Sodium Zirconium Cyclosilicate among Individuals with Hyperkalemia: A 12-Month Phase 3 Study

Prevention of Chronic Kidney Disease and Its Complications in Older Adults

In an era marked by a global demographic shift towards an aging society, there is a heightened prevalence of chronic kidney disease (CKD) among older adults. The burden of CKD spans from kidney-related complications to impacting psychological well-being, giving rise to depressive symptoms and caregiver burnout. This article delves into CKD prevention strategies within the context of aging, contributing to the discourse by exploring its multifaceted aspects. The prevention of CKD in the older adults necessitates a comprehensive approach. Primary prevention is centered on the modification of risk factors, acknowledging the intricate interplay of various comorbidities. Secondary prevention focuses on early CKD identification. Tertiary prevention aims to address factors contributing to CKD progression and complications, emphasizing the importance of timely interventions. This comprehensive strategy aims to enhance the quality of life for individuals affected by CKD, decelerating the deterioration of functional status. By addressing CKD at multiple levels, this approach seeks to effectively and compassionately care for the aging population.

Hyperkalemia treatment standard

Hyperkalemia is a common electrolyte disturbance in both inpatient and outpatient clinical practice. The severity and associated risk depends on the underlying cause and rate of potassium (K+) increase. Acute hyperkalemia requires immediate attention due to potentially life-threatening manifestations resulting from the rapid increase in plasma K+ concentration. Treatment is initially focused on stabilizing the cardiac membrane, followed by maneuvers to shift K+ into the cells, and ultimately initiating strategies to decrease total body K+ content. Chronic hyperkalemia develops over a more extended period of time and manifestations tend to be less severe. Nevertheless, the disorder is not benign since chronic hyperkalemia is associated with increased morbidity and mortality. The approach to patients with chronic hyperkalemia begins with a review of medications potentially responsible for the disorder, ensuring effective diuretic therapy and correcting metabolic acidosis if present. The practice of restricting foods high in K+ to manage hyperkalemia is being reassessed since the evidence supporting the effectiveness of this strategy is lacking. Rather, dietary restriction should be more nuanced, focusing on reducing the intake of nonplant sources of K+. Down-titration and/or discontinuation of renin-angiotensin-aldosterone inhibitors should be discouraged since these drugs improve outcomes in patients with heart failure and proteinuric kidney disease. In addition to other conservative measures, K+ binding drugs and sodium-glucose cotransporter 2 inhibitors can assist in maintaining the use of these drugs.

Consensus statement on the management of hyperkalaemia-An Asia-Pacific perspective

Hyperkalaemia is an electrolyte imbalance that impairs muscle function and myocardial excitability, and can potentially lead to fatal arrhythmias and sudden cardiac death. The prevalence of hyperkalaemia is estimated to be 6%-7% worldwide and 7%-10% in Asia. Hyperkalaemia frequently affects patients with chronic kidney disease, heart failure, and diabetes mellitus, particularly those receiving treatment with renin-angiotensin-aldosterone system (RAAS) inhibitors. Both hyperkalaemia and interruption of RAAS inhibitor therapy are associated with increased risks for cardiovascular events, hospitalisations, and death, highlighting a clinical dilemma in high-risk patients. Conventional potassium-binding resins are widely used for the treatment of hyperkalaemia; however, caveats such as the unpalatable taste and the risk of gastrointestinal side effects limit their chronic use. Recent evidence suggests that, with a rapid onset of action and improved gastrointestinal tolerability, novel oral potassium binders (e.g., patiromer and sodium zirconium cyclosilicate) are alternative treatment options for both acute and chronic hyperkalaemia. To optimise the care for patients with hyperkalaemia in the Asia-Pacific region, a multidisciplinary expert panel was convened to review published literature, share clinical experiences, and ultimately formulate 25 consensus statements, covering three clinical areas: (i) risk factors of hyperkalaemia and risk stratification in susceptible patients; (ii) prevention of hyperkalaemia for at-risk individuals; and (iii) correction of hyperkalaemia for at-risk individuals with cardiorenal disease. These statements were expected to serve as useful guidance in the management of hyperkalaemia for health care providers in the region.

Sodium Zirconium Cyclosilicate in CKD, Hyperkalemia, and Metabolic Acidosis: NEUTRALIZE Randomized Study

Key Points

Sodium zirconium cyclosilicate effectively lowers serum potassium and maintains normokalemia in patients with CKD with concomitant hyperkalemia and metabolic acidosis. Despite high screen failure and small sample size, a nominally significant increase in sHCO3– was seen for sodium zirconium cyclosilicate versus placebo. Further studies on the basis of an appropriate cohort size may help validate the trend observed in sHCO3– levels, supporting these clinically relevant findings.

Background

Metabolic acidosis and hyperkalemia are common in CKD. A potential dual effect of sodium zirconium cyclosilicate (SZC), a selective binder of potassium in the gastrointestinal tract, on serum potassium (sK+) and serum bicarbonate (sHCO3−) was evaluated in patients with hyperkalemia and metabolic acidosis associated with CKD.

Methods

In the NEUTRALIZE study (NCT04727528 ), non-dialysis patients with stage 3–5 CKD, hyperkalemia (sK+>5.0 to ≤5.9 mmol/L), and metabolic acidosis (sHCO3− 16–20 mmol/L) received open-label SZC 10 g three times daily for ≤48 hours. Patients achieving normokalemia (sK+ 3.5–5.0 mmol/L) were randomized 1:1 to SZC 10 g or placebo daily for 4 weeks. The primary end point was patients (%) maintaining normokalemia at the end of treatment (EOT) without rescue. Secondary end points included mean change in sHCO3− at EOT (day 29) and patients (%) with normokalemia with a ≥3-mmol/L increase in sHCO3− without rescue.

Results

Of 229 patients screened, 37 were randomized (SZC, n =17; placebo, n =20). High screen failure led to early study termination. At EOT, 88.2% (SZC) versus 20.0% (placebo) of patients maintained normokalemia (odds ratio, 56.2; P = 0.001). Low enrollment rendered secondary end point P values nominal. SZC treatment provided nominally significant increases in sHCO3– versus placebo from day 15 onward. Patients with normokalemia with a ≥3-mmol/L increase in sHCO3− without rescue were 35.3% (SZC) and 5.0% (placebo; P < 0.05). No new safety concerns were reported.

Conclusions

SZC effectively lowered sK+ and maintained normokalemia, with nominally significant increases in sHCO3– observed for SZC versus placebo.

Maintained renin-angiotensin-aldosterone system inhibitor therapy with sodium zirconium cyclosilicate following a hyperkalaemia episode: a multicountry cohort study

Background

This observational cohort study compared the likelihood of maintained (stabilized/up-titrated) renin-angiotensin-aldosterone system inhibitor (RAASi) therapy at 6 months following hyperkalaemia in patients with chronic kidney disease (CKD) and/or heart failure (HF) from the USA, Japan and Spain who received sodium zirconium cyclosilicate (SZC) for at least 120 days, relative to those with no prescription for a potassium (K+) binder.

Methods

Using health registers and hospital medical records, patients with CKD and/or HF receiving RAASi therapy who experienced a hyperkalaemia episode were identified. Propensity score (PS) matching (1:4) was applied to balance the SZC cohort to the no K+ binder cohort on baseline characteristics. Logistic regression analysis was performed to compare the odds of maintained RAASi therapy at 6 months in the SZC versus no K+ binder cohorts.

Results

The PS-matched SZC cohort included 565 (USA), 776 (Japan) and 56 (Spain) patients; the no K+ binder cohort included 2068, 2629 and 203 patients, respectively. At 6 months, 68.9% (USA), 79.9% (Japan) and 69.6% (Spain) in the SZC cohorts versus 53.1% (USA), 56.0% (Japan) and 48.3% (Spain) in the no K+ binder cohorts had maintained RAASi therapy. Meta-analysed across countries, the odds ratio of maintained RAASi therapy in the SZC cohort versus no K+ binder cohort was 2.56 (95% confidence interval 1.92-3.41; P < .0001).

Conclusions

In routine clinical practice across three countries, patients treated with SZC were substantially more likely to maintain guideline-concordant RAASi therapy at 6 months following hyperkalaemia relative to patients with no K+ binder treatment.

Cost-effectiveness of sodium zirconium cyclosilicate for advanced chronic kidney patients in Singapore

INTRODUCTION

Hyperkalaemia (HK) is prevalent among patients with chronic kidney disease (CKD) and chronic heart failure, especially if they are treated with renin-angiotensin-aldosterone system inhibitors (RAASi). This study evaluated the cost-effectiveness of a newly developed anti-HK therapy, sodium zirconium cyclosilicate (SZC), to the current standard of care for treating HK in advanced CKD patients from the Singapore health system perspective.

METHODS

We adapted a global microsimulation model to simulate individual patients' potassium level trajectories with baseline potassium ≥5.5 mmol/L, CKD progression, changes in treatment, and other fatal and non-fatal events. Effectiveness data was derived from ZS-004 and ZS-005 trials. Model parameters were localised using CKD patients' administrative and medical records at the Singapore General Hospital Department of Renal Medicine. We estimated the lifetime cost and quality-adjusted life years (QALYs) of each HK treatment, and the incremental cost-effectiveness ratio of SZC.

RESULTS

SZC demonstrated cost-effectiveness with an incremental cost-effectiveness ratsio of SGD 45 068 per QALY over a lifetime horizon, below the willingness-to-pay threshold of SGD 90 000 per QALY. Notably, SZC proved most cost-effective for patients with less severe CKD who were concurrently using RAASi. Sensitivity analyses confirmed the robustness of the findings, accounting for alternative parameter values and statistical uncertainty.

CONCLUSION

This study establishes the cost-effectiveness of SZC as a treatment for HK, highlighting its potential to mitigate the risk of hyperkalaemia and optimise RAASi therapy. These findings emphasise the value of integrating SZC into the Singapore health system for improved patient outcomes and resource allocation.

