Patiromer for the treatment of hyperkalemia

Vinyl and methyl-ester groups in the insoluble polymer drug patiromer identified and quantified by solid-state NMR

Patiromer (Veltassa®) is a crosslinked, insoluble co-polymer drug used as a nonabsorbent potassium binder, approved for treatment of hyperkalemia. Quantitative solid-state 13C nuclear magnetic resonance (NMR) analysis with comprehensive peak assignment, component quantification, and calculation of mole and weight fractions of monomer units was performed on three doses of patiromer. The workflow is documented in detail. Spectrally edited solid-state 13C NMR spectra of patiromer show =CHn peaks of matching intensity at 116 and 141 ppm, characteristic of -CH=CH2 vinyl groups. Similar spectral features can be observed in earlier studies but were previously ignored. In this study, the vinyl signals are well-resolved in a 2-s direct polarization (DP) spectrum without and with dipolar dephasing, which confirms that these sp2-hybridized carbons are bonded to hydrogen and partially mobile, consistent with vinyl side groups from incompletely reacted divinyl crosslinkers. The vinyl groups account for 1.6% of all carbon, 3% of the monomer units, and nearly 1/3 of the crosslinkers. Furthermore, an unexpected OCH3 moiety accounting for ∼1.2% of all carbons was identified by spectral editing; its chemical shift of 54 ppm is more consistent with a methyl ester than with a methyl ether. It can originate from incomplete hydrolysis of ∼6% of methyl-2-fluoroacrylate, the main monomer of patiromer. Characteristic cross peaks in two-dimensional 1H-13C heteronuclear correlation NMR confirm the presence of the vinyl and OCH3 groups. Trace amounts of xanthan gum are also detected. The quantitative 13C NMR spectrum of patiromer has been matched in a simulation using a model with five monomer units.

Case report: Early molecular confirmation and sodium polystyrene sulfonate management of systemic pseudohypoaldosteronism type I

Introduction

Type 1 pseudohypoaldosteronism (PHA) consists of resistance to aldosterone. Neonatal presentation is characterized by salt wasting, hyperkalemia, and metabolic acidosis with high risk of mortality. Type 1 PHA can be autosomal dominant (renal type 1) or autosomal recessive (systemic type 1). Renal PHA type 1 can be feasibly managed with salt supplementation; however, systemic PHA type 1 tends to have more severe electrolyte imbalance and can be more refractory to treatment.

Case Presentation

We present a case of a 3-year-old girl with systemic PHA type 1, diagnosed and confirmed molecularly in infancy, who has been successfully managed with sodium polystyrene sulfonate decanted into feeds along with sodium supplementation. On day 5 of life, a full-term female infant presented to the ED for 2 days of non-bloody, non-bilious emesis, along with hypothermia to 94°F. Laboratory results were notable for hyponatremia (Na) of 127, hyperkalemia (K) of 7.9, and acidosis with bicarbonate level of 11.2. Genetic testing ordered within a week of life confirmed PHA type 1 with a homozygous pathogenic frameshift variant in SCNN1A c.575delA (p.Arg192GlyfsX57). Sodium polystyrene sulfonate and feeds were decanted until the age of 16 months, and she was also continued on NaCl supplementation. She was gradually transitioned to directly administered sodium polystyrene sulfonate without any electrolyte issues. She has overall done well after gastrostomy-tube (G-tube) placement without severe hyperkalemia even with several hospitalizations for gastrointestinal or respiratory illnesses.

Discussion/Conclusion

A treatment approach to systemic PHA and sodium polystyrene sulfonate administration in neonates and infants is described.

The Efficacy and Safety of Patiromer for Heart Failure Patients: A Systematic Review and Meta-Analysis

PURPOSE

To evaluate the efficacy and safety of patiromer, a novel potassium binder, in reducing the risk of hyperkalemia in patients with heart failure and optimizing their RAASi therapy.

DESIGN

Systematic review and meta-analyses.

METHOD

The authors conducted a systematic search in Pubmed, Embase, Web of Science, and Cochrane Library for randomized controlled trials investigating the efficacy and safety of patiromer in heart failure patients from inception to 31 January 2023 and updated on 25 March 2023. The primary outcome was the association between the reduction of hyperkalemia and patiromer compared with placebo, and the secondary outcome was the association between optimization of RAASi therapy and patiromer.

