Efficacy, safety and pharmacokinetics of candesartan cilexetil in hypertensive children from 1 to less than 6 years of age

Oral Gels as an Alternative to Liquid Pediatric Suspensions Compounded from Commercial Tablets

The aim of the study was to propose pharmacy-compounded oral gels as a new and alternative dosage form that is attractive to children as having a better masking taste than syrups and reducing the risk of spilling. The application and physical properties of the gels prepared with cellulose derivatives (hydroxyethylcellulose and carmellose sodium) or carbomers were evaluated. The results of the study showed the most suitable consistency, viscosity, and organoleptic properties for gels prepared with carbomer and cellulose derivatives at concentrations of 0.75% and 2.0%, respectively. The microbial stability of the gels was guaranteed by the use of methylparaben and potassium sorbate. VAL (valsartan) and CC (candesartan cilexetil) tablets, often used off-label in children, were pulverized and suspended in the hydrogel bases, resulting in final drug concentrations of 4 mg/g and 1 mg/g, respectively. There was no significant change in viscosity and consistency parameters when the pulverized tablets were added, and only small changes in viscosity and consistency were observed during 35 days of storage, especially in the gels with sodium carmellose and candesartan. On the basis of the drug assay, an expiry date of 25 °C was recommended: 35 days for valsartan and 14 days for candesartan preparations.

Narrative update of clinical trials with antihypertensive drugs in children and adolescents

INTRODUCTION

To date, our knowledge on antihypertensive pharmacological treatment in children and adolescents is still limited because there are few randomized clinical trials (CTs), hampering appropriate management. The objective was to perform a narrative review of the most relevant aspects of clinical trials carried out in primary and secondary hypertension.

METHODS

Studies published in PubMed with the following descriptors: clinical trial, antihypertensive drug, children, adolescents were selected. A previous Cochrane review of 21 randomized CTs pointed out the difficulty that statistical analysis could not assess heterogeneity because there were not enough data. A more recent meta-analysis, that applied more stringent inclusion criteria and selected 13 CTs, also concluded that heterogeneity, small sample size, and short follow-up time, as well as the absence of studies comparing drugs of different classes, limit the utility.

RESULTS

In the presented narrative review, including 30 studies, there is a paucity of CTs focusing only on children with primary or secondary, mainly renoparenchymal, hypertension. In trials on angiotensin converting enzyme inhibitors (ACEI), angiotensin receptor blockers (ARBs), calcium channel blockers (CCBs) and diuretics, a significant reduction of both SBP and DBP in mixed cohorts of children with primary and secondary hypertension was achieved. However, few studies assessed the effect of antihypertensive drugs on hypertensive organ damage.

CONCLUSIONS

Given the increasing prevalence and undertreatment of hypertension in this age group, innovative solutions including new design, such as 'n-of-1', and optimizing the use of digital health technologies could provide more precise and faster information about the efficacy of each antihypertensive drug class and the potential benefits according to patient characteristics.

Antihypertensives in Children and Adolescents

PURPOSE OF REVIEW

To review target organ outcomes and current pharmacologic treatment options for children and adolescents with hypertension.

RECENT FINDINGS

There is an increased prevalence of pediatric hypertension. Following the 2017 AAP clinical practice guidelines, there is a growing body of literature illustrating the association between pediatric hypertension and end organ damage, though few studies looking at long-term outcomes. There is also new data to support the use of n-of-1 trials to identify the best antihypertensive therapy for an individual. Pediatric hypertension is increasing in prevalence and is associated with end organ damage. Treatment of hypertensive children has been shown to reverse end organ damage. Due to the lack of large, randomized trials assessing antihypertensive classes against one another, n-of-1 studies may serve as a viable and safe option to optimize patient care.

Acute and chronic kidney complications in children with type 1 diabetes mellitus

Children with type 1 diabetes mellitus (T1DM) have an increased risk of developing kidney involvement. Part of the risk establishes at the beginning of T1DM. In fact, up to 65% of children during T1DM onset may experience an acute kidney injury (AKI) which predisposes to the development of a later chronic kidney disease (CKD). The other part of the risk establishes during the following course of T1DM and could be related to a poor glycemic control and the subsequent development of diabetic kidney disease. In this review, we discuss the acute and chronic effects of T1DM on the kidneys, and the implications of these events on the long-term prognosis of kidney function.

The Bioequivalence Between Valsartan Oral Solution and Suspension Formulations Developed for Pediatric Use

The bioequivalence of valsartan 160 mg oral solution compared to suspension was assessed in a single-dose, open-label, randomized, 2-period, 2-way crossover study in 82 healthy adults. The participants were randomly assigned (1:1) to receive a single dose of the solution or suspension formulation in each of the two treatment periods. Serial blood samples for pharmacokinetic evaluation were collected up to 48 hours post-dose. The pharmacokinetic parameters were estimated by noncompartmental methods and analyzed as per bioequivalence criteria of statistical analysis. The peak plasma concentration of valsartan was reached with median time of 1 and 3 hours with solution and suspension formulation, respectively. Compared to suspension formulation, the mean peak plasma concentration with solution formulation was higher by 32% (90%CI, 1.27-1.38) while the geometric mean ratios (1.09) and the associated 90%CIs (1.05-1.13) of both the areas under the concentration time-curves (from time zero to the last quantifiable concentration and from time zero to infinity) were contained in the required range of 0.80 to 1.25. No new safety signals were observed with either of the formulations.