Evaluation of the introduction of novel potassium binders in routine care; the Stockholm CREAtinine measurements (SCREAM) project

BACKGROUND

The pharmacological management of hyperkalemia traditionally considered calcium or sodium polystyrene sulfonate and, since recently, the novel binders patiromer and sodium zirconium cyclosilicate. We evaluated their patterns of use, duration of treatment and relative effectiveness/safety in Swedish routine care.

METHODS

Observational study of adults initiating therapy with sodium polystyrene sulfonate or a novel binder (sodium zirconium cyclosilicate or patiromer) in Stockholm 2019-2021. We quantified treatment duration by repeated dispensations, compared mean achieved potassium concentration within 60 days, and potential adverse events between treatments.

RESULTS

A total of 1879 adults started treatment with sodium polystyrene sulfonate, and 147 with novel binders (n = 41 patiromer and n = 106 sodium zirconium cyclosilicate). Potassium at baseline for all treatments was 5.7 mmol/L. Sodium polystyrene sulfonate patients stayed on treatment a mean of 61 days (14% filled ≥3 consecutive prescriptions) compared to 109 days on treatment (49% filled ≥3 prescriptions) for novel binders. After 15 days of treatment, potassium similarly decreased to 4.6 (SD 0.6) and 4.8 (SD 0.6) mmol/L in the sodium polystyrene sulfonate and novel binder groups, respectively, and was maintained over the 60 days post-treatment. In multivariable regression, the odds ratio for novel binders (vs sodium polystyrene sulfonate) in reaching potassium ≤ 5.0 mmol/L after 15 days was 0.65 (95% CI 0.38-1.10) and after 60 days 0.89 (95% CI 0.45-1.76). Hypocalcemia, hypokalemia, and initiation of anti-diarrheal/constipation medications were the most-commonly detected adverse events. In multivariable analyses, the OR for these events did not differ between groups.

CONCLUSION

We observed similar short-term effectiveness and safety for all potassium binders. However, treatment duration was longer for novel binders than for sodium polystyrene sulfonate.

Safety and efficacy of sodium zirconium cyclosilicate for the management of acute and chronic hyperkalemia in children with chronic kidney disease 4-5 and on dialysis

BACKGROUND

Sodium zirconium cyclosilicate (SZC), an ion-exchange resin, is effective in the control of hyperkalemia in adults with chronic kidney disease (CKD); reports of use in children are limited. Prolonged therapy with SZC to relax dietary potassium restriction in CKD has not been examined.

METHODS

We conducted a retrospective chart review of patients 6 months to 18 years of age with CKD stage 4-5 or on dialysis (5D) administered SZC for sustained hyperkalemia (potassium ≥ 5.5 mEq/L, three consecutive values). Patients received SZC (0.5-10 g per dose; age-based) either short-term (< 30 days) or long-term (> 30 days).

RESULTS

Twenty patients with median age 10.8 (inter-quartile range 3.9, 13.4) years were treated with SZC. Short-term SZC, for 5 (3, 19) days, was associated with safe management of dialysis catheter insertions (n = 5) and access dysfunction (n = 4), and was useful during palliative care (n = 1). Serum potassium levels decreased from 6.7 (6.1, 6.9) to 4.4 (3.7, 5.2) mEq/L (P < 0.001). Long-term SZC for 5.3 (4.2, 10.1) months achieved decline in serum potassium from 6.1 (5.8, 6.4) to 4.8 (4.2, 5.4) mEq/L (P < 0.001). SZC use was associated with liberalization of diet (n = 6) and was useful in patients with poor adherence to dietary restriction (n = 3). Adverse events or edema were not observed; serum sodium and blood pressure remained stable.

CONCLUSIONS

SZC was safe and effective for the management of acute and chronic hyperkalemia in children with CKD4-5/5D. Its use was associated with relaxation of dietary potassium restriction. Studies to examine its routine use to improve diet and nutritional status in children with CKD are required.

Population Pharmacodynamic Dose-Response Analysis of Serum Potassium Following Dosing with Sodium Zirconium Cyclosilicate

BACKGROUND

Sodium zirconium cyclosilicate (SZC) is an approved oral treatment for hyperkalemia that selectively binds potassium (K+) in the gastrointestinal tract and removes K+ from the body through increased fecal excretion. Here, we describe the population pharmacodynamic (PopPD) response of serum K+ concentration in patients with hyperkalemia who are treated with SZC, estimate the impact of patients' intrinsic and extrinsic factors, and compare predicted serum K+ responses between 5 g alternate daily (QOD) and 2.5 g once daily (QD) maintenance doses.

METHODS

PopPD analysis was based on pooled data from seven phase II and III clinical trials for SZC. A semi-mechanistic longitudinal mixed-effects (base) model was used to characterize serum K+ concentration after SZC dosing. Indirect-response, virtual pharmacokinetics-pharmacodynamics (PK-PD) modeling was used to mimic the drug exposure compartment. Full covariate modeling was used to assess covariate impact on the half-maximal effective concentration of drug (EC50), placebo response, and Kout. Models were evaluated using goodness-of-fit plots, relative standard errors, and visual predictive checks, and data were stratified to optimize model performance across subgroups. Covariate effects were evaluated based on the magnitude of change in serum K+ between baseline and end of correction phase dosing (48 h, SZC 10 g three times a day) and maintenance phase dosing (28 days, SZC 10 g QD) using a reference subject.

RESULTS

The analysis data set included 2369 patients and 25,764 serum K+ observations. The mean (standard deviation) patient age was 66.0 (12) years, 61% were male, 68% were White, 34% had congestive heart failure, and 62% had diabetes. Mean (standard deviation) serum K+ at baseline was 5.49 (0.43) mmol/L. Both the base and full covariance models adequately described observed data. In the final model, there was a sigmoid exposure response on Kin, with EC50 of 32.8 g and a Hill coefficient of 1.36. The predicted placebo-adjusted dose-responses of serum K+ change appeared nearly linear in the correction and maintenance phases. No clinically meaningful difference in placebo-adjusted serum K+ change from baseline at 28 days was observed between maintenance regimens of SZC 5 g QOD and 2.5 g QD. A greater SZC treatment response was associated with high serum K+ at baseline, advanced age, lower body weight, lower estimated glomerular filtration rate, and Black/African American and Asian race, compared with the reference patient. The impact of heart failure status and diabetes status was only minor.

CONCLUSIONS

The PopPD model of SZC adequately described changes in serum K+ concentration during correction and maintenance phase dosing. A greater treatment response was associated with various covariates, but the impact of each was modest. Overall, these findings suggest that no adjustment in SZC dose is needed for any of the covariates evaluated.

Recommendations for the management of hyperkalemia in patients receiving renin-angiotensin-aldosterone system inhibitors

Hyperkalemia is common in clinical practice and can be caused by medications used to treat cardiovascular diseases, particularly renin-angiotensin-aldosterone system inhibitors (RAASis). This narrative review discusses the epidemiology, etiology, and consequences of hyperkalemia, and recommends strategies for the prevention and management of hyperkalemia, mainly focusing on guideline recommendations, while recognizing the gaps or differences between the guidelines. Available evidence emphasizes the importance of healthcare professionals (HCPs) taking a proactive approach to hyperkalemia management by prioritizing patient identification and acknowledging that hyperkalemia is often a long-term condition requiring ongoing treatment. Given the risk of hyperkalemia during RAASi treatment, it is advisable to monitor serum potassium levels prior to initiating these treatments, and then regularly throughout treatment. If RAASi therapy is indicated in patients with cardiorenal disease, HCPs should first treat chronic hyperkalemia before reducing the dose or discontinuing RAASis, as reduction or interruption of RAASi treatment can increase the risk of adverse cardiovascular and renal outcomes or death. Moreover, management of hyperkalemia should involve the use of newer potassium binders, such as sodium zirconium cyclosilicate or patiromer, as these agents can effectively enable optimal RAASi treatment. Finally, patients should receive education regarding hyperkalemia, the risks of discontinuing their current treatments, and need to avoid excessive dietary potassium intake.

Randomised, blinded, cross-over evaluation of the palatability of and preference for different potassium binders in participants with chronic hyperkalaemia in the USA, Canada and Europe: the APPETIZE study

OBJECTIVES

Traditional potassium (K+) binders for treating hyperkalaemia are unpalatable and poorly tolerated. Newer K+ binders are reportedly better tolerated; however, no published data describe their palatability, a determinant of long-term adherence. This study evaluated the palatability of and preference for three K+ binders: sodium and calcium polystyrene sulfonate (S/CPS), sodium zirconium cyclosilicate (SZC) and calcium patiromer sorbitex (patiromer).

DESIGN

Phase 4, randomised, participant-blinded, cross-over study. Participants were randomised to one of six taste sequences and, using a 'sip and spit' approach, tasted each K+ binder before completing a survey.

SETTING

17 centres across the USA, Canada and European Union.

PARTICIPANTS

144 participants with chronic kidney disease, hyperkalaemia and no recent use of K+ binders.

MAIN OUTCOME MEASURES

For the primary (USA) and key secondary (Canada and European Union) endpoints, participants rated palatability attributes (taste, texture, smell and mouthfeel) and willingness to take each K+ binder on a scale of 0-10 (rational evaluation). Feelings about each attribute, and the idea of taking the product once daily, were evaluated using a non-verbal, visual measure of emotional response. Finally, participants ranked the K+ binders according to palatability.

RESULTS

In each region, SZC and patiromer outperformed S/CPS on overall palatability (a composite of taste, texture, smell and mouthfeel), based on rational evaluation and emotional response. Taking the product once daily was more appealing for SZC and patiromer, creating greater receptivity than the idea of taking S/CPS. The emotional response to mouthfeel had the strongest influence on feelings about taking each product. In each region, a numerically greater proportion of participants ranked SZC as the most preferred K+ binder versus patiromer or S/CPS.

