A Randomized Controlled Trial of Fludrocortisone for the Treatment of Hyperkalemia in Hemodialysis Patients

Use of Fludrocortisone for Hyperkalemia in Chronic Kidney Disease Not Yet on Dialysis

Background

Hyperkalemia is a frequent and potentially lethal complication of chronic kidney disease (CKD). We retrospectively examined the potassium-lowering effect of oral fludrocortisone and its adverse effects in hyperkalemic CKD patients not yet on dialysis.

Methods

Thirty-three patients (23 men and 10 women, ages 69±14 years) were included. To control hyperkalemia at the outpatient clinic, twenty-one patients (Group 1) received fludrocortisone (0.05-0.1 mg/day) without changes in angiotensin II receptor blockers (ARBs) and calcium polystyrene sulfonate (CPS), while twelve patients (Group 2) were treated with fludrocortisone in addition to stopping ARBs and/or adding low-dose CPS.

Results

Fludrocortisone was administered for a median of 169 days (interquartile range, 47-445). At the first follow-up after fludrocortisone administration, serum potassium dropped from 6.14±0.32 mEq/L to 4.52±1.06 mEq/L (p<0.001) in Group 1 and from 6.37±0.35 mEq/L to 4.08±0.74 mEq/L (p<0.01) in Group 2. Ten patients in Group 1 and five patients in Group 2 measured serum potassium levels at four outpatient visits before and after fludrocortisone administration, respectively. The frequency of serum potassium ≥6.0 mEq/L decreased from 19/40 (48%) to 2/40 (5%) (p<0.001) in Group 1 and from 11/20 (55%) to 0/20 (0%) (p<0.001) in Group 2. Eleven patients experienced sodium retention-related problems after fludrocortisone administration: 7 with worsening leg edema, 2 with pleural effusions, and 2 with pulmonary edema.

Conclusion

In pre-dialysis CKD patients, fludrocortisone at low doses effectively reduced serum potassium levels; however, sodium retention was a common adverse effect.

Mechanisms and management of drug-induced hyperkalemia in kidney transplant patients

Hyperkalemia is a common and potentially life-threatening complication following kidney transplantation that can be caused by a composite of factors such as medications, delayed graft function, and possibly potassium intake. Managing hyperkalemia after kidney transplantation is associated with increased morbidity and healthcare costs, and can be a cause of multiple hospital admissions and barriers to patient discharge. Medications used routinely after kidney transplantation are considered the most frequent culprit for post-transplant hyperkalemia in recipients with a well-functioning graft. These include calcineurin inhibitors (CNIs), pneumocystis pneumonia (PCP) prophylactic agents, and antihypertensives (angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, beta blockers). CNIs can cause hyperkalemic renal tubular acidosis. When hyperkalemia develops following transplantation, the potential offending medication may be discontinued, switched to another agent, or dose-reduced. Belatacept and mTOR inhibitors offer an alternative to calcineurin inhibitors in the event of hyperkalemia, however should be prescribed in the appropriate patient. While trimethoprim/sulfamethoxazole (TMP/SMX) remains the gold standard for prevention of PCP, alternative agents (e.g. dapsone, atovaquone) have been studied and can be recommend in place of TMP/SMX. Antihypertensives that act on the Renin-Angiotensin-Aldosterone System are generally avoided early after transplant but may be indicated later in the transplant course for patients with comorbidities. In cases of mild to moderate hyperkalemia, medical management can be used to normalize serum potassium levels and allow the transplant team additional time to evaluate the function of the graft. In the immediate post-operative setting following kidney transplantation, a rapidly rising potassium refractory to medical therapy can be an indication for dialysis. Patiromer and sodium zirconium cyclosilicate (ZS-9) may play an important role in the management of chronic hyperkalemia in kidney transplant patients, although additional long-term studies are necessary to confirm these effects.

Sudden cardiac death in dialysis patients: different causes and management strategies