Efficacy and safety of valsartan in children aged 1-5 years with hypertension, with or without chronic kidney disease: a randomized, double-blind study followed by open-label phase

OBJECTIVE

To assess the dose-response relationship for reduction in mean systolic blood pressure (MSBP) with valsartan solution, in young children with hypertension with or without chronic kidney disease (CKD).

METHODS

In this multicenter, randomized, double-blind, double-dummy study, 127 young children aged 1-5 years with hypertension (MSBP ≥95th percentile) were randomized (1:1) to receive valsartan 0.25 or 4 mg/kg/day for 6 weeks, followed by a 20 week open-label phase, where patients received valsartan 1 mg/kg/day for 4 weeks, and then optionally titrated to 2 mg/kg/day or up to 4 mg/kg/day. The primary endpoint was the change in MSBP from baseline at Week 6 during the double-blind phase.

RESULTS

Overall, 120 patients (94.5%) completed the study; 63 had CKD. A clinically and statistically significant reduction in MSBP from baseline to Week 6 was observed with the valsartan 4 mg/kg group compared with the valsartan 0.25 mg/kg group (8.5 vs 4.1 mmHg; p = .0157). A positive dose-response relationship for MSBP reduction was observed between the 0.25 mg/kg and 4 mg/kg groups (p = .0012). In the CKD subgroup, a significant reduction in MSBP was observed with 4 mg/kg (9.2 mmHg) versus 0.25 mg/kg (1.2 mmHg; p = .0096). In the non-CKD subgroup, a numerically greater decrease in MSBP was observed with 4 mg/kg (7.8 mmHg) versus 0.25 mg/kg (6.9 mmHg; p = .6531). Incidence of adverse events was lower with valsartan 4 mg/kg than 0.25 mg/kg (41.9% vs 51.6%) and similar between CKD and non-CKD subgroups (48.4% vs 45.3%) irrespective of dose. Increase in serum potassium (>20% compared to baseline) was observed more frequently in patients with CKD compared to non-CKD patients.

CONCLUSION

Valsartan was efficacious and well tolerated in children 1 to 5 years of age with hypertension, with or without CKD. Clinical trial registration: The study has been registered at ClinicalTrials.gov (Identifier: NCT01617681).

Physiologically based pharmacokinetic modeling of candesartan related to CYP2C9 genetic polymorphism in adult and pediatric patients

Candesartan cilexetil is an angiotensin II receptor blocker and it is widely used to treat hypertension and heart failure. This drug is a prodrug that rapidly converts to candesartan after oral administration. Candesartan is metabolized by cytochrome P450 2C9 (CYP2C9) enzyme or uridine diphosphate glucurinosyltransferase 1A3, or excreted in an unchanged form through urine, biliary tract and feces. We investigated the effect of genetic polymorphism of CYP2C9 enzyme on drug pharmacokinetics using physiologically based pharmacokinetic (PBPK) modeling. In addition, by introducing the age and ethnicity into the model, we developed a model that can propose an appropriate dosage regimen taking into account the individual characteristics of each patient. To evaluate the suitability of the model, the results of a clinical trial on twenty-two healthy Korean subjects and their CYP2C9 genetic polymorphism data was applied. In this study, PK-Sim® was used to develop the PBPK model of candesartan.

Antihypertensive agents: a long way to safe drug prescribing in children

Recently updated clinical guidelines have highlighted the gaps in our understanding and management of pediatric hypertension. With increased recognition and diagnosis of pediatric hypertension, the use of antihypertensive agents is also likely to increase. Drug selection to treat hypertension in the pediatric patient population remains challenging. This is primarily due to a lack of large, well-designed pediatric safety and efficacy trials, limited understanding of pharmacokinetics in children, and unknown risk of prolonged exposure to antihypertensive therapies. With newer legislation providing financial incentives for conducting clinical trials in children, along with publication of pediatric-focused guidelines, literature available for antihypertensive agents in pediatrics has increased over the last 20 years. The objective of this article is to review the literature for safety and efficacy of commonly prescribed antihypertensive agents in pediatrics. Thus far, the most data to support use in children was found for angiotensin-converting enzyme inhibitors (ACE-I), angiotensin receptor blockers (ARB), and calcium channel blockers (CCB). Several gaps were noted in the literature, particularly for beta blockers, vasodilators, and the long-term safety profile of antihypertensive agents in children. Further clinical trials are needed to guide safe and effective prescribing in the pediatric population.

RET Receptor Tyrosine Kinase: Role in Neurodegeneration, Obesity, and Cancer

Rearranged during transfection (RET) is the tyrosine kinase receptor that under normal circumstances interacts with ligand at the cell surface and mediates various essential roles in a variety of cellular processes such as proliferation, differentiation, survival, migration, and metabolism. RET plays a pivotal role in the development of both peripheral and central nervous systems. RET is expressed from early stages of embryogenesis and remains expressed throughout all life stages. Mutations either activating or inhibiting RET result in several aggressive diseases, namely cancer and Hirschsprung disease. However, the physiological ligand-dependent activation of RET receptor is important for the survival and maintenance of several neuronal populations, appetite, and weight gain control, thus providing an opportunity for the development of disease-modifying therapeutics against neurodegeneration and obesity. In this review, we describe the structure of RET, its signaling, and its role in both normal conditions as well as in several disorders. We highlight the differences in the signaling and outcomes of constitutive and ligand-induced RET activation. Finally, we review the data on recently developed small molecular weight RET agonists and their potential for the treatment of various diseases.