CONCLUSIONS

Preference for more palatable K+ binders such as SZC and patiromer may provide an opportunity to improve adherence to long-term treatment of hyperkalaemia.

TRIAL REGISTRATION NUMBER

NCT04566653.

Sodium zirconium cyclosilicate reconciles management of hyperkalemia and continuity of renin-angiotensin-aldosterone system inhibitors: a retrospective observational study

BACKGROUND

Sodium zirconium cyclosilicate, a non-absorbed non-polymer zirconium silicate, is a new potassium binder for hyperkalemia. A previous report showed that administering sodium zirconium cyclosilicate to patients with hyperkalemia allows a higher continuation rate of renin-angiotensin-aldosterone system inhibitors. However, no studies have compared sodium zirconium cyclosilicate with existing potassium binders for renin-angiotensin-aldosterone system inhibitor continuity. The purpose of this study was to evaluate the effect of sodium zirconium cyclosilicate on angiotensin-converting enzyme inhibitor /angiotensin receptor blocker continuation in patients with hyperkalemia compared to that of calcium polystyrene sulfonate.

METHODS

Patients on angiotensin-converting enzyme inhibitors/angiotensin receptor blockers who were newly prescribed sodium zirconium cyclosilicate or calcium polystyrene sulfonate to treat hyperkalemia at a tertiary referral hospital between August 2020 and April 2022 were enrolled in this single-center, retrospective observational study. The primary outcome measure was angiotensin-converting enzyme inhibitor/angiotensin receptor blocker prescription three months after initiating potassium binders.

RESULTS

In total, 174 patients on angiotensin-converting enzyme inhibitors/angiotensin receptor blockers who were newly administered sodium zirconium cyclosilicate (n = 62) or calcium polystyrene sulfonate (n = 112) were analyzed. The prescription rate of angiotensin-converting enzyme inhibitors /angiotensin receptor blockers at 3 months was significantly higher in the sodium zirconium cyclosilicate group than in the calcium polystyrene sulfonate group (89 vs. 72%). Multivariate logistic regression models showed that sodium zirconium cyclosilicate was independently associated with the primary outcome (odds ratio 2.66, 95% confidence interval 1.05-7.43). The propensity score-matched comparison also showed a significant association between sodium zirconium cyclosilicate and the primary outcome.

CONCLUSIONS

Our study suggests that administering sodium zirconium cyclosilicate to patients with hyperkalemia allows for a higher continuation rate of angiotensin-converting enzyme inhibitors/angiotensin receptor blockers than calcium polystyrene sulfonate. These findings suggest that sodium zirconium cyclosilicate has potential benefits for patients with chronic kidney disease receiving renin-angiotensin-aldosterone system inhibitors.

Cost-effectiveness analysis of sodium zirconium cyclosilicate for hyperkalemia among patients with chronic kidney disease or heart failure in Kuwait

INTRODUCTION

Our model was conducted from Kuwaiti payer's perspective to provide evidence on the cost-effectiveness of Sodium zirconium cyclosilicate (SZC) versus patiromer to correct and maintain serum potassium (K+) in combination with renin-angiotensin-aldosterone system inhibitors (RAASis) with different dose titration in patients with chronic kidney disease/heart failure (CKD/HF) with/without renal replacement therapy (RRT).

METHODOLOGY

The model was developed as a patient-level, fixed-time increment stochastic simulation to simulate the complexity of disease, including multiple coexisting and competing conditional risks. This model was established to compare SZC versus patiromer as a treatment for hyperkalemia (HK) among adult populations with underlying conditions of advanced CKD stages 3a-5 or HF to correct and maintain serum K + over a lifetime horizon. The clinical outcomes of SZC and patiromer were demonstrated through arm-specific K + trajectories extracted from the HARMONIZE trial and OPAL-HK trial, respectively. The utility data was captured from different studies. Direct medical cost was captured from local data from Kuwaiti hospitals. Sensitivity analyses were conducted to assess the uncertainty in the model.

RESULTS

Within different scenarios of CKD/HF, SZC was a cost-saving option, with/without RRT, whether one-off administration or repeated administration, except for one-off treatment administration among the HF cohort, which generated an incremental cost effectiveness ratio of KWD 331/quality adjusted life year (QALY). The incremental QALY of SZC ranged from 0.007 to 0.202. In addition, the savings observed with SZC fall within a range of KWD -60 to KWD -1,235 at serum K+ ≥ 5.1 mmol/L.

CONCLUSION

The evidence generated by our model recommends the inclusion of SZC as a treatment option to correct HK and maintain normal serum K + level for CKD/HF patients within the Kuwaiti healthcare system. The costs saved from reducing frequent HK episodes, RAASis discontinuation/down titration, major cardiovascular events, and hospitalization offset the drug acquisition cost of SZC.

Hyperkalemia: Pharmacotherapies and Clinical Considerations

Hyperkalemia has been defined as a condition where a serum potassium level is >5.5 mmol/l. It is associated with fatal dysrhythmias and muscular dysfunction. Certain medical conditions, such as chronic kidney disease (CKD), diabetes mellitus, and others, can lead to hyperkalemia. Many of the signs of hyperkalemia are nonspecific. A history and physical examination can be beneficial in the diagnosis of the condition. In this regard, certain characteristic electrocardiogram findings are associated with hyperkalemia along with laboratory potassium levels. In acute and potentially lethal conditions, hyperkalemia treatments include glucose and insulin, bicarbonate, calcium gluconate, beta-2 agonists, hyperventilation, and dialysis. There are several drugs, both old and new, that can additionally aid in the reduction of serum potassium levels. The present investigation evaluated some of these different drugs, including sodium polystyrene sulfonate (SPS), sodium zirconium cyclosilicate (SZC), and patiromer. These drugs each have increased selectivity for potassium and work primarily in the gastrointestinal (GI) tract. Each of these medications has unique benefits and contraindications. Clinicians must be aware of these medications when managing patients with hyperkalemia.

Cost-effectiveness analysis of sodium zirconium cyclosilicate for treating hyperkalemia among Chinese patients

Objectives

Hyperkalemia most commonly develops in chronic kidney disease (CKD) or heart failure (HF) patients. Sodium zirconium cyclosilicate (SZC) is a new selective potassium (K+) binder for treating hyperkalemia. The aim of this study was to evaluate the cost-effectiveness of SZC vs. usual care for the treatment of hyperkalemia among CKD patients or HF patients in China.

Methods

Individual patient microsimulation models were constructed to simulate a CKD cohort until the initiation of renal replacement therapy (RRT) and a HF cohort across the lifetime horizon. K+ levels were based on two phase 3 clinical trials. Health state utility and event incidence rates were retrieved from literature. Drug costs and healthcare utilization costs were obtained from negotiated price, literature, and expert interviews. Costs and quality-adjusted life-years (QALYs) were both discounted at 5%. The main outcomes were overall costs, QALYs, and incremental cost-effectiveness ratio (ICER). The willingness-to-pay (WTP) threshold in China is CNY 80,976-242,928/QALY, which is one to three times the gross domestic product per capita. Sensitivity analyses were performed to characterize the models' uncertainty.

Results

In the HF cohort, the base case results revealed that SZC was associated with 2.86 QALYs and the total cost was CNY 92671.58; usual care was associated with 1.81 QALYs and CNY 54101.26. In the CKD cohort, SZC was associated with 3.23 QALYs and CNY 121416.82 total cost; usual care was associated with 2.91 QALYs and CNY 111464.57. SZC resulted in an ICER of CNY 36735.87/QALY for the HF cohort and CNY 31181.55/QALY for the CKD cohort, respectively. The one-way and probability sensitivity analyses found that the results were robust.

Conclusion

SZC is a cost-effective treatment compared to usual care in HF and CKD patients. SZC is an important novel treatment option for managing patients with hyperkalemia in China.

Novel Therapies in Diabetic Kidney Disease and Risk of Hyperkalemia: A Review of the Evidence From Clinical Trials

Concerns about hyperkalemia may result in the underuse of established and novel therapies that improve kidney and/or cardiovascular (CV) outcomes in patients with type 2 diabetes mellitus (T2DM) and chronic kidney disease (CKD). Hyperkalemia-related issues are of particular relevance in patients with CKD, who are commonly receiving other hyperkalemia-inducing agents such as renin-angiotensin-aldosterone system inhibitors and nonsteroidal mineralocorticoid receptor antagonists. In contrast, sodium/glucose transporter 2 (SGLT2) inhibitors mitigate the risk of serious hyperkalemia in clinical trials. We aim to review recent evidence surrounding the risk of hyperkalemia in patients with T2DM and CKD treated with established and novel therapies for diabetic kidney disease, focusing on SGLT2 inhibitors and nonsteroidal mineralocorticoid receptor antagonists. We conclude that SGLT2 inhibitors can be used safely in patients with T2DM at high CV risk with CKD without increasing the risk of hyperkalemia. Routine potassium monitoring is generally required when finerenone is used as a kidney- and CV-protective agent in patients with T2DM. Based on existing data, when added to the standard of care, combining SGLT2 inhibitors with finerenone is safe and has the potential to exert additional cardiorenal benefits in patients with diabetic kidney disease. The use of potassium binders should be considered to enable optimal doses of guideline-based therapies for patients with diabetic kidney disease to maximize the kidney and CV benefits.

