Hyperkalemia in the elderly: drugs exacerbate impaired potassium homeostasis

Pseudohyperkalemia in chronic lymphocytic leukemia: Prevalence, impact, and management challenges

The term pseudohyperkalemia refers to a false elevation in serum potassium levels due to potassium release from cells in vitro. Falsely elevated potassium levels have been reported in patients with thrombocytosis, leukocytosis, and hematologic malignancies. This phenomenon has been particularly described in chronic lymphocytic leukemia (CLL). Leukocyte fragility, extremely high leukocyte counts, mechanical stress, higher cell membrane permeability related to an interaction with lithium heparin in plasma blood samples, and metabolite depletion due to a high leukocyte burden have been reported to contribute to pseudohyperkalemia in CLL. The prevalence of pseudohyperkalemia is up to 40%, particularly in the presence of a high leukocyte count (>50 × 109/L). The diagnosis of pseudohyperkalemia is often overlooked, which may result in unnecessary and potentially harmful treatment. The use of whole blood testing and point-of-care blood gas analysis, along with thorough clinical evaluation, may help differentiate between true and pseudohyperkalemic episodes.

Serum Potassium and Risk of Death or Kidney Replacement Therapy in Older People With CKD Stages 4-5: Eight-Year Follow-up

RATIONALE & OBJECTIVE

Hypokalemia may accelerate kidney function decline. Both hypo- and hyperkalemia can cause sudden cardiac death. However, little is known about the relationship between serum potassium and death or the occurrence of kidney failure requiring replacement therapy (KRT). We investigated this relationship in older people with chronic kidney disease (CKD) stage 4-5.

STUDY DESIGN

Prospective observational cohort study.

SETTING & PARTICIPANTS

We followed 1,714 patients (≥65 years old) from the European Quality (EQUAL) study for 8 years from their first estimated glomerular filtration rate (eGFR)<20mL/min/1.73m2 measurement.

EXPOSURE

Serum potassium was measured every 3 to 6 months and categorized as≤3.5,>3.5-≤4.0,>4.0-≤4.5,>4.5-≤5.0 (reference),>5.0-≤5.5, >5.5-≤6.0, and>6.0mmol/L.

OUTCOME

The combined outcome death before KRT or start of KRT.

ANALYTICAL APPROACH

The association between categorical and continuous time-varying potassium and death or KRT start was examined using Cox proportional hazards and restricted cubic spline analyses, adjusted for age, sex, diabetes, cardiovascular disease, renin-angiotensin-aldosterone system (RAAS) inhibition, eGFR, and subjective global assessment (SGA).

RESULTS

At baseline, 66% of participants were men, 42% had diabetes, 47% cardiovascular disease, and 54% used RAAS inhibitors. Their mean age was 76±7 (SD) years, mean eGFR was 17±5 (SD) mL/min/1.73m2, and mean SGA was 6.0±1.0 (SD). Over 8 years, 414 (24%) died before starting KRT, and 595 (35%) started KRT. Adjusted hazard ratios for death or KRT according to the potassium categories were 1.6 (95% CI, 1.1-2.3), 1.4 (95% CI, 1.1-1.7), 1.1 (95% CI, 1.0-1.4), 1 (reference), 1.1 (95% CI, 0.9-1.4), 1.8 (95% CI, 1.4-2.3), and 2.2 (95% CI, 1.5-3.3). Hazard ratios were lowest at a potassium of about 4.9mmol/L.

LIMITATIONS

Shorter intervals between potassium measurements would have allowed for more precise estimations.

CONCLUSIONS

We observed a U-shaped relationship between serum potassium and death or KRT start among patients with incident CKD 4-5, with a nadir risk at a potassium level of 4.9mmol/L. These findings underscore the potential importance of preventing both high and low potassium in patients with CKD 4-5.

PLAIN-LANGUAGE SUMMARY

Abnormal potassium blood levels may increase the risk of death or kidney function decline, especially in older people with chronic kidney disease (CKD). We studied 1,714 patients aged≥65 years with advanced CKD from the European Quality (EQUAL) study and followed them for 8 years. We found that both low and high levels of potassium were associated with an increased risk of death or start of kidney replacement therapy, with the lowest risk observed at a potassium level of 4.9 mmol/L. In patients with CKD, the focus is often on preventing high blood potassium. However, this relatively high optimum potassium level stresses the potential importance of also preventing low potassium levels in older patients with advanced CKD.

Emergency Department Presentation of Life-threatening Symptomatic Hyperkalemia From an Angiotensin Receptor Blocker in a Low-risk Individual

Hyperkalemia is a common electrolyte abnormality with characteristic electrocardiogram changes. Both angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) increase the risk of developing hyperkalemia. This case highlights a rare life-threatening episode of hyperkalemia in an individual whose only risk factor was an ARB. A 58-year-old female presented with sudden-onset chest pressure, light-headedness, and diaphoresis. Her initial electrocardiogram showed a nearly sinusoidal rhythm with a widened ventricular depolarization (QRS) and prolonged QT-interval (QTc). Life-threatening hyperkalemia of 9.1 mmol/L was confirmed with a rapid point-of-care electrolyte panel. She was rapidly treated with calcium, potassium-shifting and eliminating medications, and emergent hemodialysis. After stabilization, a thorough workup found that the patient's only risk factor for hyperkalemia was her use of an ARB. While both ARBs and ACEIs are commonly associated with mild hyperkalemia, life-threatening hyperkalemia is rare, particularly in patients without concomitant renal failure, diabetes mellitus, adrenal disease, or potassium-sparing diuretic use. However, this case illustrates that life-threatening hyperkalemia is possible in patients solely taking an ARB without prior significant risk factors. Despite normal renal function in an individual without heart failure or diabetes, this patient developed life-threatening hyperkalemia.

Resolution of Left Bundle Branch Block After Calcium Administration in the Prehospital Setting

Hyperkalemia is a medical emergency with potentially severe consequences that can be avoided by early recognition and effective treatment. Electrocardiogram (ECG) changes can help elucidate hyperkalemia prior to obtaining lab results and assist in early decisions on treatment, especially in the prehospital setting. ECG changes commonly associated with hyperkalemia are peaked T-waves, PR prolongation, P-wave flattening, QRS widening, or a sine-wave pattern at severely elevated potassium levels. Bundle branch blocks (BBBs) are associated with hyperkalemia but are less common and less well known in this setting. We report a case of a prehospital ECG showing a left bundle branch block (LBBB) in a patient who had end-stage renal disease, and the prehospital treatment with calcium chloride lead to resolution of the LBBB. The patient was eventually found to have a serum potassium level of 6.1 mEq/L.

Acute kidney injury and aging

Our aging population is growing and developing treatments for age-related diseases such as Alzheimer's and Parkinson's disease has taken on an increasing urgency and is accompanied by high public awareness. The already high and rising incidence of acute kidney injury (AKI) in the elderly, however, has received relatively little attention despite the potentially fatal outcomes associated with an episode of AKI in this age group. When discussing AKI and aging, one should consider two aspects: first, elderly patients have an increased susceptibility to an AKI episode, and second, they have decreased kidney repair after AKI given the high incidence of progression to chronic kidney disease (CKD). It is unclear if the same factors that drive the increased susceptibility to AKI could be playing a role in the decreased repair capacity or if they are totally different and unrelated. This review will examine current knowledge on the risk factors for the increased susceptibility to AKI in the elderly and will also explore potential aspects that might contribute to a decreased kidney repair response in this age group.

Hyperkalemia with RAAS inhibition: Mechanism, clinical significance, and management

Renin-angiotensin-aldosterone system (RAAS) inhibitors are evidence-based treatments for a number of conditions including hypertension, diabetes mellitus, chronic kidney disease, and congestive heart failure. Among the most common adverse effects of RAAS inhibitors is hyperkalemia which results from either reduced secretion of aldosterone or increased resistance to aldosterone. Many of the conditions for which RAAS inhibitors are recommended further amplify the risk for hyperkalemia in and of themselves. RAAS inhibitor-related hyperkalemia is associated with an increased risk for cardiovascular events, hospitalizations, and death. Yet discontinuation of RAAS inhibitors for patients with chronic kidney disease and congestive heart failure is also associated with an increased risk for cardiovascular events, hospitalizations, and death. Therefore, clinicians are often left to struggle with the dilemma of the best management approach to RAAS inhibitor-related hyperkalemia. The ideal solution involves pharmacotherapies that are safe and effective in mitigating hyperkalemia and allow patients to continue to receive the beneficial effects from RAAS inhibitors. In this regard, modern pharmacologic agents such as patiromer and zirconium cyclosilicate are providing a mechanism whereby physicians are better equipped to maintain their patients on RAAS inhibitors.