Arterial Hypertension in Children

Pharmacological treatment of arterial hypertension in children is mainly based on individual experience, but there is evidence that blocking the angiotensin system reduces systolic and diastolic blood when compared to placebo, and these drugs are safe to use for a short duration, also in children under 6 years of age. Blocking the angiotensin system either by angiotensin-converting enzyme inhibitors or by antagonizing the angiotensin 1 receptor is effective, but did not display a consistent dose-response relationship with escalating doses, but the effective doses are known. Calcium channel antagonists are effective antihypertensives in children, but the evidence is limited. Based on small-sized studies, beta-blockers modestly reduce systolic blood pressure, but have no significant effect on diastolic blood pressure compared to placebo. They act in combination to antagonize reflex tachycardia induced by vasodilators. The most commonly used antihypertensive agents are safe to use in short-term studies.

Research Gaps in Primary Pediatric Hypertension

Hypertension affects >40% of the US population and is a major contributor to cardiovascular-related morbidity and mortality. Although less common among children and adolescents, hypertension affects 1% to 5% of all youth. The 2017 Clinical Practice Guideline for the Diagnosis and Management of High Blood Pressure in Children and Adolescents provided updates and strategies regarding the diagnosis and management of hypertension in youth. Despite this important information, many gaps in knowledge remain, such as the etiology, prevalence, and trends of hypertension; the utility and practicality of ambulatory blood pressure monitoring; practical goals for lifestyle modification that are generalizable; the long-term end-organ impacts of hypertension in youth; and the long-term safety and efficacy of antihypertensive therapy in youth. The Eunice Kennedy Shriver National Institute of Child Health and Human Development, in collaboration with the National Heart, Lung, and Blood Institute and the US Food and Drug Administration, sponsored a workshop of experts to discuss the current state of childhood primary hypertension. We highlight the results of that workshop and aim to (1) provide an overview of current practices related to the diagnosis, management, and treatment of primary pediatric hypertension; (2) identify related research gaps; and (3) propose ways to address existing research gaps.

Pediatric Hypertension

The prevalence of elevated blood pressure and hypertension in children and adolescents has increased over the past decade. This trend is most likely related to increases in primary hypertension associated with increasing obesity rates in children. Lifestyle as well as genetics play a significant role in the development of primary hypertension. Hypertension in children and adolescents is under-recognized and undertreated. The 2017 Revised Clinical Practice Guideline for Screening and Management of High Blood Pressure in Children and Adolescents aimed to create new normative blood pressure tables using data from healthy weight children, meaning between the 5th and 85th percentile per the Centers for Disease Control and Prevention. Another important objective was to simplify normative data to ease screening and detection of elevated blood pressures. The consequences of chronic hypertension are significant, with its major affect being in poor cardiovascular health outcomes both in childhood and early adulthood. Challenges to detection and adequate treatment should be overcome with continued education and awareness to prevent the long-term effects of uncontrolled hypertension that starts in childhood. [Pediatr Ann. 2018;47(12):e499-e503.].

2016 European Society of Hypertension guidelines for the management of high blood pressure in children and adolescents

Increasing prevalence of hypertension (HTN) in children and adolescents has become a significant public health issue driving a considerable amount of research. Aspects discussed in this document include advances in the definition of HTN in 16 year or older, clinical significance of isolated systolic HTN in youth, the importance of out of office and central blood pressure measurement, new risk factors for HTN, methods to assess vascular phenotypes, clustering of cardiovascular risk factors and treatment strategies among others. The recommendations of the present document synthesize a considerable amount of scientific data and clinical experience and represent the best clinical wisdom upon which physicians, nurses and families should base their decisions. In addition, as they call attention to the burden of HTN in children and adolescents, and its contribution to the current epidemic of cardiovascular disease, these guidelines should encourage public policy makers to develop a global effort to improve identification and treatment of high blood pressure among children and adolescents.

Clinical Practice Guideline for Screening and Management of High Blood Pressure in Children and Adolescents

These pediatric hypertension guidelines are an update to the 2004 "Fourth Report on the Diagnosis, Evaluation, and Treatment of High Blood Pressure in Children and Adolescents." Significant changes in these guidelines include (1) the replacement of the term "prehypertension" with the term "elevated blood pressure," (2) new normative pediatric blood pressure (BP) tables based on normal-weight children, (3) a simplified screening table for identifying BPs needing further evaluation, (4) a simplified BP classification in adolescents ≥13 years of age that aligns with the forthcoming American Heart Association and American College of Cardiology adult BP guidelines, (5) a more limited recommendation to perform screening BP measurements only at preventive care visits, (6) streamlined recommendations on the initial evaluation and management of abnormal BPs, (7) an expanded role for ambulatory BP monitoring in the diagnosis and management of pediatric hypertension, and (8) revised recommendations on when to perform echocardiography in the evaluation of newly diagnosed hypertensive pediatric patients (generally only before medication initiation), along with a revised definition of left ventricular hypertrophy. These guidelines include 30 Key Action Statements and 27 additional recommendations derived from a comprehensive review of almost 15 000 published articles between January 2004 and July 2016. Each Key Action Statement includes level of evidence, benefit-harm relationship, and strength of recommendation. This clinical practice guideline, endorsed by the American Heart Association, is intended to foster a patient- and family-centered approach to care, reduce unnecessary and costly medical interventions, improve patient diagnoses and outcomes, support implementation, and provide direction for future research.