Financial Implication of Sodium Zirconium Cyclosilicate Therapy in Patients with Systolic Heart Failure and Hyperkalemia

Sodium zirconium cyclosilicate (SZC), a newly-introduced potassium binder, can be used to manage hyperkalemia especially in patients with chronic kidney disease and in those on medical therapy which may raise serum potassium levels. The medication may incur additional costs but may in turn have a significant benefit in the effect of maintaining guideline-directed medical therapy for heart failure. We aimed to investigate the financial impact of SZC therapy in patients with systolic heart failure.Patients with systolic heart failure who received SZC for hyperkalemia between July 2020 and March 2023 were included. In-hospital medical costs were compared between the patients who discontinued SZC and those who continued SZC. For the continue group, the cost of SZC was added. All patients were followed for 2 years or until May 2023.A total of 36 patients (median age 81 years, 56% male, median left ventricular ejection fraction 43%) were included. Total medical costs were significantly lower in the continue group (n = 12) compared to the discontinue group (n = 24) (3.1 [3.1, 6.2] versus 12.1 [3.8, 48.6] × 104 JPY per month, P = 0.039). In the continue group, serum potassium levels were decreased, renin-angiotensin-aldosterone system inhibitor doses were up-titrated, and the left ventricular ejection fraction was increased, whereas these parameters remained unchanged or worsened in the discontinue group.SZC may have the potential to assist in the up-titration of potassium-sparing heart failure-specific medications, prevent readmissions, and minimize medical costs, by preventing recurrent hyperkalemia in patients with systolic heart failure.

Clinical outcomes by serum potassium levels for patients hospitalized for heart failure: Secondary analysis of data from the China National Heart Failure Registry

BACKGROUND

Dyskalemia is a mortality risk factor in patients with heart failure (HF).

HYPOTHESIS

We described the prevalence of dyskalemia, and clinical outcomes by serum potassium (sK) levels, in Chinese patients hospitalized for HF.

METHODS

In this secondary analysis of the prospective China National Heart Failure Registry, adult patients hospitalized between January 1, 2013 and June 30, 2015 who had at least one baseline sK measurement were followed for up to 3 years after discharge. The use of renin-angiotensin-aldosterone system inhibitors at baseline and clinical outcomes during follow-up were compared among sK groups.

RESULTS

Among 6950 patients, 5529 (79.6%) had normokalemia (sK >3.5-5.0 mmol/L), 1113 (16.0%) had hypokalemia (sK 0-3.5 mmol/L), and 308 (4.4%) had hyperkalemia (sK >5.0 mmol/L). Baseline characteristics that were most common in patients with hyperkalemia than those with hypo- and normokalemia included older age, HF with reduced ejection fraction, New York Heart Association Class III/IV status, hypertension, and chronic kidney disease. Use of angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) differed across sK groups (p = .0001); reported in 64.1%, 63.4%, and 54.5% of patients with hypo-, normo-, and hyperkalemia, respectively. Overall, 26.6%, 28.6%, and 36.0% of patients with hypo-, normo-, and hyperkalemia had rehospitalization for worsened HF, or cardiovascular mortality; p = .0057 for between-group comparison.

CONCLUSIONS

Patients with hyperkalemia received ACEIs or ARBs for HF treatment at baseline less frequently than those with hypo- or normokalemia, and had worse prognoses. This warrants further investigation into effective hyperkalemia management in HF.

Practical patient care appraisals with use of new potassium binders in heart failure and chronic kidney diseases

Hyperkalaemia is a life-threatening condition leading to significant morbidity and mortality. It is common in heart failure and in chronic kidney disease (CKD) patients due to the diseases themselves, which often coexist, the high co-presence of diabetes, the fluctuations in renal function, and the use of some drugs [i.e. renin-angiotensin-aldosterone system (RAAS) inhibitors]. Hyperkalaemia limits their administration or uptitration, thus impacting on mortality. New K + binders, namely patiromer and sodium zirconium cyclosilicate (ZS-9), are an intriguing option to manage hyperkalaemia in heart failure and/or CKD patients, both to reduce its fatal effects and to let clinicians uptitrate RAAS inhibition. Even if their real impact on strong outcomes is still to be determined, we hereby provide a practical approach to favour their use in routine clinical practice in order to gain the correct confidence and provide an additive tool to heart failure and CKD patients' wellbeing. New trials are welcome to fill the gap in knowledge.

Management of Hyperkalemia in Patients with Chronic Kidney Disease Using Renin Angiotensin Aldosterone System Inhibitors

PURPOSE OF REVIEW

Use of renin-angiotensin-aldosterone system (RAAS) inhibiting medications is critical in the prevention of cardiovascular disease and kidney function decline in patients with chronic kidney disease (CKD); however, these agents can lead to hyperkalemia, an electrolyte disorder associated with risk of arrythmia, conduction disorders, and increased overall mortality. Discontinuation, or reduction of dose, of RAAS inhibitor therapy in hyperkalemic patients with CKD can lead to loss of kidney and cardiovascular protection afforded by these medications. Given the high prevalence of hyperkalemia among patients with CKD utilizing RAAS inhibitors, clear management principles are critical to minimize risk and maximize benefit when facing this clinical dilemma.

RECENT FINDINGS

Strategies to mitigate hyperkalemia that do not interfere with optimal RAAS inhibitor therapy should be prioritized when managing potassium elevation in patients with CKD. These strategies include discontinuing non-RAAS inhibitor medications known to cause hyperkalemia, correction of metabolic acidosis, and maximization of medication therapies that lower serum potassium, including diuretics and sodium-glucose cotransporter-2 (SGLT-2) inhibitors. Initiation of potassium exchange resins should also be considered to allow for sustained RAAS inhibitor utilization. An approach which employs multiple strategies concurrently is important to mitigate hyperkalemia and maintain long-term use of RAAS-inhibitors. Persistence of RAAS inhibitor use in patients with CKD is important to slow kidney function decline, delay onset of dialysis or the need for kidney transplant, and prevent adverse cardiovascular outcomes. When hyperkalemia develops among patients with CKD utilizing a RAAS inhibitor, a deliberate effort to reduce serum potassium levels using an approach that allows for continuation of maximally dosed RAAS inhibitor therapy is important. Patient education and engagement in the potassium management process is important for sustained success.

Consensus document on the management of hyperkalemia

Hyperkalaemia is a common electrolyte imbalance with potentially serious short-, medium- and long-term consequences on morbidity and mortality rates and the use of national health service resources. The fact that different medical specialities can manage hyperkalaemia makes it important to have a unified approach, and the recent availability of new specific drug treatments means that the approach needs to be updated. This consensus document from the scientific societies most directly involved in the management of hyperkalaemia (Sociedad Española de Cardiología [Spanish Society of Cardiology], Sociedad Española de Endocrinología y Nutrición [Spanish Society of Endocrinology and Nutrition], Sociedad Española de Medicina Interna [Spanish Society of Internal Medicine], Sociedad Española de Medicina de Urgencias y Emergencias [Spanish Society of Accident and Emergency Medicine] and Sociedad Española de Nefrología [Spanish Society of Nephrology]) first of all reviews basic aspects of potassium balance and blood potassium. Then it goes on to focus on the concept, epidemiology, pathophysiology and diagnostic and therapeutic approaches to hyperkalaemia. The available evidence and the main published studies have been reviewed with the aim of providing a useful tool in the multidisciplinary approach to patients with hyperkalaemia.

Impact of Sodium Zirconium Cyclosilicate Plus Renin-Angiotensin-Aldosterone System Inhibitor Therapy on Short-Term Medical Costs in Hyperkalemia: OPTIMIZE II Real-World Study

INTRODUCTION

Patients receiving cardiorenal-protective renin-angiotensin-aldosterone system inhibitors (RAASis) are at increased risk of developing hyperkalemia, which is associated with increased medical costs. The aim of this study was to evaluate the impact of adding sodium zirconium cyclosilicate (SZC) therapy on 3-month medical costs in patients who experienced hyperkalemia while receiving RAASi therapy.

METHODS

The retrospective OPTIMIZE II study used medical and pharmacy claims data from IQVIA PharMetrics® Plus. Patients aged ≥ 18 years who received SZC (≥ 60 day supply over 3 months' follow-up) and continued RAASi between July 2019 and December 2021 (Continue RAASi + SZC cohort) were 1:1 exact and propensity score matched with patients who discontinued RAASi after hyperkalemia diagnosis and did not receive SZC (Discontinue RAASi + no SZC cohort). The primary outcome was hyperkalemia-related medical costs to payers over 3 months; all-cause medical and pharmacy costs were also analyzed.

RESULTS

In the Continue RAASi + SZC (n = 467) versus Discontinue RAASi + no SZC (n = 467) cohort, there were significant reductions in mean per-patient hyperkalemia-related medical costs (reduction of $2216.07; p = 0.01) and all-cause medical costs (reduction of $6102.43; p < 0.001); mean hyperkalemia-related inpatient medical costs and all-cause inpatient and emergency department medical costs were significantly reduced. The reduction in all-cause medical cost in the Continue RAASi + SZC cohort offset an increase in the mean per-patient all-cause pharmacy cost (increase of $3117.71; p < 0.001).

CONCLUSION

RAASi therapy has well-established cardiorenal benefits. In OPTIMIZE II, management of RAASi-induced hyperkalemia with SZC was associated with lower hyperkalemia-related and all-cause medical costs than RAASi discontinuation without SZC, demonstrating medical cost savings with maintaining RAASi therapy with SZC.

Management of Hypertension in Diabetic Kidney Disease

Hypertension is a critical component of cardiovascular disease progression in patients with chronic kidney disease, and specifically diabetic kidney disease (DKD). Causation versus correlation remains up for debate, but what has been confirmed is the delay of DKD progression when hypertension is controlled or moved to guideline drive ranges. Many medications have been studied and used in real world experience for best outcomes, and we discuss below the proven winners thus far making up the renin angiotensin aldosterone system. As well, we discuss guideline changing medications including sodium-glucose cotransporter 2 inhibitors and newer generation mineralocorticoid receptor antagonists. With the growing prevalence of diabetes and DKD in the population, newer agents are emerging in multiple drug class and will be highlighted below. Clinicians continue to search for the optimal care plans for this challenging patient population.

