Low-dose thiazide diuretics in children with idiopathic renal hypercalciuria

Comparison of the Effect of Hydroalcholic Extract of Alhagi maurorum and Hydrochlorothiazide on Excretion of 4-10 mm Kidney and Ureteral Stones in Adults: A Randomized Prospective Study

Objective

The prevalence of kidney stones and their complications is high. The review of the literature showed the therapeutic effects of Alhagi maurorum extract on urinary tract stones. This study reviewed the Alhagi plant's hydroalcholic extract's effect on eliminating kidney and ureteral stones compared to hydrochlorothiazide.

Materials and Methods

In this randomized prospective study, from March 2019 to September 2021, 80 patients over 18 years of age with kidney stones in the upper ureter with a size of 4-10 mm were divided into two groups based on the block random allocation method. The first group received hydrochlorothiazide tablets (50 mg), and the second group received 1 gram/day of the hydroalcholic areal extract of Alhagi maurorum in a two-divided capsule. The mean size and number of stones, renal function tests, and side effects were checked and compared in both groups before and after the study.

Results

Mean age, sex, serum urea level (P=0.351), serum creatinine (P=0.393), stone size (P=0178), and the number of stones (P=0.052) before intervention were similar. After intervention, the size and number of stones diminished, up to 70% in both groups. However, there was not a statistically significant difference between the two groups.

Conclusion

The study showed that Alhagi maurorum is as effective as hydrochlorothiazide in treatment of kidney and ureteral stones with no significant complications and is promising.

Targeting Calcineurin Inhibitor-Induced Arterial Hypertension in Liver Transplanted Children Using Hydrochlorothiazide

OBJECTIVE

Arterial hypertension (AH) is the most common toxic effect of calcineurin inhibitor (CNI)-based immunosuppression in children after liver transplantation (LT). Activation of the renal sodium chloride cotransporter (NCC) by CNIs has been described as a major cause of CNI-induced AH. Thiazides, for example, hydrochlorothiazide (HCTZ), can selectively block the NCC and may ameliorate CNI-induced AH after pediatric LT.

METHODS

From 2005 thru 2015 we conducted a retrospective, single-center analysis of blood pressure in 2 pediatric cohorts (each n = 33) with or without HCTZ in their first year after LT. All patients received CNI-based immunosuppression. According to AAP guidelines, AH was defined as stage 1 and stage 2. Cohort 1 received an HCTZ-containing regimen to target the CNI-induced effect on the NCC, leading to AH. Cohort 2 received standard antihypertensive therapy without HCTZ.

RESULTS

In children who have undergone LT and been treated with CNI, AH overall was observed less frequently in cohort 1 vs cohort 2 (31% vs 44%; ns). Moreover, severe AH (stage 2) was significantly lower in cohort 1 vs 2 (1% vs 18%; p < 0.001). Multivariate analysis revealed HCTZ as the only significant factor with a protective effect on occurrence of severe stage 2 AH. While monitoring safety and tolerability, mild asymptomatic hypokalemia was the only adverse effect observed more frequently in cohort 1 vs 2 (27% vs 3%; p = 0.013).

CONCLUSIONS

Targeting NCC by HCTZ significantly improved control of severe CNI-induced AH and was well tolerated in children who underwent LT. This effect may reduce the risk of long-term end-organ damage and improve quality of life.

Molecular mechanisms altering tubular calcium reabsorption

The majority of calcium filtered by the glomerulus is reabsorbed along the nephron. Most is reabsorbed from the proximal tubule (> 60%) via a paracellular pathway composed of the tight junction proteins claudins-2 and -12, a process driven by sodium and consequently water reabsorption. The thick ascending limb reabsorbs the next greatest amount of calcium (20-25%), also by a paracellular pathway composed of claudins-16 and -19. This pathway is regulated by the CaSR, whose activity increases the expression of claudin-14, a protein that blocks paracellular calcium reabsorption. The fine tuning of urinary calcium excretion occurs in the distal convoluted and connecting tubule by a transcellular pathway composed of the apical calcium channel TRPV5, the calcium shuttling protein calbindin-D_28K and the basolateral proteins PMCA1b and the sodium calcium exchanger, NCX. Not surprisingly, mutations in a subset of these genes cause monogenic disorders with hypercalciuria as a part of the phenotype. More commonly, "idiopathic" hypercalciuria is encountered clinically with genetic variations in CLDN14, the CASR and TRPV5 associating with kidney stones and increased urinary calcium excretion. An understanding of the molecular pathways conferring kidney tubular calcium reabsorption is employed in this review to help explain how dietary and medical interventions for this disorder lower urinary calcium excretion.

The current status of preventive measures for urinary calculi in children

Urological calculus is a common disease in urology. Urological calculi are generally more common in adults but have become more common in children in recent years. Most existing studies focus on the prevention of urinary calculi in adults; there are relatively few articles on calculi in children. Reported preventive measures are not comprehensive enough, while the latest research progress has not been updated. The pathogenesis and preventive measures associated with urinary calculi have been the focus of research, but many preventive measures still need further clarification. This article reviews the progress on preventive measures for urinary calculi in children.