RESULTS

A total of four randomized controlled trials (n = 1163) were included in the study. Patiromer was able to reduce the risk of hyperkalemia in heart failure patients by 44% (RR 0.56, 95% CI 0.36 to 0.87; I² = 61.9%), improve tolerance to target doses of MRA in patients with heart failure (RR 1.15, 95% CI 1.02 to 1.30; I² = 49.4%), and decrease the proportion of all-cause discontinuation of RAASi (RR 0.49, 95% CI 0.25 to 0.98; I² = 48.4%). However, patiromer therapy was associated with an increased risk of hypokalemia (RR 1.51, 95% CI 1.07 to 2.12; I² = 0%), while no other statistically significant adverse events were observed.

CONCLUSION

Patiromer appears to have a considerable effect on reducing the incidence of hyperkalemia in heart failure patients and on optimizing the therapy of RAASi in those patients.

Safety and efficacy of new potassium binders on hyperkalemia management in patients with heart failure: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Hyperkalemia leads to suboptimal use of evidence-based therapies in patients with heart failure (HF). Therefore, we aimed to assess whether new potassium binders are effective and safe to promote medical optimization in patients with HF.

METHODS

MEDLINE, Cochrane, and Embase were searched for randomized controlled trials (RCTs) that reported outcomes after initiation of Patiromer or Sodium Zirconium Cyclosilicate (SZC) versus placebo in patients with HF at high risk of hyperkalemia development. Risk ratios (RR) with 95% confidence intervals (CI) were pooled with a random effects model. Quality assessment and risk of bias were performed according to Cochrane recommendations.

RESULTS

A total of 1432 patients from 6 RCTs were included, of whom 737 (51.5%) patients received potassium binders. In patients with HF, potassium binders increased the use of renin-angiotensin-aldosterone inhibitors (RR 1.14; 95% CI 1.02-1.28; p = 0.021; I² = 44%) and reduced the risk of hyperkalemia (RR 0.66; 95% CI 0.52-0.84; p < 0.001; I² = 46%). The risk of hypokalemia was significantly increased in patients treated with potassium binders (RR 5.61; 95% CI 1.49-21.08; p = 0.011; I² = 0%). There was no difference between groups in all-cause mortality rates (RR 1.13; 95% CI 0.59-2.16; p = 0.721; I² = 0%) or in adverse events leading to drug discontinuation (RR 1.08; 95% CI 0.60-1.93; p = 0.801; I² = 0%).

CONCLUSION

The use of new potassium binders Patiromer or SZC in patients with HF at risk for hyperkalemia increased the rates of medical therapy optimization with renin-angiotensin-aldosterone inhibitors and reduced the incidence of hyperkalemia, at the cost of an increased prevalence of hypokalemia.

Recent Progresses in Non-Dialysis Chronic Kidney Disease Patients with Hyperkalemia: Outcomes and Therapeutic Strategies

Chronic kidney disease (CKD) affects about 10% of the world's population. Hyperkalemia is a life-threatening complication in patients with CKD, as it is associated with adverse cardiovascular and kidney outcomes. There are still many challenges and questions to address to improve the currently available therapeutic strategies to treat hyperkalemia, such as how to approach the emergency management of hyperkalemia. In recent years, in addition to novel oral potassium binders, great progress has been made in the application of novel kidney protective strategies, such as mineralocorticoid receptor antagonists and sodium-glucose cotransporter 2 inhibitors (SGLT2i) in hyperkalemia therapy. This review will discuss the recent advances from clinical trials in the effective management of hyperkalemia in non-dialysis CKD patients, enhancing the knowledge of physicians and internists concerning these newer agents and providing a helpful reference for clinical practice.

Efficacy and safety of potassium binders in the treatment of patients with chronic kidney disease and hyperkalemia

BACKGROUND

Gastrointestinal cation exchangers that can bind potassium in the gut, including sodium polystyrene sulfonate (SPS), calcium polystyrene sulfonate (CPS), patiromer and sodium zirconium cyclosilicate (SZC), are emerging medications for the treatment of hyperkalemia with chronic kidney disease (CKD). However, which might be the best alternative for patients with chronic kidney disease and hyperkalemia remains disputed.

METHODS

We performed this systematic review and network meta-analysis with the Bayesian approach to conduct direct and indirect comparisons among potassium binders regarding their efficacy and safety. The surface under the cumulative ranking curve analysis (SUCRA) was used to calculate the best intervention for each outcome.

