Onset time of hyperkalaemia after angiotensin receptor blocker initiation: when should we start serum potassium monitoring?

Exploring Hyperkalemia Risk in Frail Older Patients Using RAAS Inhibitors

PURPOSE

Renin-angiotensin-aldosterone system inhibitors (RAASi) are widely used in treatment of cardiovascular and renal disease. While effective, they pose a risk of hyperkalemia. In the general population, risk factors for hyperkalemia include chronic kidney disease, congestive heart failure, and use of medication affecting potassium balance. These risk factors are prevalent in frail older patients. Therefore, this study aims to explore the prevalence and risk factors for hyperkalemia associated with RAASi use in this vulnerable population.

PATIENTS AND METHODS

This single-center, cross-sectional study included RAASi users aged ≥ 70 years who presented at the emergency department. Clinical Frailty Scale (CFS) according to Rockwood was calculated retrospectively from information in clinical files. All patients with CFS ≥ 5 were considered frail. Hyperkalemia was defined as serum potassium ≥ 5.5 mmol/L at time of presentation at the emergency department. Potential risk factors for hyperkalemia in older patients were identified using logistic regression models.

RESULTS

Of the 2023 participants, 86 (4.3%) were hyperkalemic, with no significant difference between frail and non-frail patients (4.7% versus 3.3%, p-value 0.157). Hyperkalemic patients were slightly younger than non-hyperkalemic patients (median age 83 versus 84 years, p-value 0.023), and females were slightly overrepresented in both groups (52.6% and 53.5%, p = 0.867). Risk factors associated with hyperkalemia in older RAASi users included younger age (odds ratio (OR) 0.95, 95% confidence intervals (CI) 0.92-0.99, p = 0.010), diabetes mellitus (OR 1.67, 95% CI 1.05-2.65, p = 0.030), moderate to severe kidney failure (OR 9.87, 95% CI 6.01-16.21, p < 0.001), and use of potassium-binding agents (OR 14.62, 95% CI 1.56-137.40, p = 0.019) and potassium-sparing diuretics (OR 2.66, 95% CI 1.57-4.50, p < 0.001).

CONCLUSIONS

Contrary to expectations, this study found no association between frailty and hyperkalemia in older RAASi users visiting the emergency department. These results suggest that frail older patients without additional risk factors can be treated with RAASi when indicated, similar to the general population. The main risk factors for hyperkalemia in this population remain consistent with those in the general population, emphasizing the importance of monitoring kidney function and medication use.

Effects of angiotensin II receptor blockers on serum potassium level and hyperkalemia risk: retrospective single-centre analysis

OBJECTIVE

To examine the effect of angiotensin II receptor blocker (ARB) treatment on serum potassium level and hyperkalaemia risk in a clinical setting with inpatients and outpatients using calcium channel blockers (CCBs) as a reference standard.

METHODS

The increased risk of hyperkalaemia associated with ARB treatment is known, however only a few studies have used an active comparator to examine this risk. In this retrospective study at a 320-bed general hospital in Japan, the hospital information system was used to identify patients with at least one prescription for an ARB (819 patients) or a CCB (1015 patients) who were naive to these drugs before study initiation. Serum potassium levels before and after ARB treatment were compared. Additionally, the unadjusted and adjusted hazard ratios for the risk of hyperkalaemia in the ARB and CCB users were estimated.

RESULTS

The serum potassium level was higher in patients receiving ARB treatment (0.05 mEq/L, p=0.02) compared with those on CCB treatment. However, there was no significant association between ARB use and hyperkalaemia (adjusted HR 0.91, 95% CI 0.42 to 1.99, p=0.82).

CONCLUSION

The increase in serum potassium level after ARB initiation makes it necessary to monitor serum potassium levels continuously during ARB treatment; however, the risk of hyperkalaemia appeared to be similar for ARB and CCB treatments.

