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

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.

First-line combination therapy versus first-line monotherapy for primary hypertension

BACKGROUND

This is the first update of a review originally published in 2017. Starting with one drug and starting with a combination of two drugs are strategies suggested in clinical guidelines as initial treatment of hypertension. The recommendations are not based on evidence about clinically relevant outcomes. Some antihypertensive combinations have been shown to be harmful. The actual harm-to-benefit balance of each strategy is unknown.

OBJECTIVES

To determine if there are differences in clinical outcomes between monotherapy and combination therapy as initial treatment for primary hypertension.

SEARCH METHODS

The Cochrane Hypertension Information Specialist searched the following databases for randomised controlled trials up to April 2019: the Cochrane Hypertension Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (from 2005), Embase (from 1974), the World Health Organization International Clinical Trials Registry Platform, and ClinicalTrials.gov. We used no language restrictions. We also searched clinical studies repositories of pharmaceutical companies, reviews of combination drugs on the US Food and Drug Administration and European Medicines Agency websites, and lists of references in reviews and clinical practice guidelines.

SELECTION CRITERIA

We included randomised, double-blind trials with at least 12 months' follow-up in adults with primary hypertension (systolic blood pressure/diastolic blood pressure 140/90 mmHg or higher, or 130/80 mmHg or higher if participants had diabetes), which compared combination of two first-line antihypertensive drugs with monotherapy as initial treatment. Trials had to include at least 50 participants per group and report mortality, cardiovascular mortality, cardiovascular events, or serious adverse events.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion, evaluated the risk of bias, and performed data entry. The primary outcomes were mortality, serious adverse events, cardiovascular events, and cardiovascular mortality. Secondary outcomes were withdrawals due to drug-related adverse effects, reaching blood pressure control (as defined in each trial), and blood pressure change from baseline. Analyses were based on the intention-to-treat principle. We summarised data on dichotomous outcomes as risk ratios (RR) with 95% confidence intervals (CI).

MAIN RESULTS

This update included one new study in which a subgroup of participants met our inclusion criteria. As none of the four included studies focused solely on people initiating antihypertensive treatment, we asked investigators for data for this subgroup. One study (PREVER-treatment 2016) used a combination of thiazide-type diuretic/potassium-sparing diuretic; as the former is not indicated in monotherapy, we analysed this study separately. The three original trials in the main comparison (monotherapy: 335 participants; combination therapy: 233 participants) included outpatients, mostly European and white people. Two trials only included people with type 2 diabetes; the remaining trial excluded people treated with diabetes, hypocholesterolaemia, or cardiovascular drugs. The follow-up was 12 months in two trials and 36 months in one trial. It is very uncertain whether combination therapy versus monotherapy reduces total mortality (RR 1.35, 95% CI 0.08 to 21.72), cardiovascular mortality (zero events reported), cardiovascular events (RR 0.98, 95% CI 0.22 to 4.41), serious adverse events (RR 0.77, 95% CI 0.31 to 1.92), or withdrawals due to adverse effects (RR 0.85, 95% CI 0.53 to 1.35); all outcomes had 568 participants, and the evidence was rated as of very low certainty due to serious imprecision and for using a subgroup that was not defined in advance. The confidence intervals were extremely wide for all important outcomes and included both appreciable harm and benefit. The PREVER-treatment 2016 trial, which used a combination therapy with potassium-sparing diuretic (monotherapy: 84 participants; combination therapy: 116 participants), included outpatients. This trial was conducted in Brazil and had a follow-up of 18 months. The number of events was very low and confidence intervals very wide, with zero events reported for cardiovascular mortality and withdrawals due to adverse events. It is very uncertain if there are differences in clinical outcomes between monotherapy and combination therapy in this trial.

AUTHORS' CONCLUSIONS

The numbers of included participants, and hence the number of events, were too small to draw any conclusion about the relative efficacy of monotherapy versus combination therapy as initial treatment for primary hypertension. There is a need for large clinical trials that address the review question and report clinically relevant endpoints.

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.

First-line combination therapy versus first-line monotherapy for primary hypertension

BACKGROUND

Starting with one drug and starting with a combination of two drugs are strategies suggested in clinical guidelines as initial treatment of hypertension. The recommendations are not based on evidence about clinically relevant outcomes. Some antihypertensive combinations have been shown to be harmful. The actual harm-to-benefit balance of each strategy is unknown.