Sudden cardiac death (SCD) represents a major cause of death in end-stage kidney disease (ESKD). The precise estimate of its incidence is difficult to establish because studies on the incidence of SCD in ESKD are often combined with those related to sudden cardiac arrest (SCA) occurring during a haemodialysis (HD) session. The aim of the European Dialysis Working Group of ERA-EDTA was to critically review the current literature examining the causes of extradialysis SCD and intradialysis SCA in ESKD patients and potential management strategies to reduce the incidence of such events. Extradialysis SCD and intradialysis SCA represent different clinical situations and should be kept distinct. Regarding the problem, numerically less relevant, of patients affected by intradialysis SCA, some modifiable risk factors have been identified, such as a low concentration of potassium and calcium in the dialysate, and some advantages linked to the presence of automated external defibrillators in dialysis units have been documented. The problem of extra-dialysis SCD is more complex. A reduced left ventricular ejection fraction associated with SCD is present only in a minority of cases occurring in HD patients. This is the proof that SCD occurring in ESKD has different characteristics compared with SCD occurring in patients with ischaemic heart disease and/or heart failure and not affected by ESKD. Recent evidence suggests that the fatal arrhythmia in this population may be due more frequently to bradyarrhythmias than to tachyarrhythmias. This fact may partly explain why several studies could not demonstrate an advantage of implantable cardioverter defibrillators in preventing SCD in ESKD patients. Electrolyte imbalances, frequently present in HD patients, could explain part of the arrhythmic phenomena, as suggested by the relationship between SCD and timing of the HD session. However, the high incidence of SCD in patients on peritoneal dialysis suggests that other risk factors due to cardiac comorbidities and uraemia per se may contribute to sudden mortality in ESKD patients.

Management of hyperkalemia: A focus on kidney transplant recipients

Hyperkalemia is a frequent complication among kidney transplant recipients that can lead to fatal arrhythmias. The causes of hyperkalemia post kidney transplant are multifactorial and often are drug-induced, and include decreased glomerular filtration rate, tubular dysfunction, and impaired sodium delivery in the distal nephron. This review will discuss pathophysiology and recent updates in the management of both acute and chronic hyperkalemia with a focus on kidney transplant recipients.

Current Management of Hyperkalemia in Patients on Dialysis

Patients with end-stage renal disease (ESRD) on maintenance dialysis have a high risk of developing hyperkalemia, generally defined as serum potassium (K⁺) concentrations of >5.0 mmol/l, particularly those undergoing maintenance hemodialysis. Currently, the key approaches to the management of hyperkalemia in patients with ESRD are dialysis, dietary K⁺ restriction, and avoidance of medications that increase hyperkalemia risk. In this review, we highlight the issues and challenges associated with effective management of hyperkalemia in patients undergoing maintenance dialysis using an illustrative case presentation. In addition, we examine the potential nondialysis options for the management of these patients, including use of the newer K⁺ binder agents patiromer and sodium zirconium cyclosilicate, which may reduce the need for the highly restrictive dialysis diet, with its own implication on nutritional status in patients with ESRD, as well as reducing the risk of potentially life-threatening hyperkalemia.

Barriers to guideline mandated renin-angiotensin inhibitor use: focus on hyperkalaemia

Hyperkalaemia in patients with chronic disease states can be caused by both abnormalities of potassium homeostasis as well as extrinsic factors such as medication use and potassium intake. In patients with heart failure (HF), chronic kidney disease (CKD), diabetes mellitus (DM), and in those who use renin-angiotensin-aldosterone system inhibitors (RAASi), there is particularly increased risk of chronic or recurrent hyperkalaemia. Hyperkalaemia is often a reason for the suboptimal dosing or complete discontinuation of RAASi. This review presents current options for the management of hyperkalaemia in patients with chronic disease states. It also explores barriers to guideline-mediated RAASi prescribing patterns in these high-risk patients and highlights the unmet need for agents that adequately manage hyperkalaemia in patients with chronic diseases on concomitant RAASi therapy.

Efficacy and safety of the pharmacotherapy used in the management of hyperkalemia: a systematic review

BACKGROUND

Although the management of hyperkalemia follows expert guidelines, treatment approaches are based on traditionally accepted practice standards. New drugs have been assessed such as sodium zirconium cyclosilicate and patiromer; however, their safety and efficacy or effectiveness have not yet been compared to traditional pharmacotherapy.

OBJECTIVE

The present systematic review had the purpose to evaluate the efficacy, effectiveness, and safety of hyperkalemia pharmacotherapies.

METHODS

PubMed, LILACS, Cochrane Library, and ClinicalTrials were searched through November 2018. Clinical trial, cohort and case-control were searched. The risk of bias (RoB v2.0 and ROBINS-I) and quality of evidence (GRADE) at the level of outcomes were assessed.

RESULTS

Sixteen clinical trials and one retrospective cohort were identified regarding efficacy and safety of 24 different alternatives. The management of hyperkalemia remains empirical and off-label, since sodium zirconium cyclosilicate and patiromer are not available in several countries and further studies are required to assess efficacy, effectiveness and safety. Sodium or calcium polystyrene sulfonate (moderate confidence), sodium zirconium cyclosilicate (moderate confidence), and insulin plus dextrose (moderate confidence) showed superior efficacy to, respectively, placebo, no treatment, placebo, and dextrose. Other therapies (low confidence) showed similar efficacy compared to active or inactive alternatives. Most of the adverse events reported were nonspecific, so it was not possible to assign the cause and to classify as defined or probable.