Adverse Events After Initiating Angiotensin-Converting Enzyme Inhibitor/Angiotensin II Receptor Blocker Therapy in Individuals with Heart Failure and Multimorbidity

BACKGROUND

Current clinical practice guidelines recommend routine kidney function and serum potassium testing within 30 days of initiating angiotensin-converting enzyme inhibitor (ACEI) or angiotensin II receptor blocker (ARB) therapy. However, evidence is lacking on whether routine follow-up testing reduces therapy-related adverse events in adults with heart failure and if multimorbidity influences the association between laboratory testing and these adverse events.

METHODS

We conducted a retrospective cohort study among adults with heart failure from 4 US integrated health care delivery systems. Multimorbidity was defined using counts of chronic conditions. Patients with outpatient serum creatinine and potassium tests in the 30 days after starting ACEI or ARB therapy were matched 1:1 to patients without follow-up tests. We evaluated the association of follow-up testing with 30-day all-cause mortality and hospitalization with acute kidney injury or hyperkalemia using Cox regression.

RESULTS

We identified 3629 matched adults with heart failure initiating ACEI or ARB therapy between January 1, 2005, and December 31, 2012. Follow-up testing was not significantly associated with 30-day all-cause mortality (adjusted hazard ratio [aHR] 0.45, 95% confidence interval [CI] 0.14; 1.39) and hospitalization with hyperkalemia (aHR 0.73, 95% CI, 0.33; 1.61). However, follow-up testing was significantly associated with hospitalization with acute kidney injury (aHR, 1.40, 95% CI, 1.01; 1.94). Interaction between multimorbidity burden and follow-up testing was not statistically significant in any of the outcome models examined.

CONCLUSIONS

Routine laboratory monitoring after ACEI or ARB therapy initiation was not associated with risk of 30-day all-cause mortality or hospitalization with hyperkalemia across the spectrum of multimorbidity burden in a cohort of patients with heart failure.

Onset of Hyperkalemia following the Administration of Angiotensin-Converting Enzyme Inhibitor or Angiotensin II Receptor Blocker

Introduction

In spite of the established importance of detecting angiotensin-converting enzyme inhibitor (ACEI) or angiotensin II receptor blocker- (ARB-) induced hyperkalemia, there have not been many studies on the time of its occurrence.

Methods

We retrospectively analyzed electronic medical records to determine the onset time and incidence rate of hyperkalemia (serum potassium > 5.5 mEq/L or 6.0 mEq/L) among hospitalized patients newly started on a 15-day ACEI or ARB therapy.

Results

Among 3101 hospitalized patients, hyperkalemia incidence was 0.5%–0.9% and 0.8%–2.1% in the ACEI and ARB groups, respectively. However, it was not significantly different among different ARB types. Hyperkalemia's onset was distributed throughout 15 days, without any trend. Hyperkalemia incidence was 7.3 and 35.1 times higher at 5.5 mEq/L (hazard ratio (HR) = 7.31, 95%confidence interval (CI) = 4.19–12.76, p < 0.001) and 6.0 mEq/L (HR = 35.11, 95%CI = 8.25–149.52, p < 0.001), respectively, than the baseline creatinine level. Hyperkalemia incidence in patients with chronic renal failure was 5.7 and 9.2 times higher at 5.5 mEq/L (HR = 5.72, 95%CI = 3.24–10.12, p < 0.001) and 6.0 mEq/L (HR = 9.16, 95%CI = 4.02–20.88, p < 0.001), respectively.

Conclusions

It is unlikely that it is necessary to monitor hyperkalemia immediately after administration of ACEI or ARB. However, when prescribed for patients with abnormal kidney function, clinicians should always consider the possibility of developing hyperkalemia.

Kidney Function and Potassium Monitoring After Initiation of Renin-Angiotensin-Aldosterone System Blockade Therapy and Outcomes in 2 North American Populations

BACKGROUND

Clinical practice guidelines recommend routine kidney function and serum potassium testing within 30 days of initiating ACE (angiotensin-converting enzyme) inhibitor or angiotensin II receptor blocker therapy. However, evidence is lacking about whether follow-up testing reduces therapy-related adverse outcomes.