OBJECTIVES

To determine if there are differences in clinical outcomes between monotherapy and combination therapy as initial treatment for primary hypertension.

SEARCH METHODS

We searched the Hypertension Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL, 2016, Issue 2), Ovid MEDLINE, Ovid Embase, LILACS, ClinicalTrials.gov, Current Controlled Trials, and the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) up to February 2016. We searched in clinical studies repositories of pharmaceutical companies, reviews of combination drugs in Food and Drug Administration and European Medicines Agency, and lists of references in reviews and clinical practice guidelines.

SELECTION CRITERIA

Randomized, double-blind trials with at least 12 months' follow-up in adults with primary hypertension (systolic blood pressure/diastolic blood pressure 140/90 mmHg or higher, or 130/80 mmHg or higher if participants had diabetes), which compared combination of two first-line antihypertensive drug with monotherapy as initial treatment. Trials had to include at least 50 participants per group and report mortality, cardiovascular mortality, cardiovascular events or serious adverse events.

DATA COLLECTION AND ANALYSIS

Two authors independently selected trials for inclusion, evaluated the risk of bias and entered the data. Primary outcomes were mortality, serious adverse events, cardiovascular events and cardiovascular mortality. Secondary outcomes were withdrawals due to drug-related adverse effects, reaching blood pressure control (as defined in each trial) and blood pressure change from baseline. Analyses were based on the intention-to-treat principle. We summarized data on dichotomous outcomes as risk ratios with 95% confidence intervals.

MAIN RESULTS

We found three studies in which a subgroup of participants met our inclusion criteria. None of the studies focused solely on people initiating antihypertensive treatment so we asked investigators for data for this subgroup (monotherapy: 335 participants; combination therapy: 233 participants). They included outpatients, and mostly European and white people. Two trials included only people with type 2 diabetes, whereas the other trial excluded people treated with diabetes, hypocholesterolaemia or cardiovascular drugs. The follow-up was 12 months in two trials and 36 months in one trial. Certainty of evidence was very low due to the serious imprecision, and for using a subgroup not defined in advance. Confidence intervals were extremely wide for all important outcomes and included both appreciable harm and benefit.

AUTHORS' CONCLUSIONS

The numbers of included participants and, hence the number of events, were too small to draw any conclusion about the relative efficacy of monotherapy versus combination therapy as initial treatment for primary hypertension. There is a need for large clinical trials that address the question and report clinically relevant endpoints.

Lercanidipine/enalapril combination in the management of obesity-related hypertension

Obesity-related hypertension represents a condition frequently observed in current clinical practice characterized by a complex pathophysiological background and a very high cardiovascular risk profile, particularly in severely obese individuals. This explains, on the one hand, the difficulty in reducing elevated blood pressure values in this pathological state and, on the other, the need to achieve this goal in a relatively short-time period to prevent the occurrence of fatal and nonfatal cardiovascular events. Both nonpharmacological and pharmacological measures are available in the therapeutic approach for this condition. Among the pharmacological interventions, a combination of two antihypertensive drugs represents the most common recommended strategy aimed at achieving blood pressure control. This paper, after briefly examining the main pathophysiological features of obesity-related hypertension, will review the importance in the treatment of this condition of the drug combination based on a calcium channel blocker and an angiotensin-converting enzyme inhibitor, with specific focus on lercanidipine/enalapril. Following an analysis of the main pharmacological properties of the combination, the results of the studies based on this pharmacological approach in obesity-related hypertension will be critically discussed. The efficacy, safety, and tolerability profile of the lercanidine/enalapril drug combination as well as its potential limitations will also be examined.

Comparative evaluation of aliskiren, ramipril, and losartan on psychomotor performance in healthy volunteers: A preliminary report

AIM

To compare the effects of aliskiren, ramipril, and losartan on the psychomotor performance in healthy volunteers.

MATERIALS AND METHODS

In this preliminary, single-dose, open-label, cross-over study conducted in 12 healthy volunteers, psychomotor assessment was carried out by four tests: Simple reaction time (SRT), multiple choice reaction time test (MCRT), critical flicker fusion frequency threshold test (CFFT), and tracking performance test (TPT). Each volunteer received a single dose of each of the three test drugs with a washout period of 10 days between different test sessions and then evaluated for post-drug scores at 2-h intervals up to 12 h and then at 24 h. The changes from the baseline scores by the test drug were statistically analyzed.