Oral drug absorption in pediatrics: the intestinal wall, its developmental changes and current tools for predictions

The dissolution, intestinal absorption and presystemic metabolism of a drug depend on its physicochemical characteristics but also on numerous physiological (e.g. gastrointestinal pH, volume, transit time, morphology) and biochemical factors (e.g. luminal enzymes and flora, intestinal wall enzymes and transporters). Over the past decade, evidence has accumulated indicating that these factors may differ in children and adults resulting in age-related changes in drug exposure and drug response. Thus, drug dosage may require adjustment for the pediatric population to ensure the desired therapeutic outcome and to avoid side-effects. Although tremendous progress has been made in understanding the effects of age on intestinal physiology and function, significant knowledge gaps remain. Studying and predicting pharmacokinetics in pediatric patients remains challenging due to ethical concerns associated with clinical trials in this vulnerable population, and because of the paucity of predictive in vitro and in vivo animal assays. This review details the current knowledge related to developmental changes determining intestinal drug absorption and pre-systemic metabolism. Supporting experimental approaches as well as physiologically based pharmacokinetic modeling are also discussed together with their limitations and challenges. Copyright © 2016 John Wiley & Sons, Ltd.

Pharmacologic Treatment of Pediatric Hypertension

Prevalence of hypertension is increasing in children and adolescents. Uncontrolled hypertension in children not only causes end organ damage but also increases the risk of adult hypertension and cardiovascular disease. Clinical trials have proven efficacy of antihypertensive medications in children. These medications are well tolerated by children with acceptable safety profile. The choice of agent is usually driven by underlying etiology of hypertension, profile of its side effects, and clinician's preference. This article will review currently available pediatric data on mechanism of action, common adverse effects, pediatric indication, recent clinical trial, and newer drugs in the common classes of antihypertensive medications.

Pharmacologic Management of Pediatric Hypertension

Hypertension in children is common, and the prevalence of primary hypertension is increasing with the obesity epidemic and changing dietary choices. Careful measurement of blood pressure is important to correctly diagnose hypertension, as many factors can lead to inaccurate blood pressure measurement. Hypertension is diagnosed based on comparison of age-, sex-, and height-based norms with the average systolic and diastolic blood pressures on three separate occasions. In the absence of hypertensive target organ damage (TOD), stage I hypertension is managed first by diet and exercise, with the addition of drug therapy if this fails. First-line treatment of stage I hypertension with TOD and stage II hypertension includes both lifestyle changes and medications. First-line agents include angiotensin-converting enzyme (ACE) inhibitors, thiazide diuretics, and calcium-channel blockers. Hypertensive emergency with end-organ effects requires immediate modest blood pressure reduction to alleviate symptoms. This is usually accomplished with IV medications. Long-term reduction in blood pressure to normal levels is accomplished gradually. Specific medication choice for outpatient hypertension management is determined by the underlying cause of hypertension and the comparative adverse effect profiles, along with practical considerations such as cost and frequency of administration. Antihypertensive medication is initiated at a starting dose and can be gradually increased to effect. If ineffective at the recommended maximum dose, an additional medication with a complementary mechanism of action can be added.

Single-dose pharmacokinetics and safety of azilsartan medoxomil in children and adolescents with hypertension as compared to healthy adults

PURPOSE

This open-label, multicenter, single-dose study characterized the pharmacokinetics and short-term safety of azilsartan medoxomil (AZL-M) in hypertensive pediatric subjects (12-16 years [cohort 1a; n = 9]; 6-11 years [cohort 2; n = 8]; 4-5 years [cohort 3; n = 3]).

METHODS

Model-based simulations were performed to guide dosing, especially in 1-5-year olds, who were difficult to enroll. AZL-M was dosed according to body weight (20-60-mg tablet, cohorts 1a and 2; 0.66 mg/kg granule suspension, cohort 3). In cohort 1, gender-matched healthy adults (cohort 1b; n = 9) received AZL-M 80 mg.

RESULTS

Exposure to AZL (active moiety of AZL-M), measured by dose-/body weight-normalized C max and AUC0-∞, was ∼15-30 % lower in pediatric subjects versus adults. In simulations, exposure with 0.66 mg/kg AZL-M in pediatric subjects weighing 8-25 kg approximated to AZL-M 40 mg (typical starting dose) in adults. The simulations suggest that 25-50-kg subjects require half the adult dose (10-40 mg), whereas 50-100-kg subjects can use the same dosing as adults. Adverse events were mild in intensity, apart from one moderate event (migraine).

CONCLUSIONS

This dosing strategy should be safe in pediatric patients, as AZL exposure would not exceed that seen in adults with the highest approved AZL-M dose (80 mg).

[Is it ethically acceptable to invite a pregnant woman to enroll in a clinical trial with Tdap if it could entail not being vaccinated with Tdap before delivery?]

Pertussis incidence has increased in recent years, especially among infants aged <2months. A number of Spanish regions have started a vaccination program with Tdap vaccine to all pregnant women in the third trimester of pregnancy. An observational study has shown that this strategy reduces the number of cases of pertussis by 90% in infants aged <2months. Mathematical models showed that a cocooning strategy (i.e. vaccination of the mother at immediate postpartum, and other adults and adolescents who have close contact with the newborn and caregivers) will reduce the incidence of pertussis by 70% in infants aged <2months. It is intended to conduct a clinical trial in which 340 pregnant women will receive Tdap vaccine, whereas another 340 pregnant woman will be vaccinated soon after delivery. Vaccination with Tdap will be offered to all partners and caregivers of the newborn. After assessing both the ethical and scientific reasons supporting the trial, it is concluded that it is ethically and legally acceptable to invite pregnant women living in communities where Tdap vaccination has been implemented to participate in the trial.

