=0.001 vs baseline) and 4.2% in the atenolol group (P=NS vs baseline; P=0.03 between groups). The changes in carotid IMT and UAE were not statistically significant between groups.

CONCLUSIONS

In this study in hypertensive patients with type 2 diabetes, LVMI was significantly decreased in doxazosin-treated patients relative to baseline and compared with atenolol-treated patients. The differences in carotid IMT and UAE were not statistically significant between groups.

A role for single-pill triple therapy in hypertension

Hypertension remains the most prevalent chronic disease in the world, and its adequate treatment results in predictable reductions in cardiovascular morbidity and mortality. However, most hypertensive subjects do not achieve goal blood pressure despite availability of multiple antihypertensive agents with various pharmacological mechanisms of action and relatively few side effects. We review the reasons for low hypertension control rates, including factors that affect patients' adherence to therapy, number of agents required to achieve goal blood pressure, pathophysiology-based selection of therapy and diagnosis of resistant hypertension. Within this framework, we discuss the possible impact of a single-pill, triple-therapy combination with an antagonist of the renin—angiotensin system, a calcium-channel blocker and a diuretic. We focus on possible differential diagnostic implications in terms of refractoriness to treatment, and therapeutic implications in terms of successful blood pressure control. We conclude that a single-pill, triple-therapy combination may improve control of hypertension by enhancing compliance, by achieving blood pressure goal rapidly and by reducing physician inertia in prescribing adequate antihypertensive therapy. We also suggest that such a combination may lead to improved accuracy in diagnosing resistant hypertension in general practice, avoiding unnecessary further workup and referrals to hypertension specialists.

Fixed combinations in the management of hypertension: perspectives on lercanidipine-enalapril

Although achieving blood pressure (BP) control is critical to improve cardiovascular prognosis in hypertensive patients, many of them fail to achieve BP goals. The majority of hypertensive patients need more than one antihypertensive agent to attain BP targets. Combination therapy is required when monotherapy fails to attain BP objectives and as a first-line treatment in certain situations, such as markedly elevated BP values, when lower targets are required in high or very high cardiovascular risk patients. The advantages of combination therapy are well documented, with an increased antihypertensive efficacy as a result of the simultaneous inhibition of different mechanisms of action and with a lesser incidence of adverse events, because of the possible compensatory responses and the lower doses used. Calcium channel blockers are effective drugs in the treatment of hypertension. The efficacy of lercanidipine has been evaluated in several noncomparative and in comparative studies showing a great efficacy with a good tolerability. On the other hand, the inhibition of the renin-angiotensin system appears to be very beneficial in the treatment of patients with hypertension. Enalapril is an effective and well tolerated angiotensin converting enzyme inhibitor. Although there are several fixed-combination drugs, the combination lercanidipine plus enalapril appears to be one of the most promising therapies in the treatment of hypertension. The aim of this manuscript is to update the published data about the efficacy and safety of this fixed combination.

A review of telmisartan in the treatment of hypertension: blood pressure control in the early morning hours

Measurement of blood pressure in the clinic may provide a false impression of blood pressure control. Ambulatory blood pressure monitoring (ABPM) allows the automatic recording of the circadian variation in blood pressure and evaluation of the efficacy of antihypertensive medication throughout the dosing interval. Ambulatory blood pressure provides more effective prediction of cardiovascular risk; blood pressure control at the time of heightened risk in the early morning after waking and before taking the next dose of medication is becoming important in order to improve long-term prognosis. To achieve blood pressure control in the early morning, a long-acting antihypertensive agent is essential. Telmisartan, an angiotensin II receptor blocker, as well as having a terminal elimination half-life of 24 h, has a large volume of distribution due to its high lipophilicity. The efficacy of telmisartan 80 mg monotherapy has been demonstrated using ABPM, with superior reduction in mean values for the last 6 h of the dosing interval compared with ramipril 10 mg and valsartan 80 mg. In addition, telmisartan 80 mg provides superior blood pressure control after a missed dose compared with valsartan 160mg. When combined with hydrochlorothiazide (HCTZ) 12.5 mg, telmisartan 40mg and 80mg is more effective than losartan/HCTZ (50/12.5 mg) at the end of the dosing interval. Furthermore, greater reductions in last 6 h mean systolic blood pressure (SBP) and diastolic blood pressure (DBP) are achieved with telmisartan/HCTZ (80/12.5 mg) than with valsartan/HCTZ (160/12.5 mg) in obese patients with type 2 diabetes and hypertension. Recent data from a large group of patients show that telmisartan 80 mg controls the early morning blood pressure surge more effectively than ramipril 5-10 mg and, thus, may have a greater beneficial effect on long-term cardiovascular risk. This supposition is being tested in the ONgoing Telmisartan Alone and in combination with Ramipril Global Endpoint Trial (ONTARGET) programme.

Renin inhibition with aliskiren provides additive antihypertensive efficacy when used in combination with hydrochlorothiazide

OBJECTIVES

Aliskiren is a novel, orally active renin inhibitor. Its antihypertensive efficacy and safety, alone and in combination with hydrochlorothiazide (HCTZ), were investigated in an 8-week, double-blind, placebo-controlled trial in hypertensive patients. The effects of these treatments on plasma renin activity (PRA) were also assessed.

METHODS

A total of 2776 patients aged >or=18 years with mean sitting diastolic blood pressure (MSDBP) 95-109 mmHg were randomized to receive once-daily treatment with aliskiren (75, 150 or 300 mg), HCTZ (6.25, 12.5 or 25 mg), the combination of aliskiren and HCTZ, or placebo, in a factorial design. The primary endpoint was the change in MSDBP from baseline to week 8. PRA was assessed at these timepoints at selected study centers.

RESULTS

Aliskiren monotherapy was superior to placebo (P < 0.001; overall Dunnett's test) in reducing MSDBP and mean sitting systolic blood pressure (MSSBP). Combination treatment was superior to both component monotherapies in reducing BP (maximum MSSBP/MSDBP reduction of 21.2/14.3 mmHg from baseline with aliskiren/HCTZ 300/25 mg), and resulted in more responders (patients with MSDBP < 90 mmHg and/or >or=10 mmHg reduction) and better control rates (patients achieving MSSBP/MSDBP < 140/90 mmHg) than either monotherapy. Aliskiren monotherapy reduced PRA by up to 65% from baseline. Although HCTZ monotherapy increased PRA by up to 72%, PRA decreased in all of the combination therapy groups. All active treatments were well tolerated.

CONCLUSIONS

Aliskiren monotherapy demonstrated significant BP lowering, and its effect was considerably greater when combined with HCTZ. Renin inhibition with aliskiren neutralized the compensatory rise in PRA induced by HCTZ.