Consensus on the management of hyperkalemia in patients with heart failure: Recommendations from the SEC-SEMI

Use of renin-angiotensin-aldosterone system inhibitors (RAASi) in patients with heart failure (HF) and reduced ejection fraction is associated with functional improvement, an increase in perceived quality of life, a reduction in the probability of cardiovascular death, and a decrease in the number of hospitalizations. Some of these drugs are also efficacious in patients with chronic kidney disease and albuminuria as well as in patients with resistant hypertension. Despite their numerous benefits, RAASi are associated with an increase in incidence of hyperkalemia, especially in patients with concomitant chronic kidney disease. Hyperkalemia is a common electrolyte disorder that is defined as an elevation in plasma concentrations of potassium above 5 mEq/L. It has been related to rehospitalizations, malignant arrhythmias, and an increase in mortality. On the other hand, optimized treatment with RAASi requires progressive dose increases which can in turn entail a greater probability of hyperkalemia. For all of these reasons, it is necessary to establish management and treatment guidelines for these patients. This consensus document arises from this objective. Its recommendations have been developed by a group of ten experts and reviewed by a panel of another ten specialists in the treatment of patients with HF (ten cardiologists and ten internists in total). This document has been endorsed by the Spanish Society of Cardiology (SEC, for its initials in Spanish) and the Spanish Society of Internal Medicine (SEMI, for its initials in Spanish).

Initial and Recurrent Hyperkalemia Events in Patients With CKD in Older Adults: A Population-Based Cohort Study

Background:

The risk of hyperkalemia is elevated in chronic kidney disease (CKD); however, the initial and recurrent risk among older individuals is less clear.

Objectives:

We set out to examine the initial and 1-year recurrent risk of hyperkalemia by level of kidney function (estimated glomerular filtration rate, eGFR) in older adults (≥66 years old).

Design:

Population-based, retrospective cohort study

Settings:

Ontario, Canada

Participants:

905 167 individuals (≥66 years old) from 2008 to 2015.

Measurements:

Serum potassium values

Methods:

Individuals were stratified by eGFR (≥90, 60-89, 30-59, 15-29 mL/min/1.73 m²) and examined for the risk of incident hyperkalemia (K ≥ 5.5 mEq/L) using adjusted Cox proportional hazards models. The 1-year risk of recurrent hyperkalemia was examined using multivariable Andersen-Gill models.

Results:

Among a population of 905 167 individuals (15% eGFR ≥ 90, 58% eGFR 60-89, 25% eGFR 30-59, 3% eGFR 15-29) with a potassium measurement, there were a total of 18 979 (2.1%) individuals with hyperkalemia identified. The event rate (per 1000 person-years) and adjusted hazard ratio (HR) of hyperkalemia was inversely associated with eGFR (mL/min; eGFR >90 mL/min: 8.8, referent, 60-89 mL/min: 11.8 HR 1.41; eGFR 30-59: 39.8, HR 4.37; eGFR 15-29: 133.6, 13.65) and with an increasing urine albumin-to-creatinine ratio (ACR, mg/mmol; ACR< 3: 14, referent, ACR 3-30: 35.1, HR 1.98; ACR >30: 93.7, 4.71). The 1-year event rate and adjusted risk of recurrent hyperkalemia was similarly inversely associated with eGFR (eGFR ≥ 90: 10.1, referent, eGFR 60-89: 14.4, HR 1.47; eGFR 30-59: 54.8, HR 4.90; eGFR 15-29: 208.0, HR 12.98). Among individuals with a baseline eGFR of 30 to 59 and 15 to 29, 0.9 and 3.8% had greater than 2 hyperkalemia events. The relative risk of initial and recurrent hyperkalemia was marginally higher with RAAS blockade. Roughly 1 in 4 individuals with hyperkalemia required hospitalization the day of or within 30 days after their hyperkalemia event.

Limitations:

Limited to individuals aged 66 years and above.

Conclusions:

Patients with low eGFR are at a high risk of initial and recurrent hyperkalemia.

Trial registration:

N/A

Kidney and hypertension in older adults

Individuals over 65years are the fastest expanding population throughout the world, due to the increase in human life expectancy. This growing geriatric population, with increasingly associated chronic diseases, has relevant medical, social, and economic impact. Aging is characterized by progressive structural and functional changes in the kidney and in the cardiovascular system, leading to decline in renal function and hypertension. The purpose of this review is to describe the aging-related renal changes and blood pressure regulation during the aging process, their impact with regards to morbidity and mortality in these patients, and to summarize the most appropriate therapeutic approaches in these situations based on the particularities of this population group.

Hyperkalemia Management in Older Adults With Diabetic Kidney Disease Receiving Renin-Angiotensin-Aldosterone System Inhibitors: A Post Hoc Analysis of the AMETHYST-DN Clinical Trial

Rationale & Objective

Older people are more likely to have reduced kidney function and multiple comorbid conditions predisposing them to hyperkalemia. This post hoc subgroup analysis aimed to evaluate the effectiveness of patiromer, a sodium-free nonabsorbed polymer, in lowering serum potassium levels in older patients receiving a renin-angiotensin-aldosterone system inhibitor with chronic kidney disease (CKD), type 2 diabetes mellitus (T2DM), and hypertension.

Study Design

Post hoc subgroup analysis of the randomized open-label AMETHYST-DN clinical trial.

Setting & Participants

Multicenter clinical trial. Individuals 75 years and older with CKD, T2DM, hypertension, and hyperkalemia at baseline (N = 60; mean age, 77 years; 30 men [50%]; mean estimated glomerular filtration rate, 41.6 ± 14.3 mL/min/1.73 m²).

Intervention

Patients with hyperkalemia were randomly assigned to receive patiromer at doses ranging from 4.2 to 16.8 g twice daily.

Outcomes

We evaluated changesin serum potassium levels from baseline to week 4 and time points through 52 weeks. Long-term safety and tolerability were assessed through the end of 52 weeks and included frequency of adverse events, clinical laboratory measurements, and vital signs.

Results

Of 306 AMETHYST-DN participants, 60 were 75 years or older. All 60 patients had CKD and T2DM; 37% had heart failure. At screening, patients had an estimated glomerular filtration rate of 42 mL/min/1.73 m², median urinary albumin-creatinine ratio of 127 mg/g, and baseline mean serum potassium level of 5.19 mEq/L. Mean serum potassium level was reduced at each time point from the first postbaseline visit (day 3) through week 52.

Limitations

This small subgroup analysis was not prespecified and therefore randomization was lost; thus, it should be considered hypothesis generating.

Conclusions

Among older patients with hyperkalemia and diabetic kidney disease, treatment with patiromer resulted in significant reductions in serum potassium levels after 4 weeks and lasted through 52 weeks. Patiromer was effective in lowering serum potassium levels and was well tolerated in older patients.

Funding

Vifor Pharma, Inc.

Trial Registration

NCT01371747.