Medical Costs in Patients with Hyperkalemia on Long-Term Sodium Zirconium Cyclosilicate Therapy: The RECOGNIZE II Study

Purpose

Hyperkalemia, defined as abnormally high serum potassium levels of ≥5.1 mmol/L, is associated with increased medical costs. This real-world study evaluated the impact of long-term sodium zirconium cyclosilicate (SZC) therapy on medical costs in patients with hyperkalemia.

Patients and Methods

This retrospective, comparative study used claims data from IQVIA PharMetrics® Plus. Patients aged ≥18 years with hyperkalemia who had outpatient SZC fills (>3-month supply over 6 months) between July 2019 and December 2021 and continuous insurance coverage 6 months before and 6 months after the first SZC fill were included. These patients (SZC cohort) were 1:1 exact- and propensity score-matched on baseline variables with patients with hyperkalemia who did not receive SZC (non-SZC cohort). The primary endpoint was hyperkalemia-related medical costs to payers over 6 months.

Results

Each cohort included 661 matched patients. Mean per-patient hyperkalemia-related medical costs were reduced by 49.5% ($3728.47) for the SZC versus non-SZC cohort ($3798.04 vs $7526.51; P<0.001), whereas mean all-cause medical costs were reduced by 21.0% ($5492.20; $20,722.23 vs $26,214.43; P<0.01). A 39.8% ($3621.03) increase in all-cause pharmacy costs ($12,727.20 vs $9106.17; P<0.01) was offset by the medical cost savings.

Conclusion

This study demonstrated that long-term (>3 months) outpatient treatment with SZC was associated with medical cost savings compared with no SZC therapy.

Constipation as a Drug-Related Adverse Effect in Patients with Hyperkalemia: Sodium Zirconium Cyclosilicate versus Conventional Potassium Binders

(1) Background: Constipation is one of the most serious adverse effects of potassium-lowering agents and decreases patients' quality of life. Sodium zirconium cyclosilicate (SZC) is a recently innovated potassium binder intended for patients with hyperkalemia. The impact of SZC on the worsening of constipation, as compared with conventional potassium binders, remains unknown. (2) Methods: Patients with hyperkalemia who continued SZC for over 3 months between July 2020 and May 2022 were included in this retrospective study. Patients who received other conventional potassium binders during the same period were included as a control group. Trends in the doses of anti-constipation agents during the 3-month therapeutic period were compared between the two groups as a surrogate for worsening constipation. (3) Results: A total of 50 patients (median age 74 years, 31 male) were included, consisting of 22 patients with SZC and 28 patients with other conventional potassium binders. All patients had hyperkalemia and chronic kidney disease at baseline. During the 3-month therapeutic period, serum potassium levels decreased significantly in both groups (p < 0.05 for both). The number of anti-constipation remained unchanged in the SZC group but tended to increase in the control group (p = 0.56 and p = 0.090, respectively). The total dose change in all anti-constipations was significantly lower in the SZC group than in the control group (p = 0.037). (4) Conclusions: Conventional potassium binders have a tendency to worsen constipation, whereas SZC may have the potential to improve hyperkalemia without worsening constipation. SZC may be recommended, particularly in elderly patients with ongoing or high-risk constipation.

A Real-World Experience of Hyperkalemia Management Using Sodium Zirconium Cyclosilicate in Chronic Hemodialysis: A Multicenter Clinical Audit

INTRODUCTION

 Hyperkalemia, a common condition among hemodialysis (HD) patients, is associated with adverse health outcomes. Evidence of the safety and efficacy of a potassium-binder, sodium zirconium cyclosilicate (SZC), has been limited among Asian (HD) patients beyond phase 3 trials. This article demonstrates real-world evidence of SZC usage in an Asian cohort of HD patients.

METHODS

 A retrospective clinical audit was conducted among 293 patients who received maintenance HD at community-based dialysis centers in Singapore. Patients received SZC for either management of hyperkalemia or hyperkalemia prevention during anticipated disruption to dialysis, such as during traveling. Among patients treated for hyperkalemia (N = 147), serum potassium (K+) prior to SZC initiation and at the endpoint was compared using a paired Student's t-test. Changes in K+ from baseline to endpoint were compared across various categories within each demographic and health-related variables using either Student's t-test or one-way ANOVA. Patients who experienced adverse events after SZC initiation or were deceased during the audit were reviewed to provide a descriptive account.

RESULTS

 Among patients who received SZC for hyperkalemia treatment, SZC use was associated with a significant reduction of 0.812 mmol/L in serum potassium. Patients with ethnicities other than Chinese, Malay, or Indian had a nominal reduction in K+ of 0.7 mmol/L and this can be accounted for the small sample size of this sub-group. The three main ethnicities which represented more than 95% of the sample showed a significant reduction in K+ levels (all three p<0.001). This is consistent with other studies with SZC which showed efficacy across various ethnicities. Patients who received SZC for hyperkalemia treatment or prevention had a significant lowering of mortality rate. This mortality reduction may have inherent biases and confounders, due to the retrospective clinical audit study design.  Conclusions: Overall, SZC was safe and effective among the audited patients. The efficacy in the real-world setting was similar to previous trials. The novel use of SZC to manage serum potassium when HD sessions are missed, such as during traveling, warrants further investigation due to potentially significant life-saving implications.

Hyperkalemia in chronic kidney disease: a focus on potassium lowering pharmacotherapy

INTRODUCTION

Hyperkalemia is one of the most common electrolyte disorders in chronic kidney disease (CKD) and is associated with serious adverse outcomes. Hyperkalemia risk is even greater when CKD patients also have additional predisposing conditions such as diabetes or heart failure. Renin-angiotensin-aldosterone-system blockers are first-line treatments for cardio- and nephroprotection, but their use is often limited due to K+ elevation, resulting in high rates of discontinuation.

AREAS COVERED

This article provides an overview of factors interfering with K+ homeostasis and discusses recent data on newer therapeutic agents used for the treatment of hyperkalemia. A detailed literature search was performed in two major databases (PubMed/MEDLINE and Scopus) up to April 2023.

EXPERT OPINION

Major clinical trials have tested new and promising kidney protective therapies such as sodium/glucose-cotransporter-2 inhibitors and mineralocorticoid-receptor-antagonists, with promising results. Until recently, the only treatment option for hyperkalemia was the cation-exchanging resin sodium-polystyrene-sulfonate. However, despite its common use, the efficacy and safety data of this drug in the long-term management of hyperkalemia are scarce. During the last decade, two novel orally administered K+-exchanging compounds (patiromer and sodium-zirconium-cyclosilicate) have been approved for the treatment of adults with hyperkalemia, as they both effectively reduce elevated serum K+ and maintain chronically K+ balance within the normal range with an excellent tolerability and no serious adverse events.

Potassium homeostasis - Physiology and pharmacology in a clinical context

Membrane voltage controls the function of excitable cells and is mainly a consequence of the ratio between the extra- and intracellular potassium concentration. Potassium homeostasis is safeguarded by balancing the extra-/intracellular distribution and systemic elimination of potassium to the dietary potassium intake. These processes adjust the plasma potassium concentration between 3.5 and 4.5 mmol/L. Several genetic and acquired diseases but also pharmacological interventions cause dyskalemias that are associated with increased morbidity and mortality. The thresholds at which serum K+ not only associates but also causes increased mortality are hotly debated. We discuss physiologic, pathophysiologic, and pharmacologic aspects of potassium regulation and provide informative case vignettes. Our aim is to help clinicians, epidemiologists, and pharmacologists to understand the complexity of the potassium homeostasis in health and disease and to initiate appropriate treatment strategies in dyskalemic patients.

Sodium polystyrene is unsafe and should not be prescribed for the treatment of hyperkalaemia: primum non nocere!

'Old-generation' potassium (K) binders [i.e. sodium (SPS) and calcium polystyrene sulfonate] are widely used, but with substantial heterogeneity across countries to treat hyperkalaemia (HK). However, there are no randomized data to support their chronic use to manage HK, nor have they been shown to have a renin-angiotensin-aldosterone system inhibitor (RAASi)-enabling effect. These compounds have poor tolerability and an unpredictable onset of action and magnitude of K lowering. Furthermore, SPS may induce fluid overload, owing to the fact that it exchanges K for sodium. Its use has also been associated with colonic necrosis, as emphasized by a black box warning from the US Food and Drug Administration. In contrast, two new K binders, patiromer and sodium zirconium cyclosilicate, have been shown to be safe and well tolerated for chronic management of HK, thereby enabling RAASi optimization, as acknowledged by the latest international cardiorenal guidelines. In view of the lack of reliable evidence regarding the efficacy and safety of the old-generation K binders compared with the placebo-controlled randomized and real-word evidence demonstrating the safety, efficacy and RAASi-enabling effect of the new K binders, clinicians should now use these new K binders to treat HK (primum non nocere!).

Pharmacological strategies to manage hyperkalaemia: out with the old, in with the new? Not so fast…

Since the 1950s, sodium polystyrene sulphonate (SPS) has been the dominant cation exchange agent prescribed for hyperkalaemia. Clinicians have had plenty of time to learn of SPS's advantages and limitations. The demands of drug regulatory agencies regarding the incorporation of medications into the market were not so stringent then as they are today, and the efficacy and safety of SPS have been questioned. In recent years, two novel cation exchangers, patiromer and sodium zirconium cyclosilicate, have received (or are in the process of receiving) regulatory approval in multiple jurisdictions globally, after scrutiny of carefully conducted trials regarding their short-term and mid-term efficacy. In this debate, we defend the view that all three agents are likely to have similar efficacy. Harms are much better understood for SPS than for newer agents, but currently there are no data to suggest that novel agents are safer than SPS. Drug choices need to consider costs, access and numbers-needed-to-treat to prevent clinically important events; for potassium exchangers, we need trials directly examining clinically important events.