RESULTS

All the three antihypertensive drugs caused significant improvement in a similar fashion on SRT, MCRT calculated as error index, CFFT, and TPT. Aliskiren caused numerically more improvement than the other two test drugs, suggesting better cognitive profile. However, inter-drug comparisons were nonsignificant.

CONCLUSION

The results of the study highlight improvement of the cognitive functions equally by ramipril, losartan, and aliskiren. The results of the study could be of immense clinical utility in ambulatory hypertensive patients especially engaged in sensory-motor coordination tasks like driving and operating on mechanical tools.

Effects of aliskiren on blood pressure and humoral factors in hypertensive hemodialysis patients previously on angiotensin II receptor antagonists

BACKGROUND

A direct renin inhibitor (DRI), aliskiren, may be effective for blood pressure (BP) control in hemodialysis patients. However, it is unclear whether aliskiren has a greater beneficial effect on BP and humoral factors than angiotensin II receptor antagonists (ARBs) in hypertensive patients on hemodialysis.

METHODS

Eighteen hemodialysis patients (58 ± 14 years) on the recommended dose of an ARB were prospectively randomized into two groups: ARB and DRI groups. Patients in the ARB group continued taking their previous ARB, whereas those in the DRI group switched to aliskiren (150 mg/day) for 12 weeks. Baseline measurements of BP and humoral factors such as plasma renin activity (PRA), plasma aldosterone concentration (PAC) and brain natriuretic peptide (BNP) were performed. Measurements were repeated every 4 weeks.

RESULTS

At baseline, no differences were observed in age, gender or BP between the two groups. Systolic BP was unaffected by treatment in either groups (group effect, p = 0.26; time effect, p = 0.38; group × time effect, p = 0.24). PRA decreased in DRI (p ≤ 0.02, group effect, p = 0.65; time effect, p = 0.13; group × time effect, p = 0.048), but not in ARB (p ≥ 0.94). PAC increased only in DRI (p ≤ 0.03), whereas BNP was unaffected in either group.

CONCLUSION

Aliskiren at a dose of 150 mg/day had a similar effect on BP compared with ARBs, but significantly lowered PRA.

(-)Doxazosin is a necessary component for the hypotensive effect of (±)doxazosin during long-term administration in conscious rats

AIM

Doxazosin is a racemic mixture of (-)doxazosin and (+)doxazosin that is currently used as an add-on therapy for hypertension. In this study we investigated the contribution of each enantiomer to the hypotensive action of long-term administration of (±)doxazosin in conscious rats.

METHODS

Blood pressure of conscious SD rats was measured using a volume pressure recording system. The rats were orally administered (-)doxazosin, (+)doxazosin, or (±)doxazosin (8 mg·kg(-1)·d(-1)) for 12 weeks. Plasma concentrations of the agents were analyzed with HPLC. The effect of the agents on α1-adrenoceptor was examined in isolated rat caudal artery preparations.

RESULTS

Treatment of conscious rats with a single dose of (±)doxazosin (8 mg/kg) did not affected DBP and MBP, but significantly decreased SBP by 11.9% 4 h after the administration. Long-term treatment of conscious rats with (±)doxazosin significantly decreased SBP, DBP and MBP with a maximal decrease of SBP by 29.3% 8 h after the last administration. The rank order of the hypotensive actions caused by long-term treatment in conscious rats was (±)doxazosin>(+)doxazosin>>(-)doxazosin. However, the pKB values for inhibiting NA-induced contraction of isolated rat caudal artery were (+)doxazosin (8.995)>(±)doxazosin (8.694)>(-)doxazosin (8.032). The plasma concentrations of (-)doxazosin, (+)doxazosin, and (±)doxazosin were 18.26±3.55, 177.11±20.66, and 113.18±13.21 ng/mL, respectively, 8 h after the last administration of these agents.

CONCLUSION

Long-term treatment with (±)doxazosin produces potent hypotensive action in conscious rats that seems to result from synergic interaction of the two enantiomers.