Prevalence and economic burden of hyperkalemia in the United States Medicare population

Objective: To estimate the prevalence and economic burden of hyperkalemia in the United States (US) Medicare population.Methods: Patients were selected from a 5% random sample of Medicare beneficiaries (01 January 2010-31 December 2014) to estimate the prevalence and economic burden of hyperkalemia. The prevalence for each calendar year was calculated as the number of patients with hyperkalemia divided by the total number of eligible patients per year. To estimate the economic burden of hyperkalemia, patients with hyperkalemia (cases) were matched 1:1 to patients without hyperkalemia (controls) on age group, chronic kidney disease [CKD] stage, dialysis treatment, and heart failure. The incremental 30-day and 1-year resource utilization and costs (2016 USD) associated with hyperkalemia were estimated.Results: The estimated prevalence of hyperkalemia was 2.6-2.7% in the overall population and 8.9-9.3% among patients with CKD and/or heart failure. Patients with hyperkalemia had higher 1-year rates of inpatient admissions (1.28 vs. 0.44), outpatient visits (30.48 vs. 23.88), emergency department visits (2.01 vs. 1.17), and skilled nursing facility admissions (0.36 vs. 0.11) than the matched controls (all p < .001). Patients with hyperkalemia incurred on average $7208 higher 30-day costs ($8894 vs. $1685) and $19,348 higher 1-year costs ($34,362 vs. $15,013) than controls (both p < .001). Among patients with CKD and/or heart failure, the 30-day and 1-year total cost differences between cohorts were $7726 ($9906 vs. $2180) and $21,577 ($41,416 vs. $19,839), respectively (both p < .001).Conclusions: Hyperkalemia had an estimated prevalence of 2.6-2.7% in the Medicare population and was associated with markedly high healthcare costs.

The Economic Implications of Hyperkalemia in a Medicaid Managed Care Population

BACKGROUND

Hyperkalemia, defined as a serum potassium level >5 mEq/L that results from multiple mechanisms, is a serious medical condition that can lead to life-threatening arrhythmias and sudden cardiac death. The coexistence of cardiac and renal diseases (ie, cardiorenal syndrome) significantly increases the complexity of care, but its economic impact is not well-characterized in this understudied Medicaid managed care population with hyperkalemia.

OBJECTIVE

To calculate the economic impact of hyperkalemia on patients with cardiorenal syndrome in a Medicaid managed care population in the United States using real-world data.

METHODS

In this retrospective cohort study, we used a proprietary Medicaid managed care database from 1 southern state. The total study population included 3563 patients, including 973 patients with hyperkalemia and 2590 controls (without hyperkalemia), who were matched based on age, comorbidities, and Medicaid eligibility status and duration, during a 30-month period between 2013 and 2016. The inclusion criteria for the hyperkalemia cohort were age ≥18 years, Medicaid-only insurance status, coded cardiorenal diagnosis, and a claim for hyperkalemia during the study period. The cost was determined using paid claims data.

RESULTS

The mean healthcare costs (medical and pharmacy per member per year [PMPY] for patients with hyperkalemia was higher than that for the control cohort without hyperkalemia ($56,002 vs $23,653, respectively). These cost differences were driven by medical costs accrued in the hyperkalemia and in the control cohorts ($49,648 and $18,399 PMPY, respectively). Two of the largest drivers of the medical cost variance were inpatient costs ($33,116 vs $10,629 PMPY for the hyperkalemia and control cohorts, respectively) and dialysis costs ($2716 vs $810 PMPY, respectively). The medical loss ratios were 552% for the hyperkalemia cohort and 260% for the control cohort. Both cohorts had revenue deficits to the health plan, but the hyperkalemia cohort had double the medical loss ratio compared with the control cohort.

CONCLUSIONS

The findings from this Medicaid managed care population suggest that hyperkalemia increases healthcare utilization and costs, which were primarily driven by the costs associated with inpatient care and dialysis. Our findings demonstrate that the Medicaid beneficiaries who have cardiorenal comorbidities accrue high costs to the Medicaid health plan, and these costs are even higher if a hyperkalemia diagnosis is present. The very high medical loss ratio for the hyperkalemia cohort in our analysis indicates that enhanced monitoring and management of patients with hyperkalemia should be considered.

Evaluation of context-specific alerts for potassium-increasing drug-drug interactions: A pre-post study

OBJECTIVE

To investigate whether context-specific alerts for potassium-increasing drug-drug interactions (DDIs) in a clinical decision support system reduced the alert burden, increased alert acceptance, and had an effect on the occurrence of hyperkalemia.

MATERIALS AND METHODS

In the pre-intervention period all alerts for potassium-increasing DDIs were level 1 alerts advising absolute contraindication, while in the post-intervention period the same drug combinations could trigger a level 1 (absolute contraindication), a level 2 (monitor potassium values), or a level 3 alert (informative, not shown to physicians) based on the patient's recent laboratory value of potassium. Alert acceptance was defined as non-prescription or non-administration of the interacting drug combination for level 1 alerts and as monitoring of the potassium levels for level 2 alerts.

RESULTS

The alert burden decreased by 92.8%. The relative risk (RR) for alert acceptance based on prescription rates for level 1 alerts and monitoring rates for level 2 alerts was 15.048 (86.5% vs 5.7%; 95% CI 12.037-18.811; P < 0.001). With alert acceptance for level 1 alerts based on actual administration and for level 2 alerts on monitoring rates, the RR was 3.597 (87.6% vs 24.4%; 95% CI 3.192-4.053; P < 0.001). In the generalized linear mixed model the effect of the intervention on the occurrence of hyperkalemia was not significant (OR 1.091, 95% CI 0.172-6.919).

CONCLUSION

The proposed strategy seems effective to get a grip on the delicate balance between over- and under alerting.

Epidemiology of hyperkalemia in chronic kidney disease

BACKGROUND

Hyperkalaemia is a significant electrolyte imbalance in chronic kidney disease (CKD). Renin-angiotensin-aldosterone system inhibitors (RAASi) have beneficial cardio-renal properties, although they can often cause hyperkalaemia.

OBJECTIVE

To examine the prevalence of hyperkalaemia in CKD, identify factors associated with its appearance and the relationship between hyperkalaemia and mortality.

PATIENTS AND METHODS

Retrospective observational study on patients with CKD in the period 1971-2017. The population was categorised into 3groups: Group 1, patients with CKD without renal replacement therapy; Group 2, patients on haemodialysis; and Group 3, patients on continuous ambulatory peritoneal dialysis.

RESULTS

A total of 2,629 patients were evaluated. The prevalence observed in the different groups was: 9.6%, 16.4% and 10.6%, respectively. Risk factors related to the appearance of hyperkalaemia in the CKD group were glomerular filtration rate (GFR) (P<.001), plasma creatinine (P<.001), plasma sodium (P<.001), haemoglobin (P=.028), diastolic blood pressure (P=.012), intake of ACE inhibitors and/or angiotensin ii receptor blockers (P=.008), treatment with metformin (P<.001) and diabetes (P=.045). Treatment with RAASi significantly increased hyperkalaemia as GFR decreased, as well as in patients with diabetes or heart failure.

CONCLUSIONS

Hyperkalaemia is a frequent metabolic alteration in CKD patients that increases in the presence of drugs with beneficial cardio-renal properties (RAASi), which means that patients often lose the benefit associated with these drugs. New, recently-appearing non-absorbable compounds, which bind to potassium in the gastrointestinal tract, enhancing faecal excretion and thus maintaining the cardio-renal benefit of the RAASi, could be relevant in the progress of patients with CKD.

Long-term effects of patiromer for hyperkalaemia treatment in patients with mild heart failure and diabetic nephropathy on angiotensin-converting enzymes/angiotensin receptor blockers: results from AMETHYST-DN

AIMS

Chronic kidney disease (CKD) in heart failure (HF) increases the risk of hyperkalaemia (HK), limiting angiotensin-converting enzyme inhibitor (ACE-I) or angiotensin receptor blocker (ARB) use. Patiromer is a sodium-free, non-absorbed potassium binder approved for HK treatment. We retrospectively evaluated patiromer's long-term safety and efficacy in HF patients from AMETHYST-DN.

METHODS AND RESULTS

Patients with Type 2 diabetes, CKD, and HK [baseline serum potassium >5.0-5.5 mmol/L (mild) or >5.5-<6.0 mmol/L (moderate)], with or without HF (New York Heart Association Class I and II, by investigator judgement), on ACE-I/ARB, were randomized to patiromer 8.4-33.6 g to start, divided twice daily. Overall, 105/304 (35%) patients had HF (75%, Class II). Mean (standard deviation) ejection fraction (EF) was 44.9% (8.2) (n = 81) in patients with HF; 26 had EF ≤40%. In HF patients, mean serum potassium decreased by Day 3 through Week 52. At Week 4, estimated mean (95% confidence interval) change in serum potassium was -0.64 mmol/L (-0.72, -0.55) in mild and -0.97 mmol/L (-1.14, -0.80) in moderate HK (both P < 0.0001). Most HF patients with mild (>88%) and moderate (≥73%) HK had normokalaemia at each visit from Weeks 12 to 52. Three HF patients were withdrawn because of high (n = 1) or low (n = 2) serum potassium. The most common patiromer-related adverse event was hypomagnesaemia (8.6%).