DIALIZE China: A Phase IIIb, Randomized, Placebo-Controlled Study to Reduce Predialysis Hyperkalemia With Sodium Zirconium Cyclosilicate in Chinese Patients

PURPOSE

The DIALIZE China study (Reduce Incidence of Pre-Dialysis Hyperkalaemia With Sodium Zirconium Cyclosilicate in Chinese Subjects) (NCT04217590) evaluated sodium zirconium cyclosilicate (SZC) for the management of hyperkalemia in Chinese patients undergoing hemodialysis.

METHODS

In the double-blind, Phase IIIb DIALIZE China study, Chinese adults with kidney failure and predialysis hyperkalemia (predialysis serum potassium [sK+] concentration >5.4 mmol/L after the long interdialytic interval [LIDI] and >5.0 mmol/L after ≥1 short interdialytic interval) who were receiving hemodialysis 3 times weekly were randomized to placebo or SZC 5 g once daily on nondialysis days. Doses were titrated towards maintaining normokalemia for 4 weeks (titration period) in 5-g increments up to 15 g. Primary efficacy was the proportion of responders during the 4-week evaluation period following the titration period (ie, those with a predialysis sK+ of 4.0-5.0 mmol/L for at least 3 of 4 hemodialysis visits following the LIDI) who did not require urgent rescue therapy.

FINDINGS

Overall, 134 adults (mean [SD] age, 55 [11.3] years) were randomized to SZC or placebo (n = 67 each). There were significantly more responders with SZC (37.3%) versus placebo (10.4%; estimated odds ratio [OR] = 5.10; 95% CI, 1.90-15.12; P < 0.001). The probability of all predialysis sK+ concentrations being 3.5 to 5.5 mmol/L was significantly higher with SZC versus placebo (estimated OR = 6.41; 95% CI, 2.71-15.12; P < 0.001). A greater proportion of patients achieved an sK+ of 3.5 to 5.5 mmol/L on at least 3 of 4 LIDI visits during evaluation with SZC (73.1%) versus placebo (29.9%). Serious adverse events occurred in 9.1% and 11.9% of patients in the SZC and placebo groups, respectively.

IMPLICATIONS

SZC treatment for predialysis hyperkalemia is effective and well tolerated in Chinese patients with kidney failure receiving hemodialysis.

CLINICALTRIALS

gov identifier: NCT04217590.

Rationale and design of CONTINUITY: a Phase 4 randomized controlled trial of continued post-discharge sodium zirconium cyclosilicate treatment versus standard of care for hyperkalemia in chronic kidney disease

Background

Individuals with chronic kidney disease (CKD) hospitalized with hyperkalemia are at risk of hyperkalemia recurrence and re-hospitalization. We present the rationale and design of CONTINUITY, a study to examine the efficacy of continuing sodium zirconium cyclosilicate (SZC)-an oral, highly selective potassium (K⁺) binder-compared with standard of care (SoC) on maintaining normokalemia and reducing re-hospitalization and resource utilization among participants with CKD hospitalized with hyperkalemia.

Methods

This Phase 4, randomized, open-label, multicenter study will enroll adults with Stage 3b-5 CKD and/or estimated glomerular filtration rate <45 mL/min/1.73 m², within 3 months of eligibility screening, hospitalized with a serum potassium (sK⁺) level of >5.0-≤6.5 mmol/L, without ongoing K⁺ binder treatment. The study will include an in-hospital phase, where participants receive SZC for 2-21 days, and an outpatient (post-discharge) phase. At discharge, participants with sK⁺ 3.5-5.0 mmol/L will be randomized (1:1) to SZC or SoC and monitored for 180 days. The primary endpoint is the occurrence of normokalemia at 180 days. Secondary outcomes include incidence and number of hospital admissions or emergency department visits both with hyperkalemia as a contributing factor, and renin-angiotensin-aldosterone system inhibitor down-titration. The safety and tolerability of SZC will be evaluated.Ethics approval has been received from all relevant ethics committees. Enrollment started March 2022 and the estimated study end date is December 2023.

Conclusions

This study will assess the potential of SZC versus SoC in managing people with CKD and hyperkalemia post-discharge.

Trial registration

ClinicalTrials.gov identifier: NCT05347693; EudraCT: 2021-003527-14, registered on 19 October 2021.

Managing Hyperkalemia in the Modern Era: A Case-Based Approach

The last decade has seen tremendous advances in the prevention and treatment of recurrent hyperkalemia. In this narrative review, we aim to highlight contemporary data on key areas in the epidemiology and management of hyperkalemia. Focusing on drug-induced hyperkalemia (the implications of renin-angiotensin-aldosterone system inhibitors [RAASi] discontinuation and the role of mineralocorticoid receptor antagonists), newer concurrent therapies that modify potassium handling (sodium-glucose transporter 2 inhibitors [SGLT2i]), the introduction of new treatment agents (oral potassium binding agents), and the controversial role of dietary potassium restriction, we apply recent research findings and review the evidence in a case-based format.

Real-World Modifications of Renin-Angiotensin-Aldosterone System Inhibitors in Patients with Hyperkalemia Initiating Sodium Zirconium Cyclosilicate Therapy: The OPTIMIZE I Study

INTRODUCTION

Hyperkalemia (HK) may result in disruptions of guidelines-concordant renin-angiotensin-aldosterone system inhibitors (RAASi), a standard of care in persons with chronic kidney disease (CKD). Such disruptions-dose reduction or discontinuation-diminish the benefits of RAASi, placing patients at risk of serious events and renal dysfunction. This real-world study evaluated RAASi modifications among patients who initiated sodium zirconium cyclosilicate (SZC) for HK.

METHODS

Adults (≥ 18 years) initiating outpatient SZC (index date) while on RAASi were identified from a large US claims database (January 2018-June 2020). RAASi optimization (maintain same or up-titration of RAASi dosage), non-optimization (down-titration of RAASi dosage or discontinuation), and persistence were descriptively summarized following index. Predictors of RAASi optimization were assessed using multivariable logistic regression models. Analyses were conducted by subgroups, including patients without end-stage kidney disease (ESKD), with CKD, and with CKD + diabetes.

RESULTS

A total of 589 patients initiated SZC during RAASi therapy (mean age 61.0 years, 65.2% male), and 82.7% patients (n = 487) kept RAASi after index (mean follow-up  = 8.1 months). Most patients (77.4%) optimized RAASi therapy after initiating SZC; 69.6% maintained the same dosage while 7.8% had up-titrations. A similar rate of RAASi optimization was observed among subgroups without ESKD (78.4%), with CKD (78.9%), and with CKD + diabetes (78.1%). At 1-year post-index, 73.9% of all patients who optimized RAASi were still on therapy, while only 17.9% of patients who did not optimize therapy were still on a RAASi. Among all patients, predictors of RAASi optimization included fewer prior hospitalizations (odds ratio = 0.79, 95% CI [0.63-1.00]; p < 0.05) and fewer prior emergency department (ED) visits (0.78 [0.63-0.96]; p < 0.05).

CONCLUSION

Consistent with clinical trial findings, nearly 80% of patients who initiated SZC for HK optimized their RAASi therapy. Patients may require long-term SZC therapy to encourage continuation of RAASi therapy especially after inpatient and ED visits.

Evaluation of the effect of sodium zirconium cyclosilicate on arrhythmia-related cardiovascular outcomes in patients receiving chronic haemodialysis with hyperkalaemia: protocol for the multicentre, randomised, controlled DIALIZE-Outcomes study

INTRODUCTION

Patients with kidney failure receiving chronic haemodialysis have elevated risk of arrhythmias potentially increasing the likelihood of sudden cardiac death, stroke and hospitalisation. The DIALIZE study (NCT03303521) demonstrated that sodium zirconium cyclosilicate (SZC) was an efficacious and well-tolerated treatment for predialysis hyperkalaemia in patients undergoing haemodialysis. The DIALIZE-Outcomes study evaluates the effect of SZC on sudden cardiac death and arrhythmia-related cardiovascular outcomes in patients receiving chronic haemodialysis with recurrent hyperkalaemia.

METHODS AND ANALYSIS

International, multicentre, randomised, double-blind, placebo-controlled study conducted at 357 study sites across 25 countries. Adults (≥18 years) receiving chronic haemodialysis three times per week with recurrent predialysis serum potassium (K+) ≥5.5 mmol/L post long interdialytic interval (LIDI) are eligible. Patients (~2800) will be randomised 1:1 to SZC or placebo, starting at 5 g orally once daily on non-dialysis days and titrated weekly in 5 g increments (maximum 15 g) to target predialysis serum K+ 4.0-5.0 mmol/L post LIDI. The primary objective is to evaluate efficacy of SZC versus placebo in reducing occurrence of the primary composite endpoint of sudden cardiac death, stroke or arrhythmia-related hospitalisation, intervention or emergency department visit. Secondary endpoints include efficacy of SZC versus placebo in maintaining normokalaemia (serum K+ 4.0-5.5 mmol/L post LIDI) at the 12-month visit, preventing severe hyperkalaemia (serum K+ ≥6.5 mmol/L post LIDI) at the 12-month visit and reducing the incidence of individual cardiovascular outcomes. Safety of SZC will be evaluated. The study is event driven, with participants remaining in the study until 770 primary endpoint events have occurred. Average time in the study is expected to be ~25 months.

ETHICS AND DISSEMINATION

Approval was obtained from the relevant institutional review board/independent ethics committee from each participating site (approving bodies in supplementary information). The results will be submitted to a peer-reviewed journal.

TRIAL REGISTRATION NUMBERS

EudraCT 2020-005561-14 and clinicaltrials.gov identifier NCT04847232.