Pharmacological interventions for hypertension in children

BACKGROUND

Hypertension is a major risk factor for stroke, coronary artery disease and kidney damage in adults. There is a paucity of data on the long-term sequelae of persistent hypertension in children, but it is known that children with hypertension have evidence of end organ damage and are at risk of hypertension into adulthood. The prevalence of hypertension in children is rising, most likely due to a concurrent rise in obesity rates. In children with hypertension, non-pharmacological measures are often recommended as first-line therapy, but a significant proportion of children will eventually require pharmacological treatment to reduce blood pressure, especially those with evidence of end organ damage at presentation or during follow-up. A systematic review of the effects of antihypertensive agents in children has not previously been conducted.

OBJECTIVES

To determine the dose-related effects of different classes of antihypertensive medications, as monotherapy compared to placebo; as combination therapy compared to placebo or a single medication; or in comparisons of various doses within the same class, on systolic or diastolic blood pressure (or both) in children with hypertension.

SEARCH METHODS

We searched the Cochrane Hypertension Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (2013, Issue 9), Ovid MEDLINE (1946 to October 2013), Ovid EMBASE (1974 to October 2013) and bibliographic citations.

SELECTION CRITERIA

The selection criteria were deliberately broad due to there being few clinical trials in children. We included randomised controlled trials (RCTs) of at least two weeks duration comparing antihypertensive agents either as monotherapy or combination therapy with either placebo or another medication, or comparing different doses of the same medication, in children with hypertension. Hypertension was defined as an average (over a minimum of three readings) systolic or diastolic blood pressure (or both) on the 95(th) percentile or above for age, height and gender.

DATA COLLECTION AND ANALYSIS

Two authors independently selected relevant studies, extracted data and assessed risk of bias. We summarised data, where possible, using a random-effects model. Formal assessment of heterogeneity was not possible because of insufficient data.

MAIN RESULTS

A total of 21 trials evaluated antihypertensive medications of various drug classes in 3454 hypertensive children with periods of follow-up ranging from three to 24 weeks. There were five RCTs comparing an antihypertensive drug directly with placebo, 12 dose-finding trials, two trials comparing calcium channel blockers with angiotensin receptor blockers, one trial comparing a centrally acting alpha blocker with a diuretic and one trial comparing an angiotensin-converting enzyme inhibitor with an angiotensin receptor blocker. No randomised trial was identified that evaluated the effectiveness of antihypertensive medications on target end organ damage. The trials were of variable quality and most were funded by pharmaceutical companies. Among the angiotensin receptor blockers, candesartan (one trial, n = 240), when compared to placebo, reduced systolic blood pressure by 6.50 mmHg (95% confidence interval (CI) -9.44 to -3.56) and diastolic blood pressure by 5.50 mmHg (95% CI -9.62 to -1.38) (low-quality evidence). High dose telmisartan (one trial, n = 76), when compared to placebo, reduced systolic blood pressure by -8.50 (95% CI -13.79 to -3.21) but not diastolic blood pressure (-4.80, 95% CI -9.50 to 0.10) (low-quality evidence). Beta blocker (metoprolol, one trial, n = 140), when compared with placebo , significantly reduced systolic blood pressure by 4.20 mmHg (95% CI -8.12 to -0.28) but not diastolic blood pressure (-3.20 mmHg 95% CI -7.12 to 0.72) (low-quality evidence). Beta blocker/diuretic combination (Bisoprolol/hydrochlorothiazide, one trial, n = 94)when compared with placebo , did not result in a significant reduction in systolic blood pressure (-4.0 mmHg, 95% CI -8.99 to -0.19) but did have an effect on diastolic blood pressure (-4.50 mmHg, 95% CI -8.26 to -0.74) (low-quality evidence). Calcium channel blocker (extended-release felodipine,one trial, n = 133) was not effective in reducing systolic blood pressure (-0.62 mmHg, 95% CI -2.97 to 1.73) or diastolic blood pressure (-1.86 mmHg, 95% CI -5.23 to 1.51) when compared with placebo. Further, there was no consistent dose response observed among any of the drug classes. The adverse events associated with the antihypertensive agents were mostly minor and included headaches, dizziness and upper respiratory infections.

AUTHORS' CONCLUSIONS

Overall, there are sparse data informing the use of antihypertensive agents in children, with outcomes reported limited to blood pressure and not end organ damage. The most data are available for candesartan, for which there is low-quality evidence of a modest lowering effect on blood pressure. We did not find evidence of a consistent dose response relationship for escalating doses of angiotensin receptor blockers, calcium channel blockers or angiotensin-converting enzyme inhibitors. All agents appear safe, at least in the short term.

Pharmacological interventions for hypertension in children

BACKGROUND

Hypertension is a major risk factor for stroke, coronary artery disease and kidney damage in adults. There is a paucity of data on the long-term sequelae of persistent hypertension in children, but it is known that children with hypertension have evidence of end organ damage and are at risk of hypertension into adulthood. The prevalence of hypertension in children is rising, most likely due to a concurrent rise in obesity rates. In children with hypertension, non-pharmacological measures are often recommended as first-line therapy, but a significant proportion of children will eventually require pharmacological treatment to reduce blood pressure, especially those with evidence of end organ damage at presentation or during follow-up. A systematic review of the effects of antihypertensive agents in children has not previously been conducted.