CONCLUSIONS

In patients with a clinical diagnosis of HF, diabetes, CKD, and HK on ACE-I/ARB, patiromer was well tolerated and effective for HK treatment over 52 weeks.

PREVALENCE AND RISK FACTORS OF HYPERKALEMIA AFTER LIVER TRANSPLANTATION

BACKGROUND

There is a lack of data regarding hyperkalemia after liver transplantation.

AIM

To evaluate the prevalence of hyperkalemia after liver transplantation and its associated factors.

METHODS

This retrospective cohort study evaluated 147 consecutive post-transplant patients who had at least one year of outpatient medical follow up. The data collection included gender, age, potassium values, urea, creatinine, sodium and medication use at 1, 6 and 12 months after. Hyperkalemia was defined as serum potassium concentrations higher than 5.5 mEq/l.

RESULTS

Hiperkalemia was observed in 18.4%, 17.0% and 6.1% of patients 1, 6 and 12 months after tranplantation, respectively. Older age (p=0.021), low creatinine clearance (p=0.007), increased urea (p=0.010) and hypernatremia (p=0.014) were factors associated with hyperkalemia, as well as the dose of prednisone at six months (p=0.014).

CONCLUSION

Hyperkalemia was prevalent in less than 20% of patients in the 1st month after liver transplantation and decreased over time. Considering that hyperkalemia does not affect all patients, attention should be paid to the routine potassium intake recommendations, and treatment should be individualized.

DOPPS data suggest a possible survival benefit of renin angiotensin-aldosterone system inhibitors and other antihypertensive medications for hemodialysis patients

The benefits of renin angiotensin-aldosterone system inhibitors (RAASi) are well-established in the general population, particularly among those with diabetes, congestive heart failure (CHF), or coronary artery disease (CAD). However, conflicting evidence from trials and concerns about hyperkalemia limit RAASi use in hemodialysis patients, relative to other antihypertensive agents, including beta blockers and calcium channel blockers. Therefore, we investigated prescription patterns and associations with mortality for RAASi and other antihypertensive agents using data from the international Dialysis Outcomes and Practice Patterns Study (DOPPS). Cox regression was used to estimate the effect of the prescription of RAASi and other antihypertensive agents at study entry on mortality in 11,421 incident (120 days or less) hemodialysis and 37,124 prevalent (over 120 days) hemodialysis patients from DOPPS phases 2-5 (2002-2015). Over 95% of RAASi were angiotensin-converting enzyme inhibitors or angiotensin receptor blockers. RAASi prevalence was 39% and varied minimally by CHF and CAD. The adjusted hazard ratio for RAASi (vs. no RAASi) was 0.89 (95% confidence interval 0.80-0.99) among incident and 0.94 (0.90-0.99) among prevalent hemodialysis patients, with no convincing evidence of interaction with diabetes, CAD or CHF. Inverse associations with mortality were also observed for beta blockers and calcium channel blockers, and were stronger for angiotensin receptor blockers than angiotensin-converting enzyme inhibitors, but this latter finding requires further study. Thus, our observations suggest a relatively small survival benefit of RAASi and other antihypertensive agents in hemodialysis patients, though randomized prospective studies are needed to potentially change prescribing criteria.

Effect of Patiromer on Hyperkalemia Recurrence in Older Chronic Kidney Disease Patients Taking RAAS Inhibitors

BACKGROUND

Older people are predisposed to hyperkalemia because of impaired renal function, comorbid conditions, and polypharmacy. Renin-angiotensin-aldosterone system inhibitors (RAASi), which are recommended to treat chronic kidney disease and heart failure augment the risk. Patiromer, a nonabsorbed potassium binder, was shown in the phase 3 OPAL-HK study to decrease serum potassium in patients with chronic kidney disease taking RAASi. We studied the efficacy and safety of patiromer in a prespecified subgroup of patients aged ≥65 years from OPAL-HK.

METHODS

Chronic kidney disease patients with mild or moderate-to-severe hyperkalemia received patiromer, initially 8.4 g/d or 16.8 g/d, respectively, for 4 weeks (treatment phase, part A). Eligible patients entered an 8-week randomized withdrawal phase (part B) and continued patiromer or switched to placebo.

RESULTS

Mean ± standard error change in serum potassium from baseline to week 4 of part A (primary endpoint) in patients aged ≥65 years was -1.01 ± 0.05 mEq/L (P < .001); 97% achieved serum potassium 3.8-<5.1 mEq/L. The serum potassium increase during the first 4 weeks of part B was greater in patients taking placebo than in those taking patiromer (P < .001). Fewer patients taking patiromer (30%) than placebo (92%) developed recurrent hyperkalemia (serum potassium ≥5.1 mEq/L). Mild-to-moderate constipation occurred in 15% (part A) and 7% (part B) of patients aged ≥65 years. Serum potassium <3.5 mEq/L and serum magnesium <1.4 mg/dL were infrequent (4% each in patients aged ≥65 years in part A).

CONCLUSIONS

Patiromer reduced recurrent hyperkalemia and was well tolerated in older chronic kidney disease patients taking RAASi.

Incidence of and Risk Factors for Severe Adverse Events in Elderly Patients Taking Angiotensin-Converting Enzyme Inhibitors or Angiotensin II Receptor Blockers after an Acute Myocardial Infarction

STUDY OBJECTIVE

To assess the incidence of and risk factors associated with severe adverse events in elderly patients who used angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin II receptor blockers (ARBs) after an acute myocardial infarction (AMI).

DESIGN

Retrospective cohort study.

DATA SOURCES

Centers for Medicare & Medicaid Services Chronic Conditions Data Warehouse (Medicare service claims database), American Community Survey of the U.S. Census Bureau, and Multum Lexicon Drug database.

PATIENTS

A total of 101,588 eligible Medicare fee-for-service beneficiaries 66 years or older, who were hospitalized for AMI between January 1, 2008, and December 31, 2009, and used ACEIs or ARBs within 30 days after discharge.

MEASUREMENTS AND MAIN RESULTS

Primary outcomes were hospitalizations for acute renal failure (ARF) and hyperkalemia. The secondary outcome was discontinuation or suspension of ACEI/ARB therapy after a visit to a health care provider. The primary risk factors of interest were age, sex, race/ethnicity, and chronic kidney disease (CKD). Cumulative incidence curves and multivariable Fine-Gray proportional hazards models with 95% confidence intervals (CIs) were used with death as a competing risk in both intention-to-treat (ITT) and as-treated (AT) analyses. In the study cohort, 2.8% experienced ARF, 0.5% experienced hyperkalemia, and 63.7% discontinued ACEI/ARB therapy within 1 year after hospital discharge. Approximately half of the incidence of ARF and hyperkalemia occurred within 6 months after hospital discharge, but the cumulative incidence increased after 6 months. Patients older than 85 years had a higher rate of ARF (ITT hazard ratio [HR] 1.15, 95% CI 1.04-1.28) and hyperkalemia (ITT HR 1.33, 95% CI 1.05-1.68) compared with those aged 65-74 years. Patients with baseline CKD had higher rates of ARF (ITT HR 1.61, 95% CI 1.42-1.82), hyperkalemia (ITT HR 1.41, 95% CI 1.11-1.77), and ACEI/ARB therapy discontinuation or suspension (ITT HR 1.05, 95% CI 1.02-1.09).

CONCLUSION

We found a low incidence of ARF and hyperkalemia in elderly patients treated with ACEIs or ARBs after AMI hospitalization. However, a high rate of treatment discontinuation might prevent a higher rate of occurrence of these events. Long-term careful monitoring of severe adverse events and timely discontinuation of ACEIs or ARBs among elderly patients with advancing age and CKD after an AMI is warranted in clinical practice.

Long-Term Safety of Dapagliflozin in Older Patients with Type 2 Diabetes Mellitus: A Pooled Analysis of Phase IIb/III Studies

Objective

To evaluate the 104-week safety of dapagliflozin in older patients with type 2 diabetes mellitus.