In pursuit of balance: renin-angiotensin-aldosterone system inhibitors and hyperkalaemia treatment

Hyperkalaemia is a life-threatening condition leading to significant morbidity and mortality. It is common in heart failure (HF) patients due to the disease itself, which often co-exists with chronic kidney disease and diabetes mellitus, the fluctuations in renal function, and the use of some drugs [i.e. renin-angiotensin-aldosterone system (RAAS) inhibitors]. In particular, hyperkalaemia opposes to their administration or up-titration, thus impacting on mortality. New K+ binders, namely, patiromer and sodium zirconium cyclosilicate, are an intriguing option to manage hyperkalaemia in HF patients, both to reduce its fatal effects and to let clinicians up-titrate RAAS inhibitors. Even if their real impact on strong outcomes is still to be determined, we hereby provide an overview of hyperkalaemia in HF and its current management. New trials are welcome to fill the gap in knowledge.

Outcomes in patients with cardiometabolic disease who develop hyperkalemia while treated with a renin-angiotensin-aldosterone system inhibitor

BACKGROUND

Many patients with indications for renin-angiotensin-aldosterone system inhibitor (RAASi) therapy are not receiving these medications. Concern about hyperkalemia is thought to contribute to this lack of evidence-based therapy.

METHODS

A retrospective cohort study included adult patients in primary care practices affiliated with an integrated health care delivery system treated with RAASi between 2000 and 2019 for any of the following indications: (a) coronary artery disease (CAD); (b) heart failure (HF) with a left ventricle ejection fraction ≤ 40%; (c) diabetes mellitus (DM) with proteinuria; or (d) chronic kidney disease (CKD) with proteinuria. Relationship between hyperkalemia (K > 5.0 mEg/L) over the first 12 months of follow-up and a composite end point of cardiovascular events, renal dysfunction, and all-cause mortality was evaluated.

RESULTS

Among 82,732 study patients, 7,727 (9.34%) developed hyperkalemia. Patients with hyperkalemia were older (69.0 vs 64.6) and more likely to have CAD (57.8 vs 53.7%), CKD (57.3 vs 51.1%), HF (19.3 vs 9.7%), and DM (45.3 vs 33.3%) (P < .001 for all). Five-year cumulative risk of the primary outcome was higher in patients who did (63.9%; 95% CI: 62.8%-65.1%) versus did not (37.2%; 95% CI: 36.8%-37.6%) develop hyperkalemia. Five-year cumulative risk of ED visit or hospitalization for hyperkalemia was 15.6% (14.7%-16.6%) for patients with versus 2.7% (95% CI: 2.6-2.9) for patients without hyperkalemia, rising to 25.9% (95% CI: 22.4-29.9) for patients with severe (K > 6.0 mEq/dL) hyperkalemia. Patients who experienced hyperkalemia were more likely (34.4%) than patients who did not (29.2%) to deintensify RAASi therapy (P < .001). Five-year cumulative risk of the primary outcome was higher in patients who lowered RAASi dose (50.4%; 95% CI: 48.5%-52.4%) or stopped RAASi therapy completely (49.3%; 95% CI: 48.5%-50.1%), compared to patients who continued RAASi therapy (36.1%; 95% CI: 25.7-36.5). Similar findings were observed in multivariable analyses and for individual components of the primary outcome.

CONCLUSIONS

Hyperkalemia is a common complication of RAASi therapy and is associated with an increased risk of multiple adverse outcomes. Patients who have their RAASi medications deintensified after a hyperkalemic event have higher incidence of cardiovascular events, renal dysfunction and death.

Sodium polystyrene sulfonate versus sodium zirconium cyclosilicate for the treatment of hyperkalemia in the emergency department

BACKGROUND

Hyperkalemia accounts for over 800,000 emergency department (ED) visits in the United States each year, and has been associated with significant morbidity and mortality likely due to fatal cardiac dysrhythmias. Previous studies have demonstrated reductions in mortality when potassium levels are normalized in the ED. Cation exchange resins, such as sodium polystyrene sulfonate (SPS) and sodium zirconium cyclosilicate (SZC), may be administered as a means of definitively eliminating potassium from the body. This practice is based on physician preference and is not supported by high quality data. Two studies evaluating the use of cation exchange resins versus standard treatment in the ED demonstrated reductions in serum potassium levels within two hours of administration; however, there have been no published studies investigating these agents in a head-to-head comparison.

OBJECTIVE

The purpose of this study was to evaluate the efficacy and safety of SPS versus SZC in lowering serum potassium in patients presenting to the ED with hyperkalemia.

METHODS

This was an institutional review board-approved, retrospective cohort study conducted at a single-site ED. All patients who received medications under the "ED Hyperkalemia Treatment" order set between August 26, 2019 and May 13, 2021 were eligible for inclusion. The primary outcome was the change in serum potassium from baseline to first repeat level following SPS or SZC administration in the ED.

RESULTS

A total of 885 patients were screened with 54 patients in the SPS group and 51 patients in the SZC group included in the final analyses. The mean change in serum potassium from baseline to first repeat level following administration of the cation exchange resin was -1.1 mEq/L for both groups.

CONCLUSION

Administration of SPS or SZC for the treatment of hyperkalemia in the ED resulted in similar reductions in serum potassium.

Prevalence and management of hyperkalemia in chronic kidney disease and heart failure patients in the Gulf Cooperation Council (GCC)

Hyperkalemia is a frequent complication in patients with chronic kidney disease (CKD) or heart failure (HF) and associated with neuromuscular manifestations, changes in the electrocardiogram, and increased risk of mortality. While data on the prevalence and management of hyperkalemia in the gulf region are scarce, risk factors such as preference for potassium-rich foods (e.g., dates and dried fruits/vegetables), periods of intense fasting (e.g., Ramadan), and diabetes (an ancestor of CKD and HF) are common. Therefore, a panel of nephrologists and cardiologists from countries of the Gulf Cooperation Council (GCC) convened to collate and review available data on the prevalence, regional drivers, and current practice in the management of hyperkalemia in the region. Eventually, this review provides consensus recommendations on a balanced utilization of dietary and pharmacological options including new potassium binders for achieving and sustainably maintaining desirable serum potassium levels in countries of the GCC region. Alignment with regional habits and practice was a key aspect to facilitate the uptake of the recommendations into physicians' practice and patients' lives.

An evaluation of sodium zirconium cyclosilicate: a new treatment option for hyperkalaemia in China

INTRODUCTION

Hyperkalemia is a common complication of chronic kidney disease (CKD), diabetes mellitus (DM), and heart failure (HF) that can lead to severe arrhythmias and sudden death and is associated with a higher risk of mortality. Therefore, the prevention and treatment of hyperkalemia is important. Sodium zirconium cyclosilicate (SZC), a new oral potassium-lowering drug, has offered an additional treatment option for Chinese patients with hyperkalemia since its launch in China in late 2019, and some experience has been accumulated regarding its efficacy and safety.

AREAS COVERED

In this review, the authors summarize the epidemiological features of hyperkalemia in China and review the clinical data regarding the use of sodium zirconium cyclosilicate in Chinese patients.

EXPERT OPINION

The prevalence of hyperkalemia is particularly high in Chinese patients with chronic kidney disease and heart failure. In China, recent clinical studies have shown that SZC rapidly reduces serum potassium, maintains normal potassium concentration, and is well tolerated and safe. Two Chinese expert consensus statements have recommended the use of SZC for the acute correction and chronic maintenance of potassium concentration.

Sodium zirconium cyclosilicate and metabolic acidosis: Potential mechanisms and clinical consequences

Metabolic acidosis is frequent in chronic kidney disease (CKD) and is associated with accelerated progression of CKD, hypercatabolism, bone disease, hyperkalemia, and mortality. Clinical guidelines recommend a target serum bicarbonate ≥ 22 mmol/L, but metabolic acidosis frequently remains undiagnosed and untreated. Sodium zirconium cyclosilicate (SZC) binds potassium in the gut and is approved to treat hyperkalemia. In clinical trials with a primary endpoint of serum potassium, SZC increased serum bicarbonate, thus treating CKD-associated metabolic acidosis. The increase in serum bicarbonate was larger in patients with more severe pre-existent metabolic acidosis, was associated to decreased serum urea and was maintained for over a year of SZC therapy. SZC also decreased serum urea and increased serum bicarbonate after switching from a potassium-binding resin in normokalemic individuals. Mechanistically, these findings are consistent with SZC binding the ammonium ion (NH₄⁺) generated from urea by gut microbial urease, preventing its absorption and, thus, preventing the liver regeneration of urea and promoting the fecal excretion of H⁺. This mechanism of action may potentially result in benefits dependent on corrected metabolic acidosis (e.g., improved well-being, decreased catabolism, improved CKD mineral bone disorder, better control of serum phosphate, slower progression of CKD) and dependent on lower urea levels, such as decreased protein carbamylation. A roadmap is provided to guide research into the mechanisms and clinical consequences of the impact of SZC on serum bicarbonate and urate.

Impact on hospitalizations of long-term versus short-term therapy with sodium zirconium cyclosilicate during routine outpatient care of patients with hyperkalemia: the recognize I study

BACKGROUND

Hyperkalemia is associated with increased healthcare resource utilization (HRU). This study evaluated the impact of sodium zirconium cyclosilicate (SZC) use on HRU in outpatients with hyperkalemia.

RESEARCH DESIGN AND METHODS

A retrospective noncomparative study using claims data from the HealthVerity warehouse, which included outpatients in the United States who initiated SZC between January and December 2019 (index date) with ≥6 months' continuous coverage before (baseline) and after (follow-up) the index date (total coverage of 12 months). The study aimed to describe HRU with long-term and short-term SZC (defined as >90 and ≤90 days' supply, respectively, during 180 days' follow-up) and identify characteristics associated with long-term versus short-term therapy.