OBJECTIVES

To determine the dose-related effects of different classes of antihypertensive medications, as monotherapy compared to placebo; as combination therapy compared to placebo or a single medication; or in comparisons of various doses within the same class, on systolic or diastolic blood pressure (or both) in children with hypertension.

SEARCH METHODS

We searched the Cochrane Hypertension Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (2013, Issue 9), Ovid MEDLINE (1946 to October 2013), Ovid EMBASE (1974 to October 2013) and bibliographic citations.

SELECTION CRITERIA

The selection criteria were deliberately broad due to there being few clinical trials in children. We included randomised controlled trials (RCTs) of at least two weeks duration comparing antihypertensive agents either as monotherapy or combination therapy with either placebo or another medication, or comparing different doses of the same medication, in children with hypertension. Hypertension was defined as an average (over a minimum of three readings) systolic or diastolic blood pressure (or both) on the 95(th) percentile or above for age, height and gender. 

DATA COLLECTION AND ANALYSIS

Two authors independently selected relevant studies, extracted data and assessed risk of bias. We summarised data, where possible, using a random-effects model. Formal assessment of heterogeneity was not possible because of insufficient data.

MAIN RESULTS

A total of 21 trials evaluated antihypertensive medications of various drug classes in 3454 hypertensive children with periods of follow-up ranging from three to 24 weeks. There were five RCTs comparing an antihypertensive drug directly with placebo, 12 dose-finding trials, two trials comparing calcium channel blockers with angiotensin receptor blockers, one trial comparing a centrally acting alpha blocker with a diuretic and one trial comparing an angiotensin-converting enzyme inhibitor with an angiotensin receptor blocker. No randomised trial was identified that evaluated the effectiveness of antihypertensive medications on target end organ damage. The trials were of variable quality and most were funded by pharmaceutical companies.Among the angiotensin receptor blockers, candesartan (one trial, n = 240), when compared to placebo, reduced systolic blood pressure by 6.50 mmHg (95% confidence interval (CI) -9.44 to -3.56) and diastolic blood pressure by 5.50 mmHg (95% CI -9.62 to -1.38) (low-quality evidence). High dose telmisartan (one trial, n = 76), when compared to placebo, reduced systolic blood pressure by -8.50 (95% CI -13.79 to -3.21) but not diastolic blood pressure (-4.80, 95% CI -9.50 to 0.10) (low-quality evidence). Beta blocker (metoprolol, one trial, n = 140), when compared with placebo , significantly reduced systolic blood pressure by 4.20 mmHg (95% CI -8.12 to -0.28) but not diastolic blood pressure (-3.20 mmHg 95% CI -7.12 to 0.72) (low-quality evidence). Beta blocker/diuretic combination (Bisoprolol/hydrochlorothiazide, one trial, n = 94)when compared with placebo , did not result in a significant reduction in systolic blood pressure (-4.0 mmHg, 95% CI -8.99 to -0.19) but did have an effect on diastolic blood pressure (-4.50 mmHg, 95% CI -8.26 to -0.74) (low-quality evidence). Calcium channel blocker (extended-release felodipine,one trial, n = 133) was not effective in reducing systolic blood pressure (-0.62 mmHg, 95% CI -2.97 to 1.73) or diastolic blood pressure (-1.86 mmHg, 95% CI -5.23 to 1.51) when compared with placebo. Further, there was no consistent dose response observed among any of the drug classes. The adverse events associated with the antihypertensive agents were mostly minor and included headaches, dizziness and upper respiratory infections.

AUTHORS' CONCLUSIONS

Overall, there are sparse data informing the use of antihypertensive agents in children, with outcomes reported limited to blood pressure and not end organ damage. The most data are available for candesartan, for which there is low-quality evidence of a modest lowering effect on blood pressure. We did not find evidence of a consistent dose response relationship for escalating doses of angiotensin receptor blockers, calcium channel blockers or angiotensin-converting enzyme inhibitors. All agents appear safe, at least in the short term.

Primary hypertension in children and adolescents is an immuno-metabolic disease with hemodynamic consequences

With the rise in obesity epidemic primary hypertension (PH) is now one of the most common chronic diseases in adolescence. In contrast to hypertensive adults, hypertensive children usually are not exposed to other comorbidities such as diabetes, chronic kidney disease and atherosclerosis. Thus, PH in children and adolescents can be treated as the early stage of development of cardiovascular disease. There is increasing amount of data indicating that PH is not only hemodynamic phenomenon but a complex syndrome involving disturbed activity of sympathetic nervous system, metabolic abnormalities and activation of innate and adaptive immune system. We discuss results of the studies on clinical, metabolic and immunological phenotype of hypertensive children, associations between metabolic and immunological abnormalities with target organ damage and results of antihypertensive treatment.

A systematic comparison of the properties of clinically used angiotensin II type 1 receptor antagonists

Angiotensin II type 1 receptor antagonists (ARBs) have become an important drug class in the treatment of hypertension and heart failure and the protection from diabetic nephropathy. Eight ARBs are clinically available [azilsartan, candesartan, eprosartan, irbesartan, losartan, olmesartan, telmisartan, valsartan]. Azilsartan (in some countries), candesartan, and olmesartan are orally administered as prodrugs, whereas the blocking action of some is mediated through active metabolites. On the basis of their chemical structures, ARBs use different binding pockets in the receptor, which are associated with differences in dissociation times and, in most cases, apparently insurmountable antagonism. The physicochemical differences between ARBs also manifest in different tissue penetration, including passage through the blood-brain barrier. Differences in binding mode and tissue penetration are also associated with differences in pharmacokinetic profile, particularly duration of action. Although generally highly specific for angiotensin II type 1 receptors, some ARBs, particularly telmisartan, are partial agonists at peroxisome proliferator-activated receptor-γ. All of these properties are comprehensively reviewed in this article. Although there is general consensus that a continuous receptor blockade over a 24-hour period is desirable, the clinical relevance of other pharmacological differences between individual ARBs remains to be assessed.