Methods

Pooled analysis assessing general safety (nine phase III studies ≤104 weeks) and cardiovascular safety (21 phase IIb/III studies ≤208 weeks) by age (<65; ≥65; ≥75 years). Patients with type 2 diabetes mellitus (±background glucose-lowering therapy) received: dapagliflozin 10 mg (n = 2026) vs. placebo (n = 1956) (nine-study pool); or dapagliflozin (2.5–50 mg; n = 5936) vs. control (placebo/comparator) (n = 3403) (21-study pool).

Results

Adverse events (AEs) and discontinuations owing to AEs were more common in older vs. younger patients, and were more frequent with dapagliflozin than placebo (AEs: <65 years: 73.1 vs. 70.7 %; ≥65 years: 77.4 vs. 73.1 %; ≥75 years: 80.4 vs. 75.3 %, respectively; discontinuations: <65 years: 5.9 vs. 5.0 %; ≥65 years: 14.4 vs. 12.2 %; ≥75 years: 26.8 vs. 22.1 %, respectively); serious AE (SAE) frequency was similar (<65 years: 11.0 vs. 11.8 %; ≥65 years: 20.0 vs. 20.2 %; ≥75 years: 19.6 vs. 18.2 %, respectively). Hypoglycaemia frequency was similar across age groups and was higher with dapagliflozin than placebo (<65 years: 18.0 vs. 13.4 %; ≥65 years: 20.2 vs. 17.7 %; ≥75 years: 17.5 vs. 16.9 %, respectively); major episodes were rare. Urinary tract infection frequency was similar between treatment groups in older patients, with no increase vs. younger patients (<65 years: 8.8 vs. 5.5 %; ≥65 years: 8.1 vs. 7.6 %; ≥75 years: 8.2 vs. 9.1 %, respectively); urinary tract infection SAEs were rare. Genital infection AEs were more common with dapagliflozin, with no increase in older patients (<65 years: 8.2 vs. 1.0 %; ≥65 years: 6.6 vs. 0.9 %; ≥75 years: 7.2 vs. 0.0 %, respectively) and no SAEs. Volume reduction AEs were uncommon, with a higher frequency with dapagliflozin vs. placebo and in patients ≥75 years (<65 years: 1.7 vs. 1.2 %; ≥65 years: 2.3 vs. 1.7 %; ≥75 years: 3.1 vs. 2.6 %, respectively). Dapagliflozin did not increase the risk of fractures (<65 years: 1.1 vs. 1.1 %; ≥65 years: 1.1 vs. 2.7 %; ≥75 years: 1.0 vs. 2.6 %, respectively) or falls (<65 years: 0.7 vs. 0.7 %; ≥65 years: 0.6 vs. 2.1 %; ≥75 years: 0.0 vs. 1.3 %, respectively), regardless of age. AEs of renal function were more common with dapagliflozin than placebo and increased with age (<65 years: 3.5 vs. 2.3 %; ≥65 years: 14.0 vs. 7.9 %; ≥75 years: 29.9 vs. 20.8 %, respectively). Most were non-serious small transient increases in serum creatinine. Dapagliflozin did not increase cardiovascular risk regardless of age [hazard ratio (95 % confidence interval) vs. control: <65 years: 0.726 (0.473, 1.114); ≥65 years: 0.879 (0.565, 1.366); ≥75 years: 0.950 (0.345, 2.617), respectively].

Conclusion

Dapagliflozin treatment up to 104 weeks was well tolerated in older patients. Older dapagliflozin-treated patients had more renal AEs than placebo-treated patients; the majority of which were non-serious small transient changes in serum creatinine.

Electronic supplementary material

The online version of this article (doi:10.1007/s40266-016-0382-1) contains supplementary material, which is available to authorized users.

Transient Left Bundle Branch Block due to Severe Hyperkalemia

Hyperkalemia is a potentially life-threatening electrolyte imbalance that can lead to sudden death from cardiac arrhythmias and asystole. We present a case of transient left bundle branch block pattern on an electrocardiogram (ECG) secondary to hyperkalemia in a patient with history of end-stage renal disease. A 52-year-old man presented to the emergency room (ER) with chief complaints of weakness and lethargy after missing his regularly scheduled session of hemodialysis. A 12-lead ECG in the ER showed sinus tachycardia at 118 beats/min, wide QRS complexes, peaked T waves and left bundle branch block-like pattern. The initial basic metabolic panel revealed a serum potassium level of 8.8 mEq/L. Subsequently, the patient underwent emergent hemodialysis. Serum chemistry after hemodialysis showed improvement in serum potassium to 4.3 mEq/L. Repeat ECG performed after correcting potassium showed dissolution of left bundle branch block finding.

The effect of co-trimoxazole on serum potassium concentration: safety evaluation of a randomized controlled trial

AIMS

Co-trimoxazole maintains a well-established role in the treatment of Pneumocystis jirovecii and Toxoplasma gondii, as well as urinary tract infections. Observational studies report hyperkalaemia to be associated with co-trimoxazole, which may stem from an amiloride-like potassium-sparing effect. The current study investigated changes in serum potassium in patients without acute infections, and the influence of concomitant antikaliuretic drugs on this effect.

METHODS

A post hoc analysis was carried out of a randomized controlled trial in patients with interstitial lung disease who were assigned to placebo or 960 mg co-trimoxazole twice daily. Serum potassium and creatinine were measured at baseline, 6 weeks, and 6, 9 and 12 months. The primary outcome was the difference in mean serum potassium concentrations between co-trimoxazole and placebo at 6 weeks.

RESULTS

Mean serum potassium levels were similar at baseline: 4.24 (± 0.44) mmol l^-1 in the 87 co-trimoxazole group participants and 4.25 (± 0.39) mmol l^-1 in the 83 control participants. Co-trimoxazole significantly increased mean serum potassium levels at 6 weeks, with a difference between means compared with placebo of 0.21 mmol l^-1 [95% confidence interval (CI) 0.09, 0.34; P = 0.001). This significant increase in serum potassium was detectable even after exclusion of patients on antikaliuretic drugs, with a difference between means for co-trimoxazole compared with placebo of 0.23 mmol l^-1 (95% CI 0.09, 0.38; P = 0.002). There were 5/87 (5.7%) patients on co-trimoxazole whose serum potassium concentrations reached ≥5.5 mmol l^-1 during the study period.

CONCLUSIONS

Co-trimoxazole significantly increases serum potassium concentration, even in participants not using antikaliuretic drugs. While the magnitude of increase was often minor, a small proportion in our outpatient cohort developed hyperkalaemia of clinical importance.

Dialysate Potassium, Serum Potassium, Mortality, and Arrhythmia Events in Hemodialysis: Results From the Dialysis Outcomes and Practice Patterns Study (DOPPS)

BACKGROUND

Sudden death is a leading cause of death in patients on maintenance hemodialysis therapy. During hemodialysis sessions, the gradient between serum and dialysate levels results in rapid electrolyte shifts, which may contribute to arrhythmias and sudden death. Controversies exist about the optimal electrolyte concentration in the dialysate; specifically, it is unclear whether patient outcomes differ among those treated with a dialysate potassium concentration of 3 mEq/L compared to 2 mEq/L.

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

55,183 patients from 20 countries in the Dialysis Outcomes and Practice Patterns Study (DOPPS) phases 1 to 5 (1996-2015).

PREDICTOR

Dialysate potassium concentration at study entry.

OUTCOMES

Cox regression was used to estimate the association between dialysate potassium concentration and both all-cause mortality and an arrhythmia composite outcome (arrhythmia-related hospitalization or sudden death), adjusting for potential confounders.

RESULTS

During a median follow-up of 16.5 months, 24% of patients died and 7% had an arrhythmia composite outcome. No meaningful difference in clinical outcomes was observed for patients treated with a dialysate potassium concentration of 3 versus 2 mEq/L (adjusted HRs were 0.96 [95% CI, 0.91-1.01] for mortality and 0.98 [95% CI, 0.88-1.08] for arrhythmia composite). Results were similar across predialysis serum potassium levels. As in prior studies, higher serum potassium level was associated with adverse outcomes. However, dialysate potassium concentration had only minimal impact on serum potassium level measured predialysis (+0.09 [95% CI, 0.05-0.14] mEq/L serum potassium per 1 mEq/L greater dialysate potassium concentration).