METHODS AND RESULTS

We conducted 2 population-based retrospective cohort studies in Kaiser Permanente Northern California and Ontario, Canada. Patients with outpatient serum creatinine and potassium tests in the 30 days after starting ACE inhibitor or angiotensin II receptor blocker therapy were matched 1:1 to patients without follow-up tests. We evaluated the association of follow-up testing with 30-day all-cause mortality and hospitalization with acute kidney injury or hyperkalemia using Cox regression. We also developed and externally validated a risk score to identify patients at risk of having abnormally high serum creatinine and potassium values in follow-up. We identified 75 251 matched pairs initiating ACE inhibitor or angiotensin II receptor blocker therapy between January 1, 2007, and December 31, 2017, in Kaiser Permanente Northern California. Follow-up testing was not significantly associated with 30-day all-cause mortality in Kaiser Permanente Northern California (hazard ratio, 0.75 [95% CI, 0.54-1.06]) and was associated with higher mortality in 84 905 matched pairs in Ontario (hazard ratio, 1.32 [95% CI, 1.07-1.62]). In Kaiser Permanente Northern California, follow-up testing was significantly associated with higher rates of hospitalization with acute kidney injury (hazard ratio, 1.66 [95% CI, 1.10-2.22]) and hyperkalemia (hazard ratio, 3.36 [95% CI, 1.08-10.41]), as was observed in Ontario. The risk score for abnormal potassium provided good discrimination (area under the curve [AUC], 0.75) and excellent calibration of predicted risks, while the risk score for abnormal serum creatinine provided moderate discrimination (AUC, 0.62) but excellent calibration.

CONCLUSIONS

Routine laboratory monitoring after ACE inhibitor or angiotensin II receptor blocker initiation was not associated with a lower risk of 30-day mortality. We identified patient subgroups in which targeted testing may be effective in identifying therapy-related changes in serum potassium or kidney function.

Associations between serum potassium and adverse clinical outcomes: A systematic literature review

BACKGROUND AND OBJECTIVES

Despite the growing body of evidence characterising the association between serum potassium levels and adverse clinical outcomes, a contemporary summary of available evidence is currently lacking. The objective of this study, therefore, was to undertake a systematic literature review to identify all relevant evidence assessing risk factors associated with the incidence of hyperkalaemia (HK) and also quantifying the effect of serum potassium levels on risk of adverse clinical outcomes.

METHODS

PubMed (Medline and Medline In-Process), Embase and the Cochrane Library were searched for studies published between January 2002 and November 2018. Search inclusion criteria included studies describing either the incidence of HK events and any associated risk factors, or associations between HK or serum potassium concentration and adverse clinical outcomes including mortality, hospitalisation, major adverse cardiac events (MACE) and renin-angiotensin-aldosterone system inhibitors (RAASi) discontinuation in adult patients with chronic kidney disease (CKD), heart failure (HF), type 2 diabetes (T2DM) or hypertension.

RESULTS

The search identified 1,897 publications. From these, a total of 123 studies met the inclusion criteria and were included in the review. The most commonly identified risk factors associated with HK events were the presence of CKD or renal impairment, T2DM, HF, hypertension, RAASi use and mineralocorticoid receptor antagonist use. Potassium levels both above and below the normal range were consistently associated with adverse clinical outcomes, with relative and absolute risks of outcomes increasing with severity of hyper- or hypokalaemia. These associations were consistently reported across a broad range of patient population types and study types.

CONCLUSION

The current body of published evidence is compelling in its confirmation of the associations between serum potassium levels and adverse clinical outcomes. This review further highlights the importance of avoiding both hyper- and hypokalaemia, in order to reduce risk of mortality, hospitalisation, MACE and RAASi discontinuation or down-titration.

Structure and Content of Drug Monitoring Advices Included in Discharge Letters at Interfaces of Care: Exploratory Analysis Preceding Database Development

BACKGROUND

Inadequate drug monitoring of drug therapy after hospital discharge facilitates adverse drug events and preventable hospital readmissions.