Pharmacokinetics of olmesartan medoxomil in pediatric patients with hypertension

BACKGROUND

The prevalence and importance of hypertension in younger patients is becoming increasingly recognized; however, only a limited number of clinical trials have been conducted in the pediatric population.

OBJECTIVE

The aim of this study was to characterize the pharmacokinetics and short-term safety of olmesartan medoxomil in children and adolescents with hypertension.

METHODS

An open-label, multicenter, single-dose study was conducted in children and adolescents aged 12 months-16 years who were receiving treatment for hypertension or, if not currently treated for hypertension, had either a systolic blood pressure (SBP) or diastolic blood pressure (DBP).≥95th percentile, or SBP or DBP ≥90th percentile if diabetic or with a family history of hypertension. Patients were stratified by age: 12-23 months (Group 1; none enrolled), 2-5 years (Group 2; n = 4), 6-12 years (Group 3; n = 10), and 13-16 years (Group 4; n = 10). All patients received a single oral dose of olmesartan medoxomil based on the individual's age and bodyweight. Patients aged <6 years received an oral suspension of olmesartan medoxomil at a dose of 0.3 mg/kg of bodyweight (not to exceed 20 mg), those aged ≥6 years who weighed ≥35 kg received olmesartan medoxomil 40 mg tablets, and those who weighed <35 kg received olmesartan medoxomil 20 mg tablets.

RESULTS

In Groups 2, 3, and 4, the weight-adjusted apparent total body clearance (CL/F) of olmesartan medoxomil was 0.100 ± 0.034, 0.062 ± 0.020, and 0.072 ± 0.022 L/h/kg, respectively, and the weight-adjusted apparent volume of distribution (Vd/F) was 0.32 ± 0.16, 0.33 ± 0.14, and 0.49 ± 0.23 L/kg, respectively. CL/F and Vd/F in Groups 3 and 4 were not significantly different. Statistical comparisons between Groups 3 or 4 and Group 2 were not performed due to the small sample size of Group 2 (n = 4). Plasma elimination half-life and time to maximum plasma concentration were similar across the three groups. In Groups 3 and 4, considerable interindividual variability was seen in maximum plasma concentration (C(max)), area under the curve (AUC) from time zero to the last measurable concentration, and apparent clearance, with AUC and C(max) approximately 30% greater in Group 3. Four of 24 (16.7%) patients experienced treatment-emergent adverse events that were all mild in severity and considered not drug-related. No deaths, serious adverse events, or discontinuations due to adverse events occurred in the study.

CONCLUSIONS

Olmesartan medoxomil was well tolerated and demonstrated a pharmacokinetic profile in pediatric patients similar to that of adults when adjusted for body size.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT00151814

Antihypertensive drug use by children: are the drugs labeled and indicated?

As a result of the Food and Drug Administration (FDA) Modernization Act and the Best Pharmaceuticals for Children Act, the number of medications with FDA-approved pediatric labeling has increased. To assess the success of these initiatives, we examined whether antihypertensive drugs used by children with hypertension in 2008 had FDA-approved pediatric labeling and indications. Using a nationwide commercial insurer database, 2915 children with primary (n=2607) and secondary (n=308) hypertension were identified. Drug user rate and days of supply were calculated from pharmacy claims. Drugs were categorized based on pediatric labeling and indication and whether they were recommended for pediatric use. Antihypertensive drugs were used by 889 (34%) children with primary hypertension and 200 children (65%) with secondary hypertension. User rates were 44.3% in hypertensive children younger than 6 years, 30.9% in those 6 years to older than 12 years, and 38.1% in those 12 years to older than 18 years. Seven percent of drugs were neither labeled for pediatric use nor considered recommended for use in children. In children younger than 6 years, 29% of drugs used were not indicated for use in that age group. Despite recent legislative initiatives, many drugs used by hypertensive children still lack pediatric labeling. Additional efforts are needed to close the gap between the availability of drugs that are labeled and indicated for pediatric use and actual drug usage in children.

Efficacy and safety of valsartan compared to enalapril in hypertensive children: a 12-week, randomized, double-blind, parallel-group study

OBJECTIVE

This study compares efficacy and safety of valsartan with enalapril in hypertensive children aged 6-17 years.

METHOD

This was a 12-week, randomized, double-blind, parallel-group, active-controlled study. After a single-blind placebo run-in period (4-28 days), patients with mean sitting systolic blood pressure (BP) (MSSBP) at least 95th percentile for age, gender, and height were randomized to receive half the assigned dose for first week, and force-titrated to full dose for 11 weeks (≥18 to <35 kg - valsartan: 80 mg, enalapril: 10 mg; ≥35 to <80 kg - valsartan: 160 mg, enalapril: 20 mg; ≥80 to ≤160 kg - valsartan: 320 mg, enalapril: 40 mg). The primary efficacy variable was changed from baseline in MSSBP to show noninferiority of valsartan to enalapril. Other efficacy variables were changed from baseline in MSDBP, SBP control rate, and 24-h ambulatory BP parameters.