RESULTS

Of 1153 patients, 748 (64.9%) received short-term and 405 (35.1%) received long-term therapy. During follow-up, lower proportions of patients on long-term versus short-term therapy had hyperkalemia-related hospitalizations (10.1% vs 15.1%; P < 0.05) and all-cause hospitalizations (22.5% vs 29.3%; P < 0.05). Hyperkalemia-related and all-cause hospitalization proportions were 33.0% and 23.3% lower, respectively. Predictors of long-term therapy included stage 3 chronic kidney disease.

CONCLUSIONS

Approximately one-third of patients with hyperkalemia received long-term SZC therapy. Hyperkalemia-related and all-cause hospitalization proportions were lower with long-term therapy, although further confirmatory studies are needed.

Management of Type 2 Diabetic Kidney Disease in 2022: A Narrative Review for Specialists and Primary Care

Purpose of review

Kidney disease is present in almost half of Canadian patients with type 2 diabetes (T2D), and it is also the most common first cardiorenal manifestation of T2D. Despite clear guidelines for testing, opportunities are being missed to identify kidney diseases, and many Canadians are therefore not receiving the best available treatments. This has become even more important given recent clinical trials demonstrating improvements in both kidney and cardiovascular (CV) endpoints with sodium-glucose cotransporter 2 (SGLT2) inhibitors and a nonsteroidal mineralocorticoid receptor antagonist, finerenone. The goal of this document is to provide a narrative review of the current evidence for the treatment of diabetic kidney disease (DKD) that supports this new standard of care and to provide practice points.

Sources of information

An expert panel of Canadian clinicians was assembled, including 9 nephrologists, an endocrinologist, and a primary care practitioner. The information the authors used for this review consisted of published clinical trials and guidelines, selected by the authors based on their assessment of their relevance to the questions being answered.

Methods

Panelists met virtually to discuss potential questions to be answered in the review and agreed on 10 key questions. Two panel members volunteered as co-leads to write the summaries and practice points for each of the identified questions. Summaries and practice points were distributed to the entire author list by email. Through 2 rounds of online voting, a second virtual meeting, and subsequent email correspondence, the authors reached consensus on the contents of the review, including all the practice points.

Key findings

It is critical that DKD be identified as early as possible in the course of the disease to optimally prevent disease progression and associated complications. Patients with diabetes should be routinely screened for DKD with assessments of both urinary albumin and kidney function. Treatment decisions should be individualized based on the risks and benefits, patients' needs and preferences, medication access and cost, and the degree of glucose lowering needed. Patients with DKD should be treated to achieve targets for A1C and blood pressure. Renin-angiotensin-aldosterone system blockade and treatment with SGLT2 inhibitors are also key components of the standard of care to reduce the risk of kidney and CV events for these patients. Finerenone should also be considered to further reduce the risk of CV events and chronic kidney disease progression. Education of patients with diabetes prescribed SGLT2 inhibitors and/or finerenone is an important component of treatment.

Limitations

No formal guideline process was used. The practice points are not graded and are not intended to be viewed as having the weight of a clinical practice guideline or formal consensus statement. However, most practice points are well aligned with current clinical practice guidelines.

Chronic hyperkalemia, diagnosis and management. Colombian consensus

OBJECTIVE

Generate recommendations for the diagnosis, management, and follow-up of chronic hyperkalemia.

METHOD

This consensus was made by nephrologists and cardiologists following the GRADE methodology.

RESULTS

Chronic hyperkalemia can be defined as a biochemical condition with or without clinical manifestations characterized by a recurrent elevation of serum potassium levels that may require pharmacological and or non-pharmacological intervention. It can be classified as mild (K+ 5.0 to < 5.5 mEq/L), moderate (K+ 5.5 to 6.0 mEq/L) or severe (K+ > 6.0 mEq/L). Its incidence and prevalence have yet to be determined. Risk factors: chronic kidney disease, chronic heart failure, diabetes mellitus, age ≥ 65 years, hypertension, and drugs that inhibit the renin angiotensin aldosterone system (RAASi), among others. There is no consensus for the management of chronic hyperkalemia. The suggested pattern for patients is to identify and eliminate or control risk factors, provide advice on potassium intake and, for whom it is indicated, optimize RAASi therapy, administer oral potassium binders and correct metabolic acidosis.

CONCLUSIONS

The recommendation is to pay attention to the diagnosis, management, and follow-up of chronic hyperkalemia, especially in patients with risk factors.

Hyperkalemia: Prevalence, Predictors and Emerging Treatments

It is well established that an elevated potassium level (hyperkalemia) is associated with a risk of adverse events including morbidity, mortality and healthcare system cost. Hyperkalemia is commonly encountered in many chronic conditions including kidney disease, diabetes and heart failure. Furthermore, hyperkalemia may result from the use of renin-angiotensin-aldosterone system inhibitors (RAASi), which are disease-modifying treatments for these conditions. Therefore, balancing the benefits of optimizing treatment with RAASi while mitigating hyperkalemia is crucial to ensure patients are optimally treated. In this review, we will briefly discuss the definition, causes, epidemiology and consequences of hyperkalemia. The majority of the review will be focused on management of hyperkalemia in the acute and chronic setting, emphasizing contemporary approaches and evolving data on the relevance of dietary restriction and the use of novel potassium binders.

Effects of different potassium-lowering regimens on acute hyperkalemia in hemodialysis patients: a real-world, retrospective study

Background

Hyperkalemia is a common and potentially life-threatening electrolyte disorder in maintenance hemodialysis (MHD) patients. This study aimed to evaluate the efficacy and safety of potassium-lowering regimens during treatment of acute hyperkalemia in MHD patients.

Methods

This retrospective real-world study (RWS) was conducted among 139 MHD patients. They were given different potassium-lowering regimens, viz. the insulin and glucose (IG) intravenous administration group (IG, 46 patients), the sodium polystyrene sulfonate group (SPS, 33 patients), the sodium zirconium cyclosilicate group (SZC, 38 patients), the IG + SZC group (22 patients). The primary efficacy end point was the rate of serum potassium decline at 2 h. The rates of adverse events were also compared.

Results

At 2 h, the mean ± SE change of serum potassium level was − 0.71 ± 0.32 mmol per liter (mmol/L) in IG group, − 0.43 ± 0.38 mmol/L in SPS group, − 0.64 ± 0.36 mmol/L in SZC group, − 1.43 ± 0.38 mmol/L in IG + SZC group (P < 0.01). The serum potassium level in IG + SZC group decreased more than that in the other three groups (P < 0.01), while the serum potassium level in SPS group decreased less than that in the other three groups (P < 0.05). There was no significant difference on the decrease of the serum potassium level between IG group and the SZC group (P = 0.374). The IG group and the IG + SZC group had higher rates of symptomatic hypoglycemia. The SPS group had significant decreases of serum calcium and serum magnesium after treatment.

Conclusions

Among MHD patients with acute hyperkalemia, SZC had similar potassium-lowering efficacy with IG intravenous administration at 2 h and superior on convenience and side-effects.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-022-03530-4.

Cost effectiveness of sodium zirconium cyclosilicate for the treatment of hyperkalaemia in patients with CKD in Norway and Sweden

Background

Hyperkalaemia is common in patients with chronic kidney disease (CKD) and is associated with a range of adverse outcomes. Historically, options for management of chronic hyperkalaemia in the outpatient setting have been limited. Novel oral potassium binders provide a safe, effective therapy for maintenance of normokalaemia in patients with CKD, but despite being approved for reimbursement in many countries, prescription data indicate uptake has been slower than anticipated. This analysis aimed to demonstrate the value to patients and the healthcare system of the potassium binder sodium zirconium cyclosilicate (SZC) for treatment of hyperkalaemia in patients with CKD in Norway and Sweden.

Methods

A published simulation model reflecting the natural history of CKD was adapted to the Norwegian and Swedish settings and used to predict long-term health economic outcomes of treating hyperkalaemia with SZC versus usual care.

Results

SZC was highly cost effective compared to usual care in Norway and Sweden, with incremental cost-effectiveness ratios of €14,838/QALY in Norway and €14,352/QALY in Sweden, over a lifetime horizon. The acquisition cost of SZC was largely offset by cost savings associated with reductions in hyperkalaemia events and hospitalisations; a modest overall increase in costs was predominantly attributable to costs associated with gains in life years compared with usual care. SZC remained cost effective in all scenarios examined.

Conclusions

SZC was estimated to be cost effective for treating hyperkalaemia. Consequently, improving access to a clinically effective, safe and cost-effective therapy, such as SZC, may result in considerable benefits for CKD patients with hyperkalaemia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02903-7.

Chronic Hyperkaliemia in Chronic Kidney Disease: An Old Concern with New Answers

Increasing potassium intake ameliorates blood pressure (BP) and cardiovascular (CV) prognoses in the general population; therefore the World Health Organization recommends a high-potassium diet (90–120 mEq/day). Hyperkalaemia is a rare condition in healthy individuals due to the ability of the kidneys to effectively excrete dietary potassium load in urine, while an increase in serum K⁺ is prevalent in patients with chronic kidney disease (CKD). Hyperkalaemia prevalence increases in more advanced CKD stages, and is associated with a poor prognosis. This scenario generates controversy on the correct nutritional approach to hyperkalaemia in CKD patients, considering the unproven link between potassium intake and serum K⁺ levels. Another concern is that drug-induced hyperkalaemia leads to the down-titration or withdrawal of renin-angiotensin system inhibitors (RASI) and mineralocorticoids receptors antagonists (MRA) in patients with CKD, depriving these patients of central therapeutic interventions aimed at delaying CKD progression and decreasing CV mortality. The new K⁺-binder drugs (Patiromer and Sodium-Zirconium Cyclosilicate) have proven to be adequate and safe therapeutic options to control serum K⁺ in CKD patients, enabling RASI and MRA therapy, and possibly, a more liberal intake of fruit and vegetables.