OBJECTIVE

This study aimed to analyze the structure and content of drug monitoring advices of a representative sample of discharge letters as a basis for future electronic information systems.

METHODS

On 2 days in November 2016, all discharge letters of 3 departments of a university hospital were extracted from the hospital information system. The frequency, content, and structure of drug monitoring advices in discharge letters were investigated and compared with the theoretical monitoring requirements expressed in the corresponding summaries of product characteristics (SmPC). The quality of the drug monitoring advices in the discharge letters was rated with the domains of an adapted systematic instructions for monitoring (SIM) score.

RESULTS

In total, 154 discharge letters were analyzed containing 1180 brands (240 active pharmaceutical substances), of which 50.42% (595/1180) could theoretically be amended with a monitoring advice according to the SmPC. In reality, 40 discharge letters (26.0%, 40/154) contained a total of 66 monitoring advices for 57 brands (4.83%, 57/1180), comprising 18 different monitoring parameters. Drug monitoring advices only addressed mean 1.9 (SD 0.8) of the 7 domains of the SIM score and frequently did not address reasons for monitoring (86%, 57/66), the timing of monitoring, that is, the start (76%, 50/66), the frequency (94%, 63/66), the stop (95%, 63/66), and how to react (83%, 55/66).

CONCLUSIONS

Drug monitoring advices were mostly absent in discharge letters and a gold standard for appropriate drug monitoring advices was lacking. Hence, more effort should be put in the development of tools that facilitate easy presentation of clinically meaningful drug monitoring advices at the point of care.

Renal function monitoring in heart failure - what is the optimal frequency? A narrative review

The second most common cause of hospitalization due to adverse drug reactions in the UK is renal dysfunction due to diuretics, particularly in patients with heart failure, where diuretic therapy is a mainstay of treatment regimens. Therefore, the optimal frequency for monitoring renal function in these patients is an important consideration for preventing renal failure and hospitalization. This review looks at the current evidence for optimal monitoring practices of renal function in patients with heart failure according to national and international guidelines on the management of heart failure (AHA/NICE/ESC/SIGN). Current guidance of renal function monitoring is in large part based on expert opinion, with a lack of clinical studies that have specifically evaluated the optimal frequency of renal function monitoring in patients with heart failure. Furthermore, there is variability between guidelines, and recommendations are typically nonspecific. Safer prescribing of diuretics in combination with other antiheart failure treatments requires better evidence for frequency of renal function monitoring. We suggest developing more personalized monitoring rather than from the current medication-based guidance. Such flexible clinical guidelines could be implemented using intelligent clinical decision support systems. Personalized renal function monitoring would be more effective in preventing renal decline, rather than reacting to it.

Pilot Algorithm Designed to Help Early Detection of HMG-CoA Reductase Inhibitor-Induced Hepatotoxicity

Objectives

To enable early detection of adverse drug reactions (ADRs) in patients using HMG-CoA reductase inhibitors (statins), we developed an algorithm that automatically detects liver injury caused by statins from Electronic Medical Record (EMR) data. We verified the performance of our algorithm through manual ADR assessment and a direct chart review.

Methods

The subjects in this study were patients who had been prescribed a statin for the first time among outpatients in Seoul St. Mary's Hospital in Korea between January 2009 and December 2012. We extracted basic information about the patients, including laboratory information, underlying disease, diagnosis information, prescription information, and concomitant drugs. We developed an automatic ADR detection algorithm by using EMR data. We validated the results of the algorithm through a chart review.

Results

We developed the algorithm to assess ADR occurrences based on alanine transaminase (ALT) and alkaline phosphatase (ALP) levels. According to the proposed algorithm, any of these result options could be attained: ADR-free, little association, strong association, and weak association or indeterminable. The results of the ADR assessments obtained using the proposed algorithm showed that the data of 126 patients (1.4% of all 9,241 patients) included suspicious figures, thus indicