Patiromer Lowers Serum Potassium When Taken without Food: Comparison to Dosing with Food from an Open-Label, Randomized, Parallel Group Hyperkalemia Study

Risk of Serious Adverse Gastrointestinal Events with Potassium Binders in Hospitalized Patients: A National Study

BACKGROUND

Concerns about serious adverse gastrointestinal (GI) events with sodium polystyrene sulfonate (SPS) led to development of two new potassium binders, patiromer and sodium zirconium cyclosilicate (SZC), for treatment of hyperkalemia.

OBJECTIVE

To compare risk of intestinal ischemia/thrombosis or other serious GI events associated with SPS, patiromer, or SZC in hospitalized patients.

DESIGN

Retrospective cohort study.

PARTICIPANTS

National sample of 3,144,960 veterans hospitalized 2016-2022 in the U.S. Department of Veterans Affairs Healthcare System.

MAIN MEASURES

Demographics, comorbidities, medications and outcomes were ascertained from the VA Corporate Data Warehouse. Exposures were SPS, patiromer, SZC. Outcomes were 30-day intestinal ischemia/thrombosis, and a composite of intestinal ischemia/thrombosis, peptic ulcer/perforation or bowel resection/ostomy.

KEY RESULTS

Potassium binders were used during 39,270 (1.3%) hospitalizations: SPS = 30,040 (1.0%), patiromer = 3,750 (0.1%), and SZC = 5,520 (0.2%). Intestinal ischemia/thrombosis occurred with 106/30,040 (0.4%) SPS, 12/3750 (0.3%) patiromer and 24/5520 (0.4%) SZC, vs. 6998/3,105,650 (0.2%) without potassium binder. Adjusted odds ratios (aOR) were 1.40 [95% CI, 1.16 to 1.69] with SPS, 1.36 [CI, 0.79 to 2.36] with patiromer, and 1.78 [CI, 1.21 to 2.63] with SZC exposures. Composite GI adverse events occurred with 754/30,040 (2.5%) SPS, 96/3750 (2.6%) patiromer, 2.6% SZC, vs. 144/5520 (2.4%) without binder; aOR were 1.00 [CI, 0.94 to 1.08] with SPS, 1.08 [CI, 0.89 to 1.32] with patiromer, and 1.08 [CI, 0.93 to 1.27] with SZC exposures. No statistical difference in intestinal ischemia/thrombosis between each new agent and SPS was seen (p = 0.274 for SPS vs. SZC; p = 0.916 for SPS vs. patiromer).

CONCLUSION

Risk of intestinal ischemia/thrombosis or other serious adverse GI events was low and did not differ across three potassium-binding drugs.

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.

Maintaining Renin-Angiotensin-Aldosterone System Inhibitor Treatment with Patiromer in Hyperkalaemic Chronic Kidney Disease Patients: Comparison of a Propensity-Matched Real-World Population with AMETHYST-DN

INTRODUCTION

Guideline-directed renin-angiotensin-aldosterone system inhibitor (RAASi) therapy is rarely achieved in clinical settings, often due to hyperkalaemia. We assessed the potassium binder, patiromer, on continuation of RAASi therapy in hyperkalaemic patients with chronic kidney disease (CKD) and type 2 diabetes mellitus (T2DM) in the AMETHYST-DN trial, propensity score-matched to a real-world cohort not receiving patiromer (Salford Kidney Study).

METHODS

The phase 2, open-label AMETHYST-DN trial (NCT01371747) randomized 304 adults with CKD on RAASi, T2DM, hyperkalaemia (serum potassium [sK+] >5.0 mEq/L), and hypertension to receive patiromer, 8.4-33.6 g/day for 12 months. Patients underwent propensity score matching for systolic blood pressure (BP), heart failure status, and estimated glomerular filtration rate (eGFR), with 321 patients with CKD, T2DM, hyperkalaemia, and on RAASi from a prospective CKD cohort (Salford Kidney Study). Changes in RAASi utilization, sK+, BP, proteinuria, and eGFR during 12-month follow-up were assessed by Mann-Whitney U or χ2 tests.

RESULTS

Matching produced 135:135 patients with no significant differences in age, sex, systolic BP, sK+, eGFR, or heart failure status, although differences in diastolic BP remained (p < 0.001). After 12 months, 100% of AMETHYST-DN patients receiving patiromer remained on RAASi therapy, whereas 38.5% of the Salford Kidney Cohort discontinued RAASi (p < 0.001); hyperkalaemia contributed in 16% of patients (42% of RAASi discontinuations). Significantly greater reductions in sK+ and BP, but not proteinuria or eGFR, were observed in AMETHYST-DN, compared with Salford Kidney Study patients (p < 0.05).

CONCLUSIONS

These results demonstrate the benefit of patiromer for sK+ management to enable RAASi use while revealing beneficial effects on BP.

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.

Hyperkalemia in CKD: an overview of available therapeutic strategies

Hyperkalemia (HK) is a life-threatening condition that often occurs in patients with chronic kidney disease (CKD). High serum potassium (sKsK) is responsible for a higher risk of end-stage renal disease, arrhythmias and mortality. This risk increases in patients that discontinue cardio-nephroprotective renin-angiotensin-aldosterone system inhibitor (RAASi) therapy after developing HK. Hence, the management of HK deserves the attention of the clinician in order to optimize the therapeutic strategies of chronic treatment of HK in the CKD patient. The adoption in clinical practice of the new hypokalaemic agents patiromer and sodium zirconium cyclosilicate (SZC) for the prevention and chronic treatment of HK could allow patients, suffering from heart failure and chronic renal failure, to continue to benefit from RAASi therapy. We have updated a narrative review of the clear variables, correct definition, epidemiology, pathogenesis, etiology and classifications for HK among non-dialysis CKD (ND CKD) patients. Furthermore, by describing the prognostic impact on mortality and on the progression of renal damage, we want to outline the strategies currently available for the control of potassium (K+) plasma levels.

Using Renin Activity to Guide Mineralocorticoid Receptor Antagonist Therapy in Patients with Low Renin and Hypertension

BACKGROUND

Mineralocorticoid receptor antagonists (MRAs) are often empirically used for patients with low-renin hypertension (LRH) or probable primary aldosteronism (PA) who decline surgery. However, the optimal approach to MRA therapy is unknown. Studies have shown that a rise in renin is an effective biomarker of prevention of cardiovascular complications of PA. This study aimed to determine whether empiric MRA therapy in patients with LRH or probable PA targeting unsuppressed renin is associated with a decrease in blood pressure and/or proteinuria.

METHODS

Retrospective single-center cohort study from 2005 to 2021 included adults with LRH or probable PA (renin activity <1.0 ng/ml/h and detectable aldosterone levels). All patients were empirically treated with an MRA, targeting renin ≥1.0 ng/ml/h.

RESULTS

Out of 39 patients studied, 32 (82.1%) achieved unsuppressed renin. Systolic and diastolic blood pressure decreased from 148.0 and 81.2 to 125.8 and 71.6 mm Hg, respectively (P < 0.001 for both). Similar blood pressure reductions were seen whether patients had high (>10 ng/dl) or low (<10 ng/dl) aldosterone levels. The majority (24/39; 61.5%) of patients had at least one baseline anti-hypertensive medication stopped. Among the six patients who had detectable proteinuria and albumin-to-creatinine (ACR) measurements post-treatment, the mean ACR decreased from 179.0 to 36.1 mg/g (P = 0.03). None of the patients studied had to completely stop treatment due to adverse reactions.

CONCLUSIONS

Empiric MRA therapy in patients with LRH or probable PA targeting unsuppressed renin can safely and effectively improve blood pressure control and reduce proteinuria.

Patiromer Treatment in Patients With CKD, Hyperkalemia, and Hyperphosphatemia: A Post Hoc Analysis of 3 Clinical Trials

RATIONALE & OBJECTIVE

Patients with chronic kidney disease (CKD), hyperkalemia (serum potassium [sK+]>5.0 mEq/L), and hyperphosphatemia experience poor clinical outcomes. Patiromer, a potassium binder that uses calcium as the exchange ion, may also reduce serum phosphorus (sP). We characterized the effect of patiromer on sP in patients with CKD, hyperkalemia, and hyperphosphatemia.

STUDY DESIGN

A post hoc pooled analysis of individual-level data from the AMETHYST-DN, OPAL-HK, and TOURMALINE trials of patiromer.

SETTING & PARTICIPANTS

Patients with CKD and hyperkalemia.

EXPOSURE

Patients treated with patiromer (8.4-33.6 g/day).

OUTCOME

Mean changes from baseline in sP, sK+, serum calcium (sCa2+), and serum magnesium (sMg2+) after 2 and 4 weeks of treatment.

ANALYTICAL APPROACH

Descriptive statistics to summarize pooled data on the study outcomes from the 3 studies.

RESULTS

We included 578 patients in the analysis. Of these participants, 86 patients (14.9%) had baseline hyperphosphatemia of whom 75.6% (65 of 86) had CKD stage 4/5 and 31.1% (153 of 492) with sP≤4.5mg/dL had CKD stage 4/5. Among the patients with elevated sP and sK+at baseline, the mean±SD reduction in sP and sK+after 4 weeks of patiromer treatment was-0.62±1.09mg/dL and-0.71± 0.51 mEq/L, respectively. Additionally, the mean±SD reduction in sMg2+in these patients was -0.25±0.23mg/dL while sCa2+remained unchanged. Both sMg2+and sCa2+remained within the normal range. Patiromer was generally well tolerated, and no serious adverse events were considered related to patiromer.

LIMITATIONS

These were post hoc analyses, no placebo comparison was performed due to the design of the original studies, and the follow-up period was limited to 4 weeks.

CONCLUSIONS

Reductions in sP and sK+to the normal range were observed after 2 weeks of patiromer treatment, and the reduction was sustained during 4 weeks of treatment among patients with non-dialysis-dependent CKD, hyperkalemia, and hyperphosphatemia. Future controlled trials are needed to establish if patiromer is useful to reduce both sK+and sP in hyperkalemic patients with CKD and hyperphosphatemia.

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.

Safety and Efficacy of Patiromer in Hyperkalemic Patients with CKD: A Pooled Analysis of Three Randomized Trials

Background

Hyperkalemia is a common electrolyte abnormality in patients with CKD, which is associated with worse outcomes and limits use of renin-angiotensin-aldosterone system inhibitors (RAASi). This post hoc subgroup analysis of three clinical trials evaluated the efficacy and safety of the sodium-free, potassium-binding polymer, patiromer, for the treatment of hyperkalemia in adults with nondialysis CKD.

Methods

Data from the 4-week treatment periods of AMETHYST-DN, OPAL-HK, and TOURMALINE studies were combined. Patients had baseline diagnosis of CKD, hyperkalemia (serum potassium >5.0 mEq/L), and received patiromer 8.4-33.6 g/day. Patients were stratified by baseline eGFR into two subgroups: severe/end-stage CKD (stage 3b-5; eGFR <45 ml/min per 1.73 m2) and mild/moderate CKD (stage 1-3a; eGFR ≥45 ml/min per 1.73 m2). Efficacy was assessed by the change in serum potassium (mean±SE) from baseline to week 4. Safety assessments included incidence and severity of adverse events (AEs).

Results

Efficacy analyses (n=626; 62% male, mean age 66 years) included 417 (67%) patients with severe/end-stage CKD and 209 (33%) with mild/moderate CKD. Most patients were receiving RAASi therapy at baseline (severe/end-stage CKD 92%; mild/moderate CKD 98%). The mean±SE change in serum potassium (baseline to week 4) was -0.84±0.03 in the severe/end-stage CKD subgroup, and -0.60±0.04 mEq/L in the mild/moderate CKD subgroup. AEs were reported for 40% and 27% patients in the severe/end-stage and mild/moderate CKD subgroups, respectively, with 16% and 12% reporting AEs considered related to patiromer. The most frequent AEs were mild-to-moderate constipation (8% and 3%) and diarrhea (4% and 2%). AEs leading to patiromer discontinuation occurred in 6% and 2% of patients with severe/end-stage CKD, and mild/moderate CKD, respectively.

Conclusions

Patiromer was effective for treatment of hyperkalemia and well tolerated in patients across stages of CKD, most of whom were receiving guideline-recommended RAASi therapy.

Clinical Efficacy, Safety, Tolerability, and Real-World Data of Patiromer for the Treatment of Hyperkalemia

Hyperkalemia remains one of the most difficult consequences of disease state and treatment for patients with chronic kidney disease, heart failure, and diabetes. Controlling hyperkalemia can be difficult, but has become easier with the introduction of novel oral potassium binders. Patiromer was approved in 2015 for the treatment of hyperkalemia by the FDA in the United States. Several pivotal trials proved its efficacy, safety, and improved tolerability compared with previous hyperkalemia treatments. Additionally, many real-world publications and trials have given deeper insights into the capabilities of patiromer. We discuss improved disease state outcomes with combining patiromer with RAASi. This paper will also highlight new trials forthcoming that are highly anticipated to expand the possibilities in using patiromer to improve outcomes and populations.

Optimization of RAASi Therapy with New Potassium Binders for Patients with Heart Failure and Hyperkalemia: Rapid Review and Meta-Analysis

(1) Background: The objective of this rapid review is to assess whether new potassium binders (NPBs) could enable the optimization of RAASi therapy more than usual care or placebo in patients with or at risk of heart failure and hyperkalemia. (2) Methods: We searched for RCTs that included patients with or at risk of hyperkalemia and patients treated with Patiromer or sodium zirconium cyclosilicate (ZSC). The comparators were placebo, usual care, and potassium binders with different doses or different treatment protocols. We searched the Cochrane CENTRAL, MEDLINE, and ClinicalTrials.gov databases. The risk of bias was assessed using the Cochrane risk of bias tool for RCTs. Data were pooled using the random effects model, and the fixed effects model was used for sensitivity analysis. (3) Results: We included 12 studies with 2800 enrolled patients. Only three of these trials (412 patients) were included in the meta-analysis. NPBs seemed to have an effect on the optimization of MRA therapy, with an RR (95% CI) of 1.24 (1.09, 1.42) (moderate certainty evidence); Patiromer seemed to have an effect on MRA optimization, with an RR (95% CI) or 1.25 (1.08, 1.45) (high certainty evidence). ZSC seemed to have no effect on enabling MRA therapy, with an RR (95% CI) of 1.19 (0.89, 1.59) (low certainty evidence). The AEs in HF patients with hyperkalemia treated with Patiromer were GI disorders and hypomagnesemia. ZSC The AEs included chronic cardiac failure, hypokalemia, and edema. (4) Conclusions: This meta-analysis included three studies with a small number of patients and a short follow-up period (1–3 months). The evidence of the effect of NPBs on MRA optimization had a moderate certainty for imprecision. Data on the effect on MRA optimization and less severe AEs in long-term treatment seem to suggest the use of Patiromer for the optimization of MRA therapy in patients with or at risk of heart failure and hyperkalemia. Future adequately powered RCTs are needed to assess the benefits and potential harms of potassium binders.

Binding Potassium to Improve Treatment With Renin-Angiotensin-Aldosterone System Inhibitors: Results From Multiple One-Stage Pairwise and Network Meta-Analyses of Clinical Trials

This manuscript presents findings from the first dichotomous data pooling analysis on clinical trials (CT) regarding the effectiveness of binding potassium. The results emanated from pairwise and network meta-analyses aiming evaluation of response to commercial potassium-binding polymers, that is, to achieve and maintain normal serum potassium (n = 1,722), and the association between this response and an optimal dosing of renin-angiotensin-aldosterone system inhibitors (RAASi) needing individuals affected by heart failure (HF) or resistant hypertension, who may be consuming other hyperkalemia-inducing drugs (HKID) (e.g., β-blockers, heparin, etc.), and frequently are affected by chronic kidney disease (CKD) (n = 1,044): According to the surface under the cumulative ranking area (SUCRA), sodium zirconium cyclosilicate (SZC) (SUCRA >0.78), patiromer (SUCRA >0.58) and sodium polystyrene sulfonate (SPS) (SUCRA <0.39) were different concerning their capacity to achieve normokalemia (serum potassium level (sK+) 3.5-5.0 mEq/L) or acceptable kalemia (sK+ ≤ 5.1 mEq/L) in individuals with hyperkalemia (sK+ >5.1 mEq/L), and, when normokalemia is achieved, patiromer 16.8-25.2 g/day (SUCRA = 0.94) and patiromer 8.4-16.8 g/day (SUCRA = 0.41) can allow to increase the dose of spironolactone up to 50 mg/day in subjects affected by heart failure (HF) or with resistant hypertension needing treatment with other RAASi. The potential of zirconium cyclosilicate should be explored further, as no data exists to assess properly its capacity to optimize dosing of RAASi, contrarily as it occurs with patiromer. More research is also necessary to discern between benefits of binding potassium among all type of hyperkalemic patients, for example, patients with DM who may need treatment for proteinuria, patients with early hypertension, etc. Systematic Review Registration:https://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42020185614, CRD42020185558, CRD42020191430.

Effect of patiromer on serum potassium in hyperkalemic patients with heart failure: Pooled analysis of 3 randomized trials

BACKGROUND

Hyperkalemia (HK) is a serious medical condition that can cause potentially fatal cardiac arrhythmias. Patients with heart failure (HF) are at risk of HK due to underlying chronic kidney disease and use of guideline-recommended renin-angiotensin-aldosterone system inhibitors. Patiromer, a sodium-free, non-absorbed potassium (K⁺) binder, is indicated for the treatment of HK.

OBJECTIVE

To evaluate the consistency of patiromer's effect on lowering serum K⁺ in patients with HF and HK using pooled data from three clinical trials.

METHODS

This post-hoc analysis evaluated the efficacy and safety of patiromer for management of HK over a 4-week treatment period using combined data from three clinical trials (AMETHYST-DN, OPAL-HK and TOURMALINE). Eligible patients had HK (serum K⁺ > 5.0 mEq/L) at study entry. Starting doses of patiromer ranged from 8.4 to 33.6 g/day. In this analysis, efficacy was assessed as the mean (± standard error [SE]) change in serum K⁺ from baseline to Week 4. Safety outcomes evaluated included the incidence and severity of adverse events (AEs) during the 4-week treatment period.

RESULTS

In total, 653 patients who received ≥1 dose of patiromer were evaluable for efficacy (214 diagnosed with HF and 439 without HF). Mean baseline serum K⁺ was 5.4 mEq/L. Patient characteristics were generally similar between the HF and non-HF subgroups. Serum K⁺ decreased to <5.0mEq/L within one week of patients starting patiromer, reaching a nadir after 3 weeks in both the HF and non-HF subgroups (4.59 mEq/L and 4.64 mEq/L, respectively). The mean ± SE change from baseline to Week 4 in serum K⁺ was -0.79 ± 0.06 mEq/L (95% CI: -0.91, -0.68) in patients with HF and - 0.75 ± 0.02 mEq/L (95% CI: -0.79, -0.70) in patients without HF. AEs occurred in 31% of patients with HF and 37% of patients without HF and were mostly mild or moderate in severity. The most common AEs were constipation (HF patients: 7%, non-HF patients: 5%) and diarrhea (HF patients: 2%, non-HF patients: 4%). AEs leading to discontinuation of patiromer occurred in 7% of patients with HF and in 3% of patients without HF.

CONCLUSIONS

In this pooled analysis of patients with HK, patiromer was generally well tolerated and reduced serum K⁺ similarly in patients with and without HF over 4 weeks.

An evaluation of sodium zirconium cyclosilicate as a treatment option for hyperkalemia

INTRODUCTION

Hyperkalemia, defined as serum potassium level > 5.0 mEq/l, is associated with serious cardiac dysrhythmias, sudden death and increased mortality risk. It is common in patients with chronic kidney disease (CKD), diabetes (DM) and heart failure (HF), particularly in those treated with the renin-angiotensin-aldosterone system (RAAS) inhibitors or potassium-sparing diuretics. Although these drugs have documented renal and cardiac protective benefits, frequent hyperkalemia associated with their use often dictates administration of suboptimal doses or their discontinuation altogether. Treatment for chronic hyperkalemia in these settings has been challenging; however, the recent introduction of two new potassium-binding resins has revolutionized our approach to treating hyperkalemia.

AREAS COVERED

We review key clinical data relating to the pharmacokinetics, efficacy and safety of sodium zirconium cyclosilicate (SZC) as a treatment option for hyperkalemia.

EXPERT OPINION

SZC and Patiromer are promising new agents for lowering serum potassium in hyperkalemic patients, including those with CKD, with and without DM or HF, facilitating the use of the RAAS inhibitors for renal and cardiac protection. Recent randomized clinical trials have shown that SZC effectively lowers serum potassium and maintains normokalemia in most hyperkalemic patients. Clinical trials showed that SZC lowers serum potassium within 1 h, although it is not approved for treating acute hyperkalemia. SZC was well tolerated and associated with minimal adverse effects.

Pharmacodynamic effects of the K+ binder patiromer in a novel chronic hyperkalemia model in spontaneously hypertensive rats

Currently described hyperkalemia (HK) animal models are typically acute and cause significant distress and mortality to the animals, warranting new approaches for studying chronic HK in a more appropriate clinical setting. Using the spontaneously hypertensive rat (SHR) model as a more relevant disease template, as well as surgical (unilateral nephrectomy), dietary (3% potassium [K+ ] supplementation), and pharmacological (amiloride) interventions, we were able to stably induce HK on a chronic basis for up to 12 weeks to serum K+ elevations between 8 and 9 mmol/L, with minimal clinical stress to the animals. Short-term proof-of-concept and long-term chronic studies in hyperkalemic SHRs showed concomitant increases in serum aldosterone, consistent with the previously reported relationship between serum K+ and aldosterone. Treatment with the K+ binder patiromer demonstrated that the disease model was responsive to pharmacological intervention, with significant abrogation in serum K+ , as well as serum aldosterone to levels near baseline, and this was consistent in both short-term and long-term 12-week chronic studies. Our results demonstrate the feasibility of establishing a chronic HK disease state, and this novel HK animal model may be suitable for further evaluating the effects of long-term, K+ -lowering therapies on effects such as renal fibrosis and end-organ damage.

The potassium regulator patiromer affects serum and stool electrolytes in patients receiving hemodialysis

Hyperkalemia is a common and an important cause of death in maintenance hemodialysis patients. Here we investigated the effect of patiromer, a synthetic cation exchanger, to regulate potassium homeostasis. Serum and stool electrolytes were measured in 27 anuric patients with hyperkalemia receiving hemodialysis (mainly 2 mEq/L dialysate) during consecutive two weeks of no-treatment, 12 weeks of treatment with patiromer (16.8g once daily), and six weeks of no treatment. The serum potassium decreased from a mean of 5.7 mEq/L pre-treatment to 5.1 mEq/L during treatment and rebounded to 5.4 mEq/L post-treatment. During the treatment phase, serum calcium significantly increased (from 8.9 to 9.1 mg/dL) and serum magnesium significantly decreased (from 2.6 to 2.4 mg/dL) compared to pre-treatment levels. For each one mEg/L increase in serum magnesium, serum potassium increased by 1.07 mEq/L. Stool potassium significantly increased during treatment phase from pre-treatment levels (4132 to 5923 μg/g) and significantly decreased post-treatment to 4246 μg/g. For each one μg/g increase in stool potassium, serum potassium significantly declined by 0.05 mEq/L. Stool calcium was significantly higher during the treatment phase (13017 μg/g) compared to pre-treatment (7874 μg/g) and post-treatment (7635 μg/g) phases. We estimated that 16.8 g of patiromer will increase fecal potassium by 1880 μg/g and reduce serum potassium by 0.5 mEq/L. Thus, there is a complex interaction between stool and blood potassium, calcium and magnesium during patiromer treatment. Long term consequence of patiromer-induced changes in serum calcium and magnesium remains to be studied.

New Treatment Options for Hyperkalemia in Patients with Chronic Kidney Disease

Hyperkalemia may cause life-threatening cardiac and neuromuscular alterations, and it is associated with high mortality rates. Its treatment includes a multifaceted approach, guided by potassium levels and clinical presentation. In general, treatment of hyperkalemia may be directed towards stabilizing cell membrane potential, promoting transcellular potassium shift and lowering total K+ body content. The latter can be obtained by dialysis, or by increasing potassium elimination by urine or the gastrointestinal tract. Until recently, the only therapeutic option for increasing fecal K+ excretion was represented by the cation-exchanging resin sodium polystyrene sulfonate. However, despite its common use, the efficacy of this drug has been poorly studied in controlled studies, and concerns about its safety have been reported. Interestingly, new drugs, namely patiromer and sodium zirconium cyclosilicate, have been developed to treat hyperkalemia by increasing gastrointestinal potassium elimination. These medications have proved their efficacy and safety in large clinical trials, involving subjects at high risk of hyperkalemia, such as patients with heart failure and chronic kidney disease. In this review, we discuss the mechanisms of action and the updated data of patiromer and sodium zirconium cyclosilicate, considering that the availability of these new treatment options offers the possibility of improving the management of both acute and chronic hyperkalemia.

Evolution of Patiromer Use: a Review

PURPOSE OF REVIEW

The purpose of this review is to present data from clinical trials that resulted in the key data supporting the use of patiromer as a potassium binder in clinical practice today.

RECENT FINDINGS

In addition to trials that support the current Food and Drug Administration label and published over the past 3 years, the recently published Spironolactone With Patiromer in the Treatment of Resistant Hypertension in Chronic Kidney Disease (AMBER) trial provides clear benefits of patiromer use in a group of resistant hypertension patients. The AMBER was a phase 2, multicenter, randomized, double-blind, parallel-group, placebo-controlled study that evaluated 295 participants stratified by local serum potassium measurement (4.3 to < 4.7 mmol/L vs 4.7 to 5.1 mmol/L) and history of diabetes and chronic kidney disease. The focus was on enabling participants with resistant hypertension to achieve blood pressure goals by using spironolactone. Additionally, the ongoing Patiromer for the Management of Hyperkalemia in Subjects Receiving RAASi Medications for the Treatment of Heart Failure (DIAMOND) trial is designed to demonstrate how patiromer is an "enabler" of therapies that are needed to either control resistant hypertension or reduce mortality in heart failure but generate hyperkalemia. These and other studies are discussed in detail. Patiromer is one of two new potassium binders that are far better tolerated than the previous agent and can be given chronically to participants who need life-saving therapies but have elevations of potassium into a dangerous range as a consequence.

Cost-Effectiveness Analysis of Patiromer in Combination with Renin-Angiotensin-Aldosterone System Inhibitors for Chronic Kidney Disease in Sweden

OBJECTIVES

Patients with chronic kidney disease (CKD) are commonly treated with renin-angiotensin-aldosterone system inhibitors (RAASi) in order to delay progression of renal disease. However, research has shown that RAASi in CKD patients increases hyperkalaemia (HK) prevalence, which leads to RAASi discontinuation or dose reduction with the loss of benefits on the kidney. Patiromer is a novel therapy for HK treatment and may enable patients to remain on their RAASi regimen. This study aimed to assess the cost-effectiveness of patiromer from a Swedish healthcare perspective.

METHODS

A Markov model was developed to evaluate the economic outcomes of patiromer versus no patiromer in HK patients with stage 3-4 CKD taking RAASi. The model consisted of six health states reflecting disease progression and hospitalisations. The analysis mainly considered clinical data from the OPAL-HK trial and national costs. The main outcomes of interest were incremental costs (euro [EUR] 2016) and quality-adjusted life years (QALYs), discounted at 3%, and the incremental cost-effectiveness ratio (ICER). Extensive uncertainty analyses were performed.

RESULTS

In comparison to no patiromer, a patiromer patient gained 0.14 QALYs and an incremental cost of EUR 6109 (Swedish krona [SEK] 57,850), yielding an ICER of EUR 43,307 (SEK 410,072)/QALY gained. The results were robust to a range of sensitivity analyses. At a willingness-to-pay threshold of EUR 52,804 (SEK 500,000)/QALY, patiromer had a 50% chance of being cost-effective.

CONCLUSIONS

The results indicate that patiromer may demonstrate value for money in Swedish patients with stage 3-4 CKD, by enabling RAASi treatment. However, there is a considerable degree of uncertainty.

Potassium binders for chronic hyperkalaemia in people with chronic kidney disease

BACKGROUND

Hyperkalaemia is a common electrolyte abnormality caused by reduced renal potassium excretion in patients with chronic kidney diseases (CKD). Potassium binders, such as sodium polystyrene sulfonate and calcium polystyrene sulfonate, are widely used but may lead to constipation and other adverse gastrointestinal (GI) symptoms, reducing their tolerability. Patiromer and sodium zirconium cyclosilicate are newer ion exchange resins for treatment of hyperkalaemia which may cause fewer GI side-effects. Although more recent studies are focusing on clinically-relevant endpoints such as cardiac complications or death, the evidence on safety is still limited. Given the recent expansion in the available treatment options, it is appropriate to review the evidence of effectiveness and tolerability of all potassium exchange resins among people with CKD, with the aim to provide guidance to consumers, practitioners, and policy-makers.

OBJECTIVES

To assess the benefits and harms of potassium binders for treating chronic hyperkalaemia among adults and children with CKD.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 10 March 2020 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-randomised controlled studies (quasi-RCTs) evaluating potassium binders for chronic hyperkalaemia administered in adults and children with CKD.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed risks of bias and extracted data. Treatment estimates were summarised by random effects meta-analysis and expressed as relative risk (RR) or mean difference (MD), with 95% confidence interval (CI). Evidence certainty was assessed using GRADE processes.

MAIN RESULTS

Fifteen studies, randomising 1849 adult participants were eligible for inclusion. Twelve studies involved participants with CKD (stages 1 to 5) not requiring dialysis and three studies were among participants treated with haemodialysis. Potassium binders included calcium polystyrene sulfonate, sodium polystyrene sulfonate, patiromer, and sodium zirconium cyclosilicate. A range of routes, doses, and timing of drug administration were used. Study duration varied from 12 hours to 52 weeks (median 4 weeks). Three were cross-over studies. The mean study age ranged from 53.1 years to 73 years. No studies evaluated treatment in children. Some studies had methodological domains that were at high or unclear risks of bias, leading to low certainty in the results. Studies were not designed to measure treatment effects on cardiac arrhythmias or major GI symptoms. Ten studies (1367 randomised participants) compared a potassium binder to placebo. The certainty of the evidence was low for all outcomes. We categorised treatments in newer agents (patiromer or sodium zirconium cyclosilicate) and older agents (calcium polystyrene sulfonate and sodium polystyrene sulfonate). Patiromer or sodium zirconium cyclosilicate may make little or no difference to death (any cause) (4 studies, 688 participants: RR 0.69, 95% CI 0.11, 4.32; I2 = 0%; low certainty evidence) in CKD. The treatment effect of older potassium binders on death (any cause) was unknown. One cardiovascular death was reported with potassium binder in one study, showing that there was no difference between patiromer or sodium zirconium cyclosilicate and placebo for cardiovascular death in CKD and HD. There was no evidence of a difference between patiromer or sodium zirconium cyclosilicate and placebo for health-related quality of life (HRQoL) at the end of treatment (one study) in CKD or HD. Potassium binders had uncertain effects on nausea (3 studies, 229 participants: RR 2.10, 95% CI 0.65, 6.78; I2 = 0%; low certainty evidence), diarrhoea (5 studies, 720 participants: RR 0.84, 95% CI 0.47, 1.48; I2 = 0%; low certainty evidence), and vomiting (2 studies, 122 participants: RR 1.72, 95% CI 0.35 to 8.51; I2 = 0%; low certainty evidence) in CKD. Potassium binders may lower serum potassium levels (at the end of treatment) (3 studies, 277 participants: MD -0.62 mEq/L, 95% CI -0.97, -0.27; I2 = 92%; low certainty evidence) in CKD and HD. Potassium binders had uncertain effects on constipation (4 studies, 425 participants: RR 1.58, 95% CI 0.71, 3.52; I2 = 0%; low certainty evidence) in CKD. Potassium binders may decrease systolic blood pressure (BP) (2 studies, 369 participants: MD -3.73 mmHg, 95%CI -6.64 to -0.83; I2 = 79%; low certainty evidence) and diastolic BP (one study) at the end of the treatment. No study reported outcome data for cardiac arrhythmias or major GI events. Calcium polystyrene sulfonate may make little or no difference to serum potassium levels at end of treatment, compared to sodium polystyrene sulfonate (2 studies, 117 participants: MD 0.38 mEq/L, 95% CI -0.03 to 0.79; I2 = 42%, low certainty evidence). There was no evidence of a difference in systolic BP (one study), diastolic BP (one study), or constipation (one study) between calcium polystyrene sulfonate and sodium polystyrene sulfonate. There was no difference between high-dose and low-dose patiromer for death (sudden death) (one study), stroke (one study), myocardial infarction (one study), or constipation (one study). The comparative effects whether potassium binders were administered with or without food, laxatives, or sorbitol, were very uncertain with insufficient data to perform meta-analysis.

AUTHORS' CONCLUSIONS

Evidence supporting clinical decision-making for different potassium binders to treat chronic hyperkalaemia in adults with CKD is of low certainty; no studies were identified in children. Available studies have not been designed to measure treatment effects on clinical outcomes such as cardiac arrhythmias or major GI symptoms. This review suggests the need for a large, adequately powered study of potassium binders versus placebo that assesses clinical outcomes of relevance to patients, clinicians and policy-makers. This data could be used to assess cost-effectiveness, given the lack of definitive studies and the clinical importance of potassium binders for chronic hyperkalaemia in people with CKD.

Patiromer for Treatment of Hyperkalemia in the Emergency Department: A Pilot Study

BACKGROUND

Hyperkalemia is common and potentially life threatening. Patiromer is a Food and Drug Administration (FDA)-cleared oral potassium binder effective in the chronic treatment of hyperkalemia.

OBJECTIVE

The objective was to investigate the potential efficacy and safety of oral patiromer in treating acute hyperkalemia in the emergency department (ED).

METHODS

This is a single-center, randomized, open-label convenience sample pilot study in an inner-city ED. Adult patients with end-stage renal disease and a serum potassium level of ≥ 6.0 mEq/L were randomized to standard of care (SOC) or one dose of 25.2 g oral patiromer plus SOC (PAT). Blood samples and electrocardiograms were collected at enrollment and at 1, 2, 4, and 6 hours thereafter. The primary outcome was the difference in potassium between groups at 6 hours. Secondary outcomes were the amount and number of times insulin and albuterol were given.

RESULTS

Thirty patients were included in the final analysis, 15 in each group. There were no differences in age, sex, or baseline serum potassium. There was no difference in mean serum potassium between SOC and PAT groups at 6 hours (6.32 mEq/L, confidence interval [CI] = 6.0 to 6.63 mEq/L vs. 5.81 mEq/L, CI = 5.48 to 6.14 mEq/L). However, 2 hours posttreatment the serum potassium of the PAT group was lower than SOC group (5.90 mEq/L, CI = 5.63 to 6.17 mEq/L vs. 6.51 mEq/L, CI = 6.25 to 6.78 mEq/L) and also 0.61 mEq/L lower than baseline. There were no differences in the amount or number of administrations of insulin or albuterol between groups, although the amount of albuterol used in the PAT group at 6 hours was lower but not significant (median, 0 mg vs. 12.5 mg; p = 0.097). There were no differences in adverse events between groups.

CONCLUSION

In this open-label pilot study of severe hyperkalemia, a single dose of 25.2 g of oral patiromer reduced serum potassium within 2 hours but did not show a difference at 6 hours. This is the first study showing that patiromer may have a role in the acute management of hyperkalemia; however, more rigorous studies are needed.

Patiromer versus placebo to enable spironolactone use in patients with resistant hypertension and chronic kidney disease (AMBER): a phase 2, randomised, double-blind, placebo-controlled trial

BACKGROUND

Spironolactone is effective at reducing blood pressure in patients with uncontrolled resistant hypertension. However, the use of spironolactone in patients with chronic kidney disease can be restricted by hyperkalaemia. We evaluated use of the potassium binder patiromer to allow more persistent use of spironolactone in patients with chronic kidney disease and resistant hypertension.

METHODS

In this phase 2 multicentre, randomised, double-blind, placebo-controlled study, we enrolled participants aged 18 years and older with chronic kidney disease (estimated glomerular filtration rate 25 to ≤45 mL/min per 1·73 m²) and uncontrolled resistant hypertension from 62 outpatient centres in ten countries (Bulgaria, Croatia, Georgia, Hungary, Ukraine, France, Germany, South Africa, the UK, and the USA). Patients meeting all eligibility criteria at the final screening visit were stratified by local serum potassium measurement (4·3 to <4·7 mmol/L vs 4·7 to 5·1 mmol/L) and history of diabetes. Participants were randomly assigned (1:1) with an interactive web response system to receive either placebo or patiromer (8·4 g once daily), in addition to open-label spironolactone (starting at 25 mg once daily) and their baseline blood pressure medications. Participants, the study team that administered treatments and measured blood pressure, and the investigators were masked to assigned treatment groups. Dose titrations were permitted after 1 week (patiromer) and 3 weeks (spironolactone). The primary endpoint was the between-group difference at week 12 in the proportion of patients on spironolactone. Efficacy endpoints and safety were assessed in all randomised patients (intention to treat). The study was registered with Clinicaltrials.gov, NCT03071263.

FINDINGS

Between Feb 13, 2017, and Aug 20, 2018, we screened 574 patients. 295 (51%) of 574 patients met all inclusion criteria and were randomly assigned to spironolactone in addition to double-blind treatment with either placebo (n=148) or patiromer (n=147). At week 12, 98 (66%) of 148 patients in the placebo group and 126 (86%) of 147 patients in the patiromer group remained on spironolactone (between-group difference 19·5%, 95% CI 10·0-29·0; p<0·0001). Adverse events were mostly mild or moderate in severity and occurred in 79 (53%) of 148 patients in the placebo group and 82 (56%) of 147 patients in the patiromer group.

INTERPRETATION

In patients with resistant hypertension and chronic kidney disease, patiromer enabled more patients to continue treatment with spironolactone with less hyperkalaemia. Persistent spironolactone enablement in this population of patients has clinical relevance for the treatment of resistant hypertension.

FUNDING

Relypsa, a Vifor Pharma Group Company.

Treating potassium disturbances: kill the killers but avoid overkill

OBJECTIVES

In this publication, we review the definitions, symptoms, causes, differential diagnoses and therapies of hypokalemia and hyperkalemia.

METHODS

Comprehensive tables and diagnostic algorithms are provided when appropriate.

RESULTS AND CONCLUSIONS

Although both hypokalemia and hyperkalemia may be life-threatening, this is essentially the case with severe changes (serum potassium < 2.5 or > 6.5 mmol/L), the presence of symptoms or electrocardiographic deviations, the association with aggravating factors (e.g. digitalis intake) and/or rapid acute changes. Only these truly need an emergency therapeutic approach. In all other cases, a careful consideration of the causes and their correction should prevail over additional approaches to modify serum potassium concentration. Although most therapeutic approaches to both hypokalemia and hyperkalemia have been well established since many years, recently two new intestinal potassium binders have been introduced on the market. It remains to be elucidated whether these drugs truly have an additional role on top of the existing treatments.

New therapies for hyperkalemia

PURPOSE OF REVIEW

Although renin-angiotensin aldosterone system (RAAS) inhibitors have become the mainstay treatment for patients with chronic diseases, hyperkalemia is a major contributory deterrent to their use in patients with chronic kidney disease (CKD) and heart failure. For the first time in 50 years, two new therapies (patiromer and ZS-9) have recently emerged for the concomitant treatment of hyperkalemia in these patients. The objective of this review is to discuss the efficacy and safety of these new agents.

RECENT FINDINGS

Patiromer effectively reduces serum potassium in patients with CKD and heart failure, even with the concomitant use of RAAS inhibitors. The most common adverse events in clinical trials were gastrointestinal events. ZS-9 (Lokelma) rapidly reduces serum potassium levels and to a greater magnitude, and has a role in the acute management of hyperkalemia. Despite having more adverse events than patiromer, ZS-9 is overall well tolerated.

SUMMARY

These new therapies show promising results for the chronic management of hyperkalemia, whilst also potentially allowing for the concomitant use of RAAS inhibitors at optimal doses. More research is needed to examine the benefits of continuation of RAAS inhibitors after an episode of hyperkalemia in patients with CKD and heart failure.

Effects of the Potassium-Binding Polymer Patiromer on Markers of Mineral Metabolism

BACKGROUND AND OBJECTIVES

Patiromer is a sodium-free, nonabsorbed, potassium-binding polymer that uses calcium as the counter-exchange ion and is approved for treatment of hyperkalemia. The 4-week TOURMALINE study in patients with hyperkalemia previously demonstrated that patiromer administered once daily reduces serum potassium similarly when given with or without food. We report a prespecified exploratory efficacy analysis as well as a post hoc efficacy and safety analysis of the TOURMALINE study on circulating markers of mineral metabolism.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Adults with hyperkalemia (potassium >5.0 mEq/L) were randomized to once-daily patiromer 8.4 g without/with food for 4 weeks, with doses adjusted to achieve and maintain serum potassium 3.8-5.0 mEq/L. Baseline and week 4 serum and 24-hour urine markers of mineral metabolism are reported for all patients combined (evaluable for efficacy, n=112; evaluable for safety, n=113). P values were calculated using a paired t test for change from baseline, unless otherwise specified.

RESULTS

Mean (SD) baseline eGFR was 41±26 ml/min per 1.73 m². Mean (SD) changes from baseline to week 4 were 0.0±0.5 mg/dl (P=0.78; n=100) for albumin-corrected serum calcium, -0.2±0.2 mg/dl (P<0.001; n=100) for serum magnesium, and -0.1±0.7 mg/dl (P=0.47; n=100) for serum phosphate. Median (quartile 1, quartile 3) changes in 24-hour creatinine-normalized urine calcium and phosphate from baseline to week 4 were 2.5 (-11.5, 23.7) mg/24 h (P=0.10; n=69) and -43.0 (-162.6, 35.7) mg/24 h (P=0.004; n=95), respectively. Median (quartile 1, quartile 3) changes in intact parathyroid hormone and 1,25-dihydroxyvitamin D from baseline to week 4 were -13 (-31, 4) pg/ml (P<0.001; n=97) and -2 (-9, 3) pg/ml (P=0.05; n=96), respectively. There were no changes in fibroblast growth factor-23 or 25-hydroxyvitamin D. In patients (n=16) with baseline serum phosphate >4.8 mg/dL, the mean (SD) changes in serum and 24-hour creatinine-normalized urine phosphate from baseline to Week 4 were -0.6±0.8 mg/dl (n=13) and -149.1±162.6 mg/24hr (n=9), respectively.

CONCLUSIONS

Patiromer lowered urine phosphate in all patients, and lowered both serum and urine phosphate in a small subset of patients with hyperphosphatemia. Intact parathyroid hormone and 1,25-dihydroxyvitamin D decreased, with no change in serum calcium.

Effect of Patiromer in Hyperkalemic Patients Taking and Not Taking RAAS Inhibitors

Introduction:

Hyperkalemia (potassium >5.0 mEq/L) affects heart failure patients with renal disease regardless of the use of renin–angiotensin–aldosterone system inhibitors (RAASi). The open-label TOURMALINE study showed that patiromer, a sodium-free, nonabsorbed potassium binder, lowers serum potassium of hyperkalemic patients similarly when given with or without food; unlike prior studies, patients were not required to be taking RAASi. We conducted post hoc analyses to provide the first report of patiromer in patients not taking RAASi.

Methods:

Hyperkalemic patients received patiromer, 8.4 g/d to start, adjusted to achieve and maintain serum potassium of 3.8 to 5.0 mEq/L. If taking RAASi, stable doses were required. The primary end point was the proportion of patients with serum potassium 3.8 to 5.0 mEq/L at week 3 or 4. This analysis presents data by patients taking or not taking RAASi.

Results:

Demographics and baseline characteristics were similar in patients taking (n = 67) and not taking RAASi (n = 45). Baseline mean (SD) serum potassium was 5.37 (0.37) mEq/L and 5.42 (0.43) mEq/L in patients taking and not taking RAASi, respectively. Mean (SD) daily patiromer doses were similar (10.7 [3.2] and 11.5 [4.0] g, respectively). The primary end point was achieved in 85% (95% confidence interval [CI]: 74-93) of patients taking RAASi and in 84% (95% CI: 71-94) of patients not taking RAASi. From baseline to week 4, the mean (SE) change in serum potassium was −0.67 (0.08) mEq/L in patients taking RAASi and −0.56 (0.10) mEq/L in patients not taking RAASi (both P < .0001 vs baseline, P = nonsignificant between groups). Adverse events were reported in 26 (39%) patients taking RAASi and 25 (54%) not taking RAASi; the most common adverse event was diarrhea (2% and 11%, respectively; no cases were severe). Five patients (2 taking RAASi) reported 6 serious adverse events; none considered related to patiromer.

Conclusions:

Patiromer was effective and generally well-tolerated for hyperkalemia treatment, whether or not patients were taking RAAS inhibitors.

The tolerability and safety profile of patiromer: a novel polymer-based potassium binder for the treatment of hyperkalemia

INTRODUCTION

Hyperkalemia (HK) occurs often among patients with chronic kidney disease (CKD) and heart failure (HF) and those treated with renin-angiotensin-aldosterone system inhibitors (RAASI). Even small deviations from normal potassium levels carry increased risk of mortality. Patiromer is approved for treatment of HK and has been shown in clinical trials to reduce serum potassium among patients with HK and comorbid conditions. Areas covered: We review pooled data from two clinical trials of patiromer in patients with CKD and HK, safety of patiromer in special populations, drug-drug interaction (DDI) studies, and other studies in healthy volunteers. Expert opinion: Potassium must be maintained within a narrow range to avoid increased risk of mortality. Patients with CKD and HF and those receiving RAASI require careful monitoring of potassium levels. Patiromer effectively reduces serum potassium, and gastrointestinal adverse events (AEs) are the most common patiromer-associated AEs. Effective management of HK with patiromer may allow use of RAASI at optimal doses as recommended by treatment guidelines. Future research should examine the potential for potassium binders, including patiromer, to extend use of RAASI in appropriate patient populations.