RESULTS

All four potassium binders had a promising effect regarding potassium reduction. SPS had favorable efficacy and safety for short-term use (MD: -0.94; 95% CIs: -1.4 to -0.48; SUCRA = 94.69%), but long-term treatment required strict dose control and assessment of gastrointestinal conditions. CPS had a positive effect on reducing potassium, and could especially maintain the serum potassium concentration in patients receiving renin-angiotensin-aldosterone system inhibitors (RAASi). Patiromer might reduce all-cause mortality in CKD patients with hyperkalemia and have a positive effect on potassium-lowering, though it had significant gastrointestinal adverse effects. SZC had a potassium-lowering effect in both the short-term and long-term, and can be a promising long-term treatment for the hyperkalemia in CKD patients, especially in combination with RAASi.

CONCLUSION

These four potassium binders had their own advantages and disadvantages, and the medication should be selected according to the clinical situation of the patient.

Electrocardiography is Unreliable to Detect Potential Lethal Hyperkalemia in Patients with Non-dialysis Chronic Kidney Disease

Hemodialysis patients with hypercalcemia are less likely to manifest the usual electrocardiographic changes associated with hyperkalemia than in those with normal renal function. This study was conducted to determine whether electrocardiography (ECG) is a reliable indicator to detect severe life-threatening hyperkalemia in non-dialysis CKD patients. The study was conducted at three referral university hospitals between July 2017 and June 2018. Severe hyperkalemia was defined as serum potassium concentration ≥ 8.0 mEq/L. Serum potassium, sodium, bicarbonate, calcium, and creatinine concentrations were measured and simultaneous 12-lead ECG was obtained. Patients with end-stage renal disease receiving renal replacement therapy were excluded. Also excluded were patients with the usual ECG abnormalities to hyperkalemia. Of the 438 patients screened, 10 (2.3%) aged 2-14 years with severe hyperkalemia and normal ECG findings were identified. Median serum potassium level was 8.6 mEq/L (range 8.2-9.0). All had regular sinus rhythm. P, QRS, ST segment, T morphology, PR and QT interval, and QRS duration were all normal. Hyperkalemia was associated with CKD, metabolic acidosis, and hypercalcemia in all cases. Therapy with intravenous 0.9% saline, sodium bicarbonate, glucose, insulin, calcium, and salbutamol corrected the hyperkalemia in 7 patients. The remaining three patients evinced arrhythmias requiring hemodialysis. Although rare, non-dialysis CKD patients with hypercalcemia may not manifest the usual electrographic abnormalities associated with hyperkalemia. Thus, a normal ECG finding in non-dialysis CKD patients should be interpreted with caution.

Hyperkalaemia management and related costs in chronic kidney disease patients with comorbidities in Spain

BACKGROUND

Hyperkalaemia (HK) is a common electrolyte disorder in patients with chronic kidney disease (CKD) and/or treated with renin-angiotensin-aldosterone system inhibitors (RAASis). The aim of this study is to determine the severity, current management and cost of chronic HK.

METHODS

We performed a retrospective cohort study of patients with chronic HK and CKD, heart failure or diabetes mellitus between 2011 and 2018. The study follow-up was 36 months.

RESULTS

A total of 1499 patients with chronic HK were analysed: 66.2% presented with mild HK, 23.4% with moderate HK and 10.4% with severe HK. The severity was associated with CKD stage. Most patients (70.4%) were on RAASi therapies, which were frequently discontinued (discontinuation rate was 39.8, 49.8 and 51.8% in mild, moderate and severe HK, respectively). This RAASi discontinuation was similar with or without resin prescription. Overall, ion-exchange resins were prescribed to 42.5% of patients with HK and prescriptions were related to the severity of HK, being 90% for severe HK. Adherence to resin treatment was very low (36.8% in the first year and 17.5% in the third year) and potassium remained elevated in most patients with severe HK. The annual healthcare cost per patient with HK was €5929, reaching €12 705 in severe HK. Costs related to HK represent 31.9% of the annual cost per HK patient and 58.8% of the specialized care cost.

CONCLUSIONS

HK was usually managed by RAASi discontinuation and ion-exchange resin treatment. Most patients with HK were non-adherent to resins and those with severe HK remained with high potassium levels, despite bearing elevated healthcare expenditures.