LIMITATIONS

Data were not available for delivered (vs prescribed) dialysate potassium concentration and postdialysis serum potassium level; possible unmeasured confounding.

CONCLUSIONS

In combination, these results suggest that approaches other than altering dialysate potassium concentration (eg, education on dietary potassium sources and prescription of potassium-binding medications) may merit further attention to reduce risks associated with high serum potassium levels.

Community-acquired hyperkalemia in elderly patients: risk factors and clinical outcomes

BACKGROUND

Although the risk and related factors of hyperkalemia developed in the hospital are known in elderly, risk and related factors of community-acquired hyperkalemia (CAH) in this population are not well known. This study was performed to investigate the risk of CAH in elderly and evaluate the related factors and clinical outcomes. Study design, setting and participants, intervention: Patients (aged ≥65 years) with hyperkalemia were screened. Group 1 (young-old); 65-74 years/old, Group 2 (middle-old); 75-84 years/old, Group 3 (oldest-old); ≥85 years/old, and Group 4 (control group); ≥65 years/old (normal serum potassium levels). The relation between CAH and hospital expenses (HE), the number of comorbid diseases (NCD), and all-cause of mortality rates (MR) were evaluated. We also investigated whether drugs, sex, and NCD are risk factors for the development of CAH.

RESULTS

There was a positive correlation between serum potassium levels and length of hospital stay, MR, HE, and NCD (p < 0.001). Risk factors for CAH were the use of non-steroidal-anti inflammatory drugs (NSAIDs) (Odds Ratio [OR]: 2.679), spironolactone (OR: 2.530), and angiotensin converting enzyme inhibitors (ACEI) (OR: 2.242), angiotensin receptor blockers (ARB) (OR: 2.679), ≥2 comorbid diseases (OR: 2.221), female gender (OR: 2.112), and renal injury (OR: 5.55). CAH risk was found to be increased 30.03 times when any of ACEI, ARB, NSAIDs, or spironolactone is given to a patient with a renal injury.

CONCLUSION

Use of NSAIDs, ACEI, ARB, spironolactone and increased NCD are all independent risk factors for CAH in the elderly, especially in patients with kidney diseases.

Pharmacodynamics and pharmacokinetics of sodium zirconium cyclosilicate [ZS-9] in the treatment of hyperkalemia

INTRODUCTION

Hyperkalemia is a common electrolyte disorder that arises from dysfunctional homeostatic mechanisms or as a consequence of decreased renal function. Sodium zirconium cyclosilicate (ZS-9) is a potential new therapy for hyperkalemia in both acute and chronic settings.

AREAS COVERED

Here we discuss mechanisms of potassium homeostasis and preclinical and clinical studies that present pharmacokinetics/pharmacodynamics, efficacy and safety profiles of ZS-9.

EXPERT OPINION

ZS-9 has a unique mechanism of action consisting of thermodynamically favorable sequestration of potassium ions, enabling rapid trapping and removal of excess potassium. The potassium lowering action of ZS-9 is predictable and rapid, leading to significant reduction of serum potassium within 1 hour of administration by irreversibly eliminating excess potassium rather than acting via intracellular translocation. Its safety profile, including gastrointestinal events, has been generally similar to that of placebo, with the exception of infrequent but manageable events of peripheral edema and transient hypokalemia. ZS-9 has demonstrated potential for enabling renin-angiotensin-aldosterone system inhibitors in mid-term studies, with long-term studies ongoing.

Hyperkalemia constitutes a constraint for implementing renin-angiotensin-aldosterone inhibition: the widening gap between mandated treatment guidelines and the real-world clinical arena

Recent studies have reported a large gap between the forceful and assertive recommendations in the guidelines and real-world practice in the use of renin-angiotensin-aldosterone inhibitors (RAASi) therapies. A comprehensive, retrospective analysis of a large database of electronic medical records (>7 million patients) was undertaken to evaluate 3 pivotal concerns: (i) whether RAASi are being prescribed according to treatment guidelines, (ii) what happens to RAASi prescriptions after hyperkalemia events, and (iii) what the clinical outcomes are in patients whose RAASi are discontinued or who are prescribed at doses lower than the guidelines recommend. The results indicate that a substantial gap exists between guideline recommendations and real-world prescribing patterns for RAASi. Among patients with cardiorenal comorbidities for which RAASi are recommended by the guidelines, more than one-half were prescribed lower-than-recommended doses, and approximately 14% to 16% discontinued RAASi therapy. RAASi prescribing patterns may be altered by the development of hyperkalemia. Moderate-to-severe hyperkalemia events were followed by down-titration or discontinuation of RAASi therapy in nearly one-half of all patients on maximal dose and by discontinuation in nearly one-third of patients on submaximal dose. This analysis highlights the challenge behind RAASi prescribing decisions, balancing the risk of provoking hyperkalemia with the benefits to reducing cardiorenal morbidity and mortality. Patients who are known to derive the greatest benefit from these drugs (chronic kidney disease patients with concomitant diabetes mellitus or heart failure) are the same patients who are at highest risk of developing hyperkalemia. These observations constitute a "call to action" to develop newer treatment modalities to lower serum potassium and to achieve and sustain normokalemia long-term.

Effect of the SGLT2 Inhibitor Dapagliflozin on Potassium Levels in Patients with Type 2 Diabetes Mellitus: A Pooled Analysis

INTRODUCTION

Hyperkalemia risk is increased in diabetes, particularly in patients with renal impairment or those receiving angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs) or potassium-sparing diuretics. Conversely, other diuretics can increase hypokalemia risk. We assessed the effects of the sodium glucose co-transporter 2 (SGLT2) inhibitor dapagliflozin on serum potassium levels in a pooled analysis of clinical trials in patients with type 2 diabetes mellitus (T2DM).

METHODS

Fourteen randomized, placebo-controlled, double-blind T2DM studies were analyzed: pooled data from 13 studies of ≤24 weeks' duration (dapagliflozin 10 mg, N = 2360; placebo, N = 2295); and one 52-week moderate renal impairment study in patients with baseline eGFR ≥30 to <60 mL/min/1.73 m(2) (dapagliflozin 10 mg, N = 85; placebo, N = 84). Central laboratory serum potassium levels were determined at each study visit.

RESULTS

No clinically relevant mean changes from baseline in serum potassium ≤24 weeks were reported for dapagliflozin 10 mg [-0.05 mmol/L; 95% confidence interval (CI) -0.07, -0.03] versus placebo (-0.02 mmol/L; 95% CI -0.04, 0.00) in the pooled population or in the renal impairment study (-0.03 mmol/L; 95% CI -0.14, 0.08 vs. -0.02 mmol/L; 95% CI -0.13, 0.09, respectively). The incidence rate ratio for serum potassium ≥5.5 mmol/L over 24 weeks for dapagliflozin 10 mg versus placebo was 0.90 (95% CI 0.74, 1.10) in the pooled population; with no increased risk in patients receiving ARBs/ACE inhibitors, or potassium-sparing diuretics, or in those with moderate renal impairment. Slightly more patients receiving dapagliflozin 10 mg had serum potassium ≤3.5 mmol/L versus placebo (5.2% vs. 3.6%); however, no instances of serum potassium ≤2.5 mmol/L were reported.

CONCLUSION

Dapagliflozin is not associated with an increased risk of hyperkalemia or severe hypokalemia in patients with T2DM.

FUNDING

Bristol-Myers Squibb and AstraZeneca.