RESULTS

Of 300 randomized patients, 281 (94%) completed the study. At week 12, MSSBP reductions were similar for valsartan and enalapril (primary endpoint of noninferiority, P < 0.0001). Least square mean BP reductions from baseline of -15.4/-9.4 mmHg were observed for valsartan compared with -14.1/-8.5 mmHg for enalapril. A similar proportion of patients achieved SBP control (valsartan: 67%; enalapril: 70%). In the subset of patients who underwent ambulatory BP assessments, valsartan provided greater reductions than enalapril in mean 24-h SBP (valsartan: -9.8 mmHg, enalapril: -7.2 mmHg: P = 0.03). The overall incidence of AEs was similar (valsartan 60%, enalapril 58%) with headache, cough, and nasopharyngitis reported most frequently.

CONCLUSIONS

Valsartan and enalapril provided comparable BP reductions and effective BP control and were well tolerated in hypertensive children aged 6-17 years.

Management of hypertension in the young: role of antihypertensive medications

Traditionally, antihypertensive medications were used in few children or adolescents, usually just those with underlying renal or other organ system disease. However, with recent data suggesting that the incidence of primary hypertension may be increasing in the young, it is possible that more children and adolescents will be prescribed antihypertensive agents. This article will review currently available pediatric data on the use of calcium channel blockers, agents affecting the renin-angiotensin-aldosterone system and other classes of antihypertensive medications in children, highlighting appropriate indications and safety considerations. Guidelines for use of antihypertensive medications, including choice of initial agent and how to prescribe appropriately, will be presented.

Differential clinical profile of candesartan compared to other angiotensin receptor blockers

The advantages of blood pressure (BP) control on the risks of heart failure and stroke are well established. The renin-angiotensin system plays an important role in volume homeostasis and BP regulation and is a target for several groups of antihypertensive drugs. Angiotensin II receptor blockers represent a major class of antihypertensive compounds. Candesartan cilexetil is an angiotensin II type 1 (AT[1]) receptor antagonist (angiotensin receptor blocker [ARB]) that inhibits the actions of angiotensin II on the renin-angiotensin-aldosterone system. Oral candesartan 8–32 mg once daily is recommended for the treatment of adult patients with hypertension. Clinical trials have demonstrated that candesartan cilexetil is an effective agent in reducing the risk of cardiovascular mortality, stroke, heart failure, arterial stiffness, renal failure, retinopathy, and migraine in different populations of adult patients including patients with coexisting type 2 diabetes, metabolic syndrome, or kidney impairment. Clinical evidence confirmed that candesartan cilexetil provides better antihypertensive efficacy than losartan and is at least as effective as telmisartan and valsartan. Candesartan cilexetil, one of the current market leaders in BP treatment, is a highly selective compound with high potency, a long duration of action, and a tolerability profile similar to placebo. The most important and recent data from clinical trials regarding candesartan cilexetil will be reviewed in this article.

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.

Proteinuria in special populations: pregnant women and children

Proteinuria is the hallmark of glomerular kidney disease. It is used diagnostically to follow disease progression and to determine response to therapy. Thus, it is necessary to have an understanding of the mechanisms of proteinuria and the limitations to its accurate assessment in special populations. In this article, we review 2 special populations--pregnant women and children--providing insight into their unique circumstances that require consideration when assessing proteinuria.

Candesartan cilexetil: in children and adolescents aged 1 to <17 years with hypertension

Candesartan cilexetil is the orally administered prodrug of candesartan, an angiotensin II subtype 1 receptor antagonist. The pharmacokinetics (area under the plasma concentration-time curve and maximum plasma concentration) of candesartan do not appear to be affected by age, sex, or weight, with a similar exposure observed in children aged 1 to <6 years or >6 years and adults. Therapy with candesartan cilexetil 0.05, 0.20, and 0.40 mg/kg/day for 4 weeks was effective in the treatment of hypertension in children aged 1 to <6 years, inducing significant dose-dependent reductions from baseline in sitting SBP (SSBP) [primary endpoint] and sitting DBP (SDBP) in the double-blind phase of a randomized, parallel-group, multinational, dose-ranging clinical study. The criteria for antihypertensive response (SBP and DBP values that were less than the 95th percentile) were met by 28-66% of patients. The beneficial antihypertensive effects of candesartan cilexetil therapy were sustained for up to 160 weeks. No significant difference from zero in the slope of the placebo-adjusted change in SSBP (primary endpoint) and SDBP was observed across the three candesartan cilexetil treatment groups (candesartan cilexetil 2, 8, or 16 mg/day in patients weighing <50 kg and candesartan cilexetil 4, 16, or 32 mg/day in patients weighing ≥50 kg) during the double-blind phase of a randomized, double-blind, parallel-group, placebo-controlled, multinational, dose-ranging study in children and adolescents aged 6 to <17 years. Nonetheless, candesartan cilexetil demonstrated significantly greater changes from baseline to the end of the double-blind phase than placebo in SSBP and SDBP, with a significantly higher proportion of patients receiving candesartan cilexetil meeting the criteria for antihypertensive response than those receiving placebo. Antihypertensive response rates were sustained for 52 weeks. Candesartan cilexetil therapy for up to 160 weeks was generally well tolerated in clinical studies in children and adolescents aged 1 to <17 years with hypertension.