Possible Advantages Deriving from Patiromer Use in Hypertensive Patients Made Hyperkalemic by Renin-Angiotensin-Aldosterone Blocking Agents

Hyperkalemia is an elevated level of serum potassium (K⁺) and does represent a life-threatening condition. In clinical practice, hyperkalemia mainly derives from an impaired renal K⁺ excretion which, in turn, is usually caused by either acute or chronic renal failure. In concordance with this, hyperkalemia is very common in several chronic conditions, such as kidney disease, diabetes mellitus, heart failure, hypertension, and coronary heart disease. In all of these conditions the use of Renin-Angiotensin-Aldosterone System inhibitors (RAASIs), such as angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs), and mineralocorticoid receptor antagonist is widely recommended and further increases the risk of hyperkalemia. As hypertension is concerned, clinical trials suggest that the risk of hyperkalemia associated with RAASIs ranges from 2 to 10%. This often leads to a reduction or complete cessation of RAASIs, leaving patients without protective medications. Patiromer, a new oral potassium-binding agent, has been approved for clinical use in several countries, including Europe and US. Clinical studies have demonstrated that patiromer is effective in inducing a rapid and sustained K⁺ reduction in various patient settings, including those where RAASIs are a fundamental component of cardiorenal protection. Patiromer is generally well tolerated and characterised by a good safety profile. Most importantly, patiromer use might allow the continuation of ACEIs and ARBs in hypertensive patients developing hyperkalemia during treatment and thereby favour a more effective and long-lasting cardiorenal protection.

Chronic Kidney Disease: Strategies to Retard Progression

Chronic kidney disease (CKD), defined as the presence of irreversible structural or functional kidney damages, increases the risk of poor outcomes due to its association with multiple complications, including altered mineral metabolism, anemia, metabolic acidosis, and increased cardiovascular events. The mainstay of treatments for CKD lies in the prevention of the development and progression of CKD as well as its complications. Due to the heterogeneous origins and the uncertainty in the pathogenesis of CKD, efficacious therapies for CKD remain challenging. In this review, we focus on the following four themes: first, a summary of the known factors that contribute to CKD development and progression, with an emphasis on avoiding acute kidney injury (AKI); second, an etiology-based treatment strategy for retarding CKD, including the approaches for the common and under-recognized ones; and third, the recommended approaches for ameliorating CKD complications, and the final section discusses the novel agents for counteracting CKD progression.

Inpatient management and post-discharge outcomes of hyperkalemia

OBJECTIVES

Patients with hyperkalemia are commonly treated in the inpatient setting; however, real-world evidence is limited. The purpose of this study was to describe the inpatient management and post-discharge outcomes among patients with hyperkalemia.

METHODS

Electronic medical record data (2012-2018) were used to analyze US adult patients with an inpatient stay with hyperkalemia (≥1 potassium value >5.0mEq/L). Patient characteristics, treatments, and monitoring six months prior to and during the inpatient stay, and hyperkalemia recurrence and inpatient readmissions post-discharge were summarized and compared among patients with mild (>5.0-5.5mEq/L), moderate (>5.5-6.0), and severe (>6.0) hyperkalemia.

RESULTS

Of the 21,793 patients, 69.2% had mild, 19.0% had moderate, and 11.8% had severe hyperkalemia during inpatient care. The most common inpatient treatments were temporizing agents (mild: 28.9%; moderate: 46.0%; severe: 73.0%), diuretics (32.7%; 37.1%; 34.6%), and sodium-polystyrene sulfonate (11.7%; 27.8%; 45.3%). Almost no patients (0.1%) received a potassium binder at discharge. Most patients (86.8%) had their potassium levels return to ≤5.0mEq/L during the inpatient stay. Death during the inpatient stay occurred in 12.3% of mild, 15.5% of moderate, and 19.5% of severe hyperkalemic patients. Within 30 days of discharge, hyperkalemia recurred in 13.3%, 15.4%, and 18.4% of patients with mild, moderate, and severe hyperkalemia, respectively. Additionally, 19.7%, 21.5%, and 19.6% of patients were readmitted to inpatient care within 30 days post-discharge.

CONCLUSION

Among patients with hyperkalemia in the inpatient setting, treatment and normalization of serum potassium levels were common. However, death, readmission, and hyperkalemia recurrence were also fairly common across all cohorts. Future studies examining measures to reduce inpatient death, readmission, and hyperkalemia recurrence among patients with hyperkalemia in inpatient care are warranted.

COVID-19 Extrapulmonary illness - The Impact of COVID-19 on Nephrology care

Coronavirus disease-2019 (COVID-19) has caused a pandemic that has affected millions of people worldwide. COVID-19 is caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and is spread by close contact and by respiratory droplets. It has also impacted different aspects of caring for people with kidney disease, including those with acute kidney injury (AKI), chronic kidney disease (CKD), those requiring kidney replacement therapy (KRT), and those with a kidney transplant. All of these patients are considered high risk. The lessons learned from the COVID-19 pandemic will hopefully serve to protect patients with kidney disease in a similar situation in the future.