CONCLUSIONS

Comparative cohort and case-control studies are need to evaluate the safety and effectiveness of new and traditional pharmacotherapies to support the development of guidelines about acute and chronic hyperkalemia, with high-quality evidence.

Dialysate potassium concentration: Should mass balance trump electrophysiology?

Nephrologists are faced with a difficult dilemma in choosing the ideal dialysis prescription to maintain neutral potassium mass balance. Should potassium mass balance goals prioritize the normalization of serum potassium levels using low potassium dialysate at the expense of provoking intradialytic arrhythmias, or should mass balance goals favor permissive hyperkalemia using higher dialysate potassium to avoid rapid intradialytic fluxes at the risk of more interdialytic arrhythmias? This review examines the factors that determine potassium mass balance among HD patients, the relationships between serum and dialysate potassium levels and outcomes, and concludes by examining currently available approaches to reducing risk of arrhythmias while managing potassium mass balance.

Use of fludrocortisone for intradialytic hypotension

Intradialytic hypotension during dialysis adversely affects a patient’s prognosis and increases mortality. We report a case in which intradialytic hypotension that persisted after the administration of midodrine was relieved after the use of fludrocortisone. Administration of 0.2 mg of fludrocortisone occurred 30 minutes before dialysis. We compared 45 sessions of dialysis without fludrocortisone administration and 45 sessions of dialysis with fludrocortisone administration in one patient. The number of times in which systolic blood pressure became lower than 80 mmHg and the number of early terminations of dialysis due to a decrease in systolic blood pressure were higher in the sessions without fludrocortisone administration than in the sessions with fludrocortisone administration (P < 0.05). Fludrocortisone may be helpful for the treatment of intradialytic hypotension that does not respond to midodrine administration.

How Dangerous Is Hyperkalemia?

Hyperkalemia is a potentially life-threatening electrolyte disorder appreciated with greater frequency in patients with renal disease, heart failure, and with use of certain medications such as renin angiotensin aldosterone inhibitors. The traditional views that hyperkalemia can be reliably diagnosed by electrocardiogram and that particular levels of hyperkalemia confer cardiotoxic risk have been challenged by several reports of patients with atypic presentations. Epidemiologic data demonstrate strong associations of morbidity and mortality in patients with hyperkalemia but these associations appear disconnected in certain patient populations and in differing clinical presentations. Physiologic adaptation, structural cardiac disease, medication use, and degree of concurrent illness might predispose certain patients presenting with hyperkalemia to a lower or higher threshold for toxicity. These factors are often overlooked; yet data suggest that the clinical context in which hyperkalemia develops is at least as important as the degree of hyperkalemia is in determining patient outcome. This review summarizes the clinical data linking hyperkalemia with poor outcomes and discusses how the efficacy of certain treatments might depend on the clinical presentation.

Fludrocortisone therapy for persistent hyperkalaemia

BACKGROUND

Type 4 renal tubular acidosis causes hyperkalaemia, for which diabetes and medications commonly used in this patient group are aetiological factors. Here we describe the novel use of fludrocortisone in this difficult condition.

CASE REPORT

A 55-year-old woman with complex co-morbidities, including Type 2 diabetes (HbA_1c 37 mmol/mol 5.5%), was admitted with renal failure. Bloods on admission: eGFR 25 ml/min, creatinine 184 ?mol/L, urea 35.9 mmol/L, sodium 128 mmol/L, potassium 5.6 mmol/L, bicarbonate 15 mmol/L, and albumin 30 g/L. Her admission was prolonged, complicated by hospital-acquired sepsis (lower respiratory tract, urinary tract, and infected leg ulcers), poor venous access and severe depression. She had recurrent hyperkalaemia and deteriorating renal function, from presumed Type 4 renal tubular acidosis and excessive fluid losses from leg ulcers. Her renal function recurrently deteriorated, despite conventional treatment methods. After 69 days, she was commenced on fludrocortisone 50 mcg/day. Her renal function and serum potassium stabilized and she was discharged with potassium 4.3 mmol/L, eGFR 42 ml/min, and bicarbonate 23 mmol/L. She has remained stable on this treatment, without requiring further hospital admission for over 6 months, with eGFR 40 ml/min, and potassium 5.5 mmol/L, and albumin 26 g/L.

CONCLUSION

This woman was presumed to have Type 4 renal tubular acidosis and recurrent hyperkalaemia due to renal insufficiency, in the context of underlying diabetes and chronic kidney disease, which was poorly responsive to conventional management. There is limited evidence for using fludrocortisone in this setting. Our case suggests that fludrocortisone might offer a novel therapeutic strategy when conventional management is not working.

Evaluation and management of diabetic and non-diabetic hypoglycemia in end-stage renal disease

Patients with end-stage renal disease (ESRD) regardless of diabetes status are at increased risk of hypoglycemia with a resultant array of adverse clinical outcomes. Therefore, hypoglycemia should be thoroughly evaluated in ESRD patients. In diabetic dialysis patients, hypoglycemic agents and nutritional alterations can trigger hypoglycemia in the background of diminished gluconeogenesis, reduced insulin clearance by the kidney and improved insulin sensitivity following initiation of renal replacement therapy. Detailed evaluation of antidiabetic regimen and nutritional patterns, patient education on self-monitoring of blood glucose and/or referral to a diabetes specialist may reduce risk of subsequent hypoglycemia. In certain situations, it is important to recognize the possibility of non-diabetic causes of hypoglycemia in patients with diabetes and to avoid treating pseudo-hyperglycemia caused by glucose- non-specific glucometers in patients utilizing icodextrin-based solutions for peritoneal dialysis. Adrenal insufficiency, certain medications, malnutrition and/or infection are among the most common causes of hypoglycemia in non-diabetic ESRD patients, and they should be suspected after exclusion of inadvertent use of hypoglycemic agents. The goal of this review article is to summarize approaches and recommendations for the work up and treatment of hypoglycemia in ESRD.

Potassium balance in dialysis patients

The advent of dialytic therapy has enabled nephrologists to provide life-saving therapy, but potassium balance continues to be an ever present challenge in the ESRD population. Although a small percent of patients are chronically hypokalemic, hyperkalemia is by far the most common abnormality in dialysis patients. It is associated with increased all-cause mortality, cardiovascular mortality, and arrhythmogenic death. Although alterations of the dialysis bath may decrease predialysis potassium, potassium baths <2 mEq/l are associated with a higher risk of sudden cardiac death. Studies show that patients are aware of the risks of hyperkalemia, but adherence to a low potassium diet is suboptimal. ACEI, ARBs, and spironolactone may cause slight increases in potassium even in anuric patients, requiring increased surveillance. Fludrocortisone and potassium binders have not been proven to be beneficial in lowering interdialytic potassium levels. Frequent hemodialysis may be a viable option, and studies of prophylactic placement of implantable cardioverter/defibrillators are underway.

Sailing between Scylla and Charybdis: the high serum K-low dialysate K quandary

In HD patients, the optimal choice of dialysate K concentration is of paramount importance. Recent large observational studies have documented an association between low dialysate K concentration (< 2 or even <3 mEq/L) and a higher risk of sudden death. In this review, we first briefly discuss the available data concerning the link between hypokalemia and negative outcomes in non-CKD populations, especially after an acute myocardial infarction or in congestive heart failure. We next review the pathophysiology of the arrhythmogenic effect related to K fluxes during HD and discuss the dialytic strategies aiming at making potassium fall more gradual and thus at reducing the electrical disturbances triggered by the HD session. We conclude with practical recommendations regarding the optimal choice of K bath and the importance of more frequent monitoring of serum K in some clinical scenarios.

Potassium handling with dual renin-angiotensin system inhibition in diabetic nephropathy

BACKGROUND AND OBJECTIVES

Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers are the cornerstones of pharmacologic therapy in diabetic nephropathy. Mineralocorticoid receptor blockers reduce proteinuria as single agents or add-on therapy to other renin-angiotensin-aldosterone system-inhibiting drugs in these patients. The long-term benefits and ultimate role of mineralocorticoid receptor blockers in diabetic nephropathy remain unknown. A clinical trial previously showed that the kalemic effect of spironolactone is higher than losartan when added to lisinopril in patients with diabetic nephropathy. The purpose of this study was to investigate if renal potassium handling was primarily responsible for that observation.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In a blinded, randomized, three-arm placebo-controlled clinical trial, 80 participants with diabetic nephropathy taking lisinopril (80 mg) were randomized to spironolactone (25 mg daily), losartan (100 mg daily), or placebo (trial dates from July of 2003 to December of 2006). Serum potassium, aldosterone, and 24-hour urine sodium, potassium, and creatinine were measured over 48 weeks. Differences were analyzed with repeated measures mixed models.

RESULTS

Mean follow-up serum potassium was 5.0 mEq/L for spironolactone, 4.7 mEq/L for losartan (P=0.05 versus spironolactone), and 4.5 mEq/L for placebo (P<0.001 versus spironolactone; P=0.03 versus losartan). The difference in serum potassium was 0.23 mEq/L for losartan versus placebo (P=0.02), 0.43 mEq/L for spironolactone versus placebo (P<0.001), and 0.2 mEq/L for spironolactone versus losartan (P=0.05). Serum and urine potassium excretion and secretion rates were similar between groups throughout the study.

CONCLUSION

Spironolactone raised serum potassium more than losartan in patients with diabetic nephropathy receiving lisinopril, despite similar renal sodium and potassium excretion. This finding suggests that extrarenal potassium homeostasis contributes to hyperkalemia in these patients. A better understanding of extrarenal potassium homeostasis will provide an opportunity to use this drug more safely in patients with diabetic nephropathy as well as other patient populations.

Potassium balances in maintenance hemodialysis

Potassium is abundant in the ICF compartment in the body and its excretion primarily depends on renal (about 90%), and to a lesser extent (about 10%) on colonic excretion. Total body potassium approximated to 50mmol/kg body weight and 2% of total body potassium is in the ECF compartment and 98% of it in the intracellular compartment.Dyskalemia is a frequent electrolyte imbalance observed among the maintenance hemodialysis patients. In case of hyperkalemia, it is frequently "a silent and a potential life threatening electrolyte imbalance" among patients with ESRD under maintenance hemodialysis. The prevalence of hyperkalemia in maintenance HD patients was reported to be about 8.7-10%. Mortality related to the hyperkalemia has been shown to be about 3.1/1,000 patient-years and about 24% of patients with HD required emergency hemodialysis due to severe hyperkalemia. In contrast to the hyperkalemia, much less attention has been paid to the hypokalemia in hemodialysis patients because of the low prevalence under maintenance hemodialysis patients. Severe hypokalemia in the hemodialysis patients usually was resulted from low potassium intake (malnutrition), chronic diarrhea, mineralocorticoid use, and imprudent use of K-exchange resins. Recently, the numbers of the new patients with advanced chronic kidney disease undergoing maintenance hemodialysis are tremendously increasing worldwide. However, the life expectancy of these patients is still much lower than that of the general population. The causes of excess mortality in these patients seem to various, but dyskalemia is a common cause among the patients with ESRD undergoing hemodialysis.

Glycyrrhetinic acid food supplementation lowers serum potassium concentration in chronic hemodialysis patients

Hyperkalemia is a common life-threatening problem in hemodialysis patients. Because glycyrrhetinic acid (GA) inhibits the enzyme 11beta-hydroxy-steroid dehydrogenase II and thereby increases cortisol availability to the colonic mineralocorticoid receptor, it has the potential to lower serum potassium concentrations. To test this, 10 patients in a 6 month prospective, double-blind, placebo-controlled crossover study were given cookies or bread rolls supplemented with glycyrrhetinic acid or placebo. Twenty-four-hour blood pressure measurements were performed at baseline and week 6 and 12 of each treatment period. The ratio of plasma cortisol/cortisone was significantly increased in all patients on GA as compared to baseline or placebo, indicating appropriate enzyme inhibition. Nine of the 10 patients had a persistent decrease in predialysis serum potassium concentration. On GA, mean predialysis serum potassium was significantly lower than at baseline or on placebo. On placebo, serum potassium was significantly elevated above the upper limit of normal in 76% compared to 30% of measurements during GA treatment. Furthermore, on this treatment the frequency of severe hyperkalemia significantly decreased from 9% to 0.6%. No differences were found in parameters reflecting sodium retention. Although these studies show that prolonged GA supplementation persistently lowers serum potassium in dialysis patients, a long-term toxicity study will be mandatory before we recommend the routine use of this treatment.

Management of hyperkalemia in dialysis patients

Hyperkalemia is common in patients with end-stage renal disease, and may result in serious electrocardiographic abnormalities. Dialysis is the definitive treatment of hyperkalemia in these patients. Intravenous calcium is used to stabilize the myocardium. Intravenous insulin and nebulized albuterol lower serum potassium acutely, by shifting it into the cells. Despite their widespread use, neither intravenous bicarbonate nor cation exchange resins are effective in lowering serum potassium acutely. Prevention of hyperkalemia currently rests largely upon dietary compliance and avoidance of medications that may promote hyperkalemia. Prolonged fasting may provoke hyperkalemia, which can be prevented by administration of intravenous dextrose.