Prevention of recurrent urinary stone disease

PURPOSE OF REVIEW

Urinary stone disease (USD) is increasing in prevalence and recurrence is common. In pediatrics, most stones are composed primarily of calcium with the highest incidence observed in adolescents. Given the morbidity associated with USD, an in depth review of current management strategies is of paramount importance to highlight the data supporting the recommended treatments and the knowledge gaps which still exist.

RECENT FINDINGS

Several interventions for the management of recurrent calcium USD in children have been recommended based on primarily adult studies. These interventions include modification of diet and fluid intake in addition to the utilization of medications such as thiazide diuretics and citrates when supportive care is inadequate. Overall there is conflicting data in the adult literature which is further complicated by our attempts to extrapolate these data to children.

SUMMARY

Based on the currently available literature the management of USD in pediatrics should be individualized to each patient and focused on the particular metabolic risk factors that are identified during the course of their evaluation. Several interventions may be required or trialed in a particular patient to show an effect. Well designed trials to assess the efficacy of each intervention in the pediatric population are needed.

Medical and dietary interventions for preventing recurrent urinary stones in children

BACKGROUND

Nephrolithiasis, or urinary stone disease, in children causes significant morbidity, and is increasing in prevalence in the North American population. Therefore, medical and dietary interventions (MDI) for recurrent urinary stones in children are poised to gain increasing importance in the clinical armamentarium.

OBJECTIVES

To assess the effects of medical and dietary interventions (MDI) for the prevention of idiopathic urinary stones in children aged from one to 18 years.

SEARCH METHODS

We searched multiple databases using search terms relevant to this review, including studies identified from the Cochrane Central Register of Controlled Trials (CENTRAL, 2017, Issue 1), MEDLINE OvidSP (1946 to 14 February 2017), Embase OvidSP (1980 to 14 February 2017), International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov. Additionally, we handsearched renal-related journals and the proceedings of major renal conferences, and reviewed weekly current awareness alerts for selected renal journals. The date of the last search was 14 February 2017. There were no language restrictions.

SELECTION CRITERIA

Randomized controlled trials of at least one year of MDI versus control for prevention of recurrent idiopathic (non-syndromic) nephrolithiasis in children.

DATA COLLECTION AND ANALYSIS

We used standard methodologic procedures expected by Cochrane. Titles and abstracts were identified by search criteria and then screened for relevance, and then data extraction and risk of bias assessment were carried out. We assessed the quality of evidence using GRADE.

MAIN RESULTS

The search identified one study of 125 children (72 boys and 53 girls) with calcium-containing idiopathic nephrolithiasis and normal renal morphology following initial treatment with shockwave lithotripsy (SWL). Patients were randomized to oral potassium citrate 1 mEq/kg per day for 12 months versus no specific medication or preventive measure with results reported for a total of 96 patients (48 per group). This included children who were stone-free (n = 52) or had residual stone fragments (n = 44) following SWL. Primary outcomes:Medical therapy may lower rates of stone recurrence with a risk ratio (RR) of 0.19 (95% confidence interval (CI) 0.06 to 0.60; low quality evidence). This corresponds to 270 fewer stone recurrences per 1000 (133 fewer to 313 fewer) children. We downgraded the quality of evidence by two levels for very serious study limitations related to unclear allocation concealment (selection bias) and a high risk of performance, detection and attrition bias. While the data for adverse events were incomplete, they reported that six of 48 (12.5%) children receiving potassium citrate left the trial because of adverse effects. This corresponds to a RR of 13.0 (95% CI 0.75 to 224.53; very low quality evidence); an absolute effect size estimate could not be generated. We downgraded the quality of evidence for study limitations and imprecision.We found no information on retreatment rates.

SECONDARY OUTCOMES

We found no evidence on serum electrolytes, 24-hour urine collection parameters or time to new stone formation.We were unable to perform any preplanned secondary analyses.

AUTHORS' CONCLUSIONS

Oral potassium citrate supplementation may reduce recurrent calcium urinary stone formation in children following SWL; however, our confidence in this finding is limited. A substantial number of children stopped the medication due to adverse events. There is no trial evidence on retreatment rates. There is a critical need for additional well-designed trials in children with nephrolithiasis.

Kidney Stone Recurrence among Children and Adolescents

PURPOSE

Kidney stone disease has become increasingly common during childhood and adolescence. However, the rate of symptomatic kidney stone recurrence for pediatric patients is uncertain. We sought to determine the recurrence rate of symptomatic kidney stones in a cohort of children with incident symptomatic nephrolithiasis.

MATERIALS AND METHODS

We performed a retrospective cohort study of patients 3 to 18 years old without anatomical abnormalities or genetic causes of nephrolithiasis who presented with a first symptomatic kidney stone between 2008 and 2014. We determined recurrence rates of symptomatic nephrolithiasis, defined as a new kidney stone on ultrasound and/or computerized tomogram associated with pain and/or vomiting. We also estimated associations between completing 24-hour urinalysis and symptomatic kidney stone recurrence using Kaplan-Meier curves and multivariable Cox regression models.

RESULTS

A total of 285 children with a median age of 14.8 years (IQR 11.3-16.6) at nephrolithiasis diagnosis were followed for 492 person-years. A total of 86 symptomatic recurrent stones developed in 68 patients (24%) during the followup period. The probability of symptomatic stone recurrence was 50% at 3 years after the index kidney stone. Median time to stone recurrence was 3 years at the first recurrence and 5 years at the second. Adjusting for confounders including adherence to followup, completing a 24-hour urinalysis after a kidney stone episode was associated with a 60% decreased risk of recurrence (hazard ratio 0.40, 95% CI 0.18-0.91).

CONCLUSIONS

The risk of kidney stone recurrence is high during childhood, with approximately 50% of children presenting with symptomatic recurrence within 3 years of the first stone. The role and usefulness of analyzing 24-hour urine chemistries in decreasing kidney stone recurrence should be explored in future prospective studies.

Pediatric Cardiac Intensive Care Society 2014 Consensus Statement: Pharmacotherapies in Cardiac Critical Care Fluid Management

OBJECTIVE

In this Consensus Statement, we review the etiology and pathophysiology of fluid disturbances in critically ill children with cardiac disease. Clinical tools used to recognize pathologic fluid states are summarized, as are the mechanisms of action of many drugs aimed at optimal fluid management.

DATA SOURCES

The expertise of the authors and a review of the medical literature were used as data sources.

DATA SYNTHESIS

The authors synthesized the data in the literature in order to present clinical tools used to recognize pathologic fluid states. For each drug, the physiologic rationale, mechanism of action, and pharmacokinetics are synthesized, and the evidence in the literature to support the therapy is discussed.

CONCLUSIONS

Fluid management is challenging in critically ill pediatric cardiac patients. A myriad of causes may be contributory, including intrinsic myocardial dysfunction with its associated neuroendocrine response, renal dysfunction with oliguria, and systemic inflammation with resulting endothelial dysfunction. The development of fluid overload has been associated with adverse outcomes, including acute kidney injury, prolonged mechanical ventilation, increased vasoactive support, prolonged hospital length of stay, and mortality. An in-depth understanding of the many factors that influence volume status is necessary to guide optimal management.

Evaluation and medical management of kidney stones in children

PURPOSE

We review the current literature on the diagnostic evaluation and dietary and pharmacological management of children with nephrolithiasis.

MATERIALS AND METHODS

We searched MEDLINE(®), Embase(®) and the Cochrane Library from their inceptions to March 2014 for published articles in English on kidney stones and therapy in children 0 to 18 years old. Based on review of the titles and abstracts, 110 of the 1,014 articles (11%) were potentially relevant to the diagnostic evaluation and medical management of nephrolithiasis in children. We summarized this literature and drew on studies performed in adult populations to augment areas in which no studies of sufficient quality have been performed in children, and to highlight areas in need of research.

RESULTS

During the last 25 years the incidence of nephrolithiasis in children has increased by approximately 6% to 10% annually and is now 50 per 100,000 adolescents. Kidney stones that form during childhood have a similar composition to those that form in adulthood. Approximately 75% to 80% of stones are composed of predominantly calcium oxalate, 5% to 10% are predominantly calcium phosphate, 10% to 20% are struvite and 5% are pure uric acid. The recurrence rate of nephrolithiasis in patients with stones that form during childhood is poorly defined. Ultrasound should be used as the initial imaging study to evaluate children with suspected nephrolithiasis, with noncontrast computerized tomography reserved for those in whom ultrasound is nondiagnostic and the suspicion of nephrolithiasis remains high. Current treatment strategies for children with kidney stone disease are based largely on extrapolation of studies performed in adult stone formers and single institution cohort or case series studies of children. Tamsulosin likely increases the spontaneous passage of ureteral stones in children. Increased water intake and reduction of salt consumption should be recommended for all children with a history of kidney stones. Potassium citrate is a potentially effective medication for children with calcium oxalate stones and concomitant hypocitraturia, as well as children with uric acid stones. However, long-term compliance with therapy and the effect on decreasing stone recurrence in children are unknown. Based largely on efficacy in adult populations, thiazide diuretics should be considered in the treatment of children with calcium based stones and persistent hypercalciuria refractory to reductions in salt intake.

CONCLUSIONS

The incidence of kidney stone disease in children is increasing, yet few randomized clinical trials or high quality observational studies have assessed whether dietary or pharmacological interventions decrease the recurrence of kidney stones in children. Collaborative efforts and randomized clinical trials are needed to determine the efficacy and effectiveness of alternative treatments for children with nephrolithiasis, particularly those with calcium oxalate stones and concomitant hypercalciuria and hypocitraturia. Additional areas in need of study are the optimal length of time for a trial of stone passage in children, the cost-effectiveness of medical expulsive therapy vs analgesics alone, and the size and location of stones for which medical expulsive therapy is most effective.