Aging-related impairment of urine-concentrating mechanisms correlates with dysregulation of adrenocortical angiotensin type 1 receptors in male Fischer rats

To investigate age-associated impairments in fluid homeostasis, 4-mo (young) and 32-mo (old) Fischer 344/BN male rats were studied before and after a dietary sodium load. Transferring young rats from a low-sodium (LS) to a high-sodium (HS) diet increased water intake and urine volume by 1.9- and 3.0-fold, respectively, while urine osmolality and plasma aldosterone decreased by 33 and 98%. Concomitantly, adrenocortical angiotensin type 1 receptor (AT1R) density decreased by 35%, and AT1bR mRNA decreased by 39%; no changes were observed in AT1aR mRNA. In contrast, the increase in water intake (1.4-fold) was lower in the old rats, and there was no effect of the HS diet on urine volume or urine osmolality. AT1R densities were 29% less in the old rats before transferring to the HS diet, and AT1R densities were not reduced as rapidly in response to a HS diet compared with the young animals. After 6 days on the HS diet, plasma potassium was lowered by 26% in the old rats, whereas no change was detected in the young rats. Furthermore, while plasma aldosterone was substantially decreased after 2 days on the HS diet in both young and old rats, plasma aldosterone was significantly lower in the old compared with the young animals after 2 wk on the LS diet. These findings suggest that aging attenuates the responsiveness of the adrenocortical AT1R to a sodium load through impaired regulation of AT1bR mRNA, and that this dysregulation contributes to the defects in water and electrolyte homeostasis observed in aging.

Carvedilol-induced hyperkalemia in a patient with chronic kidney disease

A 69-year-old male was admitted to the hospital with a chief complaint of abdominal pain, nausea, and vomiting. He had an extensive past medical history, including diabetes mellitus type 2 and chronic kidney disease stage III. Prior to admission, the patient was taking carvedilol 3.125 mg twice daily with no abnormality in his serum potassium. During hospitalization, his carvedilol was increased to 6.25 mg twice daily. The patient's serum potassium then rose from 4.8 to 6.7 mEq/L, with no improvement following administration of sodium polystyrene sulfonate. Nephrology concluded the carvedilol could be contributing to the hyperkalemia. The dose was decreased back to 3.125 mg twice daily, leading to the potassium normalizing to 4.4 mEq/L. The reported incidence of beta-blocker-induced hyperkalemia is less than 5%. A literature search revealed several cases of beta-blocker-induced hyperkalemia, but to the authors' knowledge, this is the first case describing carvedilol specifically. Utilization of the Naranjo probability scale indicated a possible probability that the carvediol was the cause.

Nutraceuticals for geriatrics

Geriatrics is a medical practice that addresses the complex needs of older patients and emphasizes maintaining functional independence even in the presence of chronic disease. Treatment of geriatric patients requires a different strategy and is very complex. Geriatric medicines aim to promote health by preventing and treating diseases and disabilities in older adults. Development of effective dietary interventions for promoting healthy aging is an active but challenging area of research because aging is associated with an increased risk of chronic disease, disability, and death. Aging populations are a global phenomenon. The most widespread conditions affecting older people are hypertension, congestive heart failure, dementia, osteoporosis, breathing problems, cataract, and diabetes to name a few. Decreased immunity is also partially responsible for the increased morbidity and mortality resulting from infectious agents in the elderly. Nutritional status is one of the chief variables that explains differences in both the incidence and pathology of infection. Elderly people are at increased risk for micronutrient deficiencies due to a variety of factors including social, physical, economic, and emotional obstacles to eating. Thus there is an urgent need to shift priorities to increase our attention on ways to prevent chronic illnesses associated with aging. Individually, people must put increased efforts into establishing healthy lifestyle practices, including consuming a more healthful diet. The present review thus focuses on the phytochemicals of nutraceutical importance for the geriatric population.

Relationship between seasonal weather changes, risk of dehydration, and incidence of severe bradyarrhythmias requiring urgent temporary transvenous cardiac pacing in an elderly population

There is little information on any seasonal variations or meteorological factors associated with symptomatic bradyarrhythmias requiring cardiac pacing. The aim of this single-center study was to investigate the seasonal distribution of the incidence of severe, life-threatening bradyarrhythmias requiring urgent temporary transvenous cardiac pacing in an elderly population. Consecutive patients who underwent urgent temporary transvenous cardiac pacing between 2007 and 2012 were enrolled. The baseline characteristics of the patients and some meteorological parameters, including the calculation the daily heat index (HI), were recorded. During the study period, 79 consecutive patients (mean age 82 ± 8 years, 41% male) underwent urgent temporary transvenous cardiac pacing, mainly for third-degree atrioventricular block (79%). The incidence of bradyarrhythmias was significantly higher in summer than in the other seasons (P < 0.001). Moreover, the highest incidence was observed in months with HI > 90 °F for >3 h per day for at least 10 days (P < 0.001). A direct correlation was found between the average monthly temperature and the monthly number of patients undergoing temporary cardiac pacing (r = 0.54, P < 0.001). Compared with other patients, those observed during the hottest months were significantly older and more frequently affected by chronic disabling neurological diseases (all P < 0.05). In addition, they more frequently showed biochemical indices of dehydration, renal function impairment and hyperkalemia (all P < 0.05). This study showed an increased incidence of severe bradyarrhythmias in an elderly population during the hottest months of the year. In these months, in subjects characterized by increased susceptibility to dehydration, the risk of developing bradyarrhythmias was increased significantly.

Extended release potassium salts overdose and endoscopic removal of a pharmacobezoar: A case report

BACKGROUND

Reported cases of potassium overdoses have shown that this condition could generate several morbidities, mainly related to cardiac dysrhythmias even with fatal outcomes in some cases. Potassium salts in extended release tablets could form pharmacobezoars if a large amount is ingested. In relation to the above, when the patient has a pharmacobezoar, clinical findings may be delayed and may persist. The techniques available for removal of a pharmacobezoar are whole bowel irrigation (WBI), endoscopy or in some surgery [1]. Endoscopy as a decontamination method has shown promising results.

CASE REPORT

A 42 year old woman, who intentionally ingested 100 tablets of extended release potassium chloride, 50 mg of clonazepam and an undisclosed amount of ethanol, presented with metabolic acidosis, hyperlactatemia and sinus tachycardia 2 h after ingestion. Gastric lavage and activated charcoal were applied initially, specific measures were not necessary. However, a transcutaneous pacemaker was placed. Because of her background, we considered a pharmacobezoar and an endoscopy were performed to remove 99 tablets of potassium that were isolated or forming concretions.

DISCUSSION

The readily available techniques to remove a pharmacobezoar are whole bowel irrigation (WBI) and endoscopy; nevertheless there is not a consensus about their relative merits. Our patient was treated by endoscopy because we found on the X-ray a conglomerate of radiopaque images suggesting a pharmacobezoar. In this case we did not have any adverse effect.

CONCLUSIONS

We consider that endoscopy could be an effective and safe method to remove a drug bezoar from the stomach in uncomplicated patients.

Hyperkalemia among hospitalized patients and association between duration of hyperkalemia and outcomes

INTRODUCTION

The aim of the study was to investigate predictors of mortality in patients hospitalized with hyperkalemia.

MATERIAL AND METHODS

Data among hospitalized patients with hyperkalemia (serum potassium ≥ 5.1 mEq/l) were collected. Patients with end-stage renal disease on dialysis were excluded.

RESULTS

Of 15,608 hospitalizations, 451 (2.9%) episodes of hyperkalemia occurred in 408 patients. In patients with hyperkalemia, chronic kidney disease, hypertension, diabetes, coronary artery disease and heart failure were common comorbidities. Acute kidney injury (AKI) and metabolic acidosis were common metabolic abnormalities, and 359 patients (88%) were on at least one drug associated with hyperkalemia. Mean duration to resolution of hyperkalemia was 12 ±9.9 h. Nonsteroidal anti-inflammatory drugs (HR = 1.59), highest potassium level (HR = 0.61), tissue necrosis (HR = 0.61), metabolic acidosis (HR = 0.77), and AKI (HR = 0.77) were significant independent determinants of duration prior to hyperkalemia resolution. Tissue necrosis (OR = 4.55), potassium supplementation (OR = 5.46), metabolic acidosis (OR = 4.84), use of calcium gluconate for treatment of hyperkalemia (OR = 4.62), AKI (OR = 3.89), and prolonged duration of hyperkalemia (OR = 1.06) were significant independent predictors of in-hospital mortality.

CONCLUSIONS

Tissue necrosis, potassium supplementation, metabolic acidosis, calcium gluconate for treatment of hyperkalemia, AKI and prolonged duration of hyperkalemia are independent predictors of in-hospital mortality.

The aging kidney revisited: a systematic review

As for the whole human body, the kidney undergoes age-related changes which translate in an inexorable and progressive decline in renal function. Renal aging is a multifactorial process where gender, race and genetic background and several key-mediators such as chronic inflammation, oxidative stress, the renin-angiotensin-aldosterone (RAAS) system, impairment in kidney repair capacities and background cardiovascular disease play a significant role. Features of the aging kidney include macroscopic and microscopic changes and important functional adaptations, none of which is pathognomonic of aging. The assessment of renal function in the framework of aging is problematic and the question whether renal aging should be considered as a physiological or pathological process remains a much debated issue. Although promising dietary and pharmacological approaches have been tested to retard aging processes or renal function decline in the elderly, proper lifestyle modifications, as those applicable to the general population, currently represent the most plausible approach to maintain kidney health.

Actual drug-drug interactions in elderly patients discharged from internal medicine clinic: a prospective observational study

PURPOSE

The aim of the study was to evaluate the incidence and type of actual drug-drug interactions (DDIs) that result in adverse drug reactions (ADRs) or diminished therapeutic effect in elderly patients within 30 days of discharge from an internal medicine clinic.

METHODS

A prospective observational study was conducted at the Internal Medicine Clinic of University Hospital Dubrava, Zagreb, Croatia, between October and December 2011. Patients aged ≥ 65 years discharged from the Internal Medicine Clinic during the study period with a prescription for two or more medications were eligible for inclusion in the study. A total of 222 patients were ultimately enrolled in the study. For each patient, potential DDIs were identified using Lexi-Interact software. The follow-up visit was scheduled approximately 30 days after discharge. Causality between DDIs and ADRs or diminished therapeutic effect of drugs was assessed by two independent clinicians.

RESULTS

Potential DDIs were identified in 190 (85.6 %) patients. Actual DDIs were detected in 21 (9.5 %) patients. In 19 patients, DDIs resulted in an ADR. Diminished therapeutic effect resulting from DDIs was detected in two patients. Angiotensin-converting enzyme inhibitors were the drug class most frequently associated with DDI-related ADRs.

CONCLUSIONS

A significant incidence of actual DDIs suggests that DDIs play an important role in patient safety. Drug therapy should be initiated if absolutely necessary, and the number of drugs used to treat elderly patients should be minimized to reduce the incidence of DDI-related adverse patient outcomes.

Acute kidney injury, sodium disorders, and hypercalcemia in the aging kidney: diagnostic and therapeutic management strategies in emergency medicine

This article summarizes the current literature regarding the structural and functional changes of the aging kidney and describes how these changes make the older patient more susceptible to acute kidney injury and fluid and electrolyte disorders. It discusses the clinical manifestations, evaluation, and management of hyponatremia and shows how the management of hypernatremia in geriatric patients involves addressing the underlying cause and safely correcting the hypernatremia. The current literature regarding evaluation and management of hypercalcemia in older patients is summarized. The management of severe hypercalcemia is discussed in detail. The evaluation and management of acute kidney injury is described.

Severe hyperkalemia requiring hospitalization: predictors of mortality

Introduction

Severe hyperkalemia, with potassium (K⁺) levels ≥ 6.5 mEq/L, is a potentially life-threatening electrolyte imbalance. For prompt and effective treatment, it is important to know its risk factors, clinical manifestations, and predictors of mortality.

Methods

An observational cohort study was performed at 2 medical centers. A total of 923 consecutive Korean patients were analyzed. All were 19 years of age or older and were hospitalized with severe hyperkalemia between August 2007 and July 2010; the diagnosis of severe hyperkalemia was made either at the time of admission to the hospital or during the period of hospitalization. Demographic and baseline clinical characteristics at the time of hyperkalemia diagnosis were assessed, and clinical outcomes such as in-hospital mortality were reviewed, using the institutions' electronic medical record systems.

Results

Chronic kidney disease (CKD) was the most common underlying medical condition, and the most common precipitating factor of hyperkalemia was metabolic acidosis. Emergent admission was indicated in 68.6% of patients, 36.7% had electrocardiogram findings typical of hyperkalemia, 24.5% had multi-organ failure (MOF) at the time of hyperkalemia diagnosis, and 20.3% were diagnosed with severe hyperkalemia at the time of cardiac arrest. The in-hospital mortality rate was 30.7%; the rate was strongly correlated with the difference between serum K⁺ levels at admission and at their highest point, and with severe medical conditions such as malignancy, infection, and bleeding. Furthermore, a higher in-hospital mortality rate was significantly associated with the presence of cardiac arrest and/or MOF at the time of diagnosis, emergent admission, and intensive care unit treatment during hospitalization. More importantly, acute kidney injury (AKI) in patients with normal baseline renal function was a strong predictor of mortality, compared with AKI superimposed on CKD.

Conclusions

Severe hyperkalemia occurs in various medical conditions; the precipitating factors are similarly diverse. The mortality rate is especially high in patients with severe underlying disease, coexisting medical conditions, and those with normal baseline renal function.

Adverse drug reactions caused by drug-drug interactions in elderly outpatients: a prospective cohort study

PURPOSE

Although the prevalence of drug-drug interactions (DDIs) in elderly outpatients is high, many potential DDIs do not have any actual clinical effect, and data on the occurrence of DDI-related adverse drug reactions (ADRs) in elderly outpatients are scarce. This study aimed to determine the incidence and characteristics of DDI-related ADRs among elderly outpatients as well as the factors associated with these reactions.

METHODS

A prospective cohort study was conducted between 1 November 2010 and 31 November 2011 in the primary public health system of the Ourinhos micro-region, Brazil. Patients aged ≥60 years with at least one potential DDI were eligible for inclusion. Causality, severity, and preventability of the DDI-related ADRs were assessed independently by four clinicians using validated methods; data were analysed using descriptive analysis and multiple logistic regression.

RESULTS

A total of 433 patients completed the study. The incidence of DDI-related ADRs was 6 % (n = 30). Warfarin was the most commonly involved drug (37 % cases), followed by acetylsalicylic acid (17 %), digoxin (17 %), and spironolactone (17 %). Gastrointestinal bleeding occurred in 37 % of the DDI-related ADR cases, followed by hyperkalemia (17 %) and myopathy (13 %). The multiple logistic regression showed that age ≥80 years [odds ratio (OR) 4.4; 95 % confidence interval (CI) 3.0-6.1, p < 0.01], a Charlson comorbidity index ≥4 (OR 1.3; 95 % CI 1.1-1.8, p < 0.01), consumption of five or more drugs (OR 2.7; 95 % CI 1.9-3.1, p < 0.01), and the use of warfarin (OR 1.7; 95 % CI1.1-1.9, p < 0.01) were associated with the occurrence of DDI-related ADRs. With regard to severity, approximately 37 % of the DDI-related ADRs detected in our cohort necessitated hospital admission. All DDI-related ADRs could have been avoided (87 % were ameliorable and 13 % were preventable). The incidence of ADRs not related to DDIs was 10 % (n = 44).

CONCLUSIONS

The incidence of DDI-related ADRs in elderly outpatients is high; most events presented important clinical consequences and were preventable or ameliorable.

Mild hyperkalemia and low eGFR a tedious recipe for cardiac disaster in the elderly: an unusual reversible cause of syncope and heart block

Hyperkalemia affects the myocardial tissue producing electrocardiographic abnormalities, such as prolongation of the P-R interval, tall peaked T waves, a reduction in the amplitude and an increase in the duration of P wave, and atrial and ventricular arrhythmias, including variable degree heart blocks. Elderly patients are particularly predisposed to developing hyperkalemia and the associated abnormalities due to an age-related reduction in glomerular filtration rate and pre-existing medical problems. Therefore, the impact of aging on potassium homeostasis must be taken into consideration, and preventive measures, such as early recognition of possible hyperkalemia in the geriatric population treated with certain medications or supplements must be investigated. The threshold for cardiac arrhythmias in the elderly can be lower than the general population. We report 3 unusual cases of mild hyperkalemia in elderly patients presenting with hypotension, syncope and variable degree heart blocks which resolved spontaneously with the correction of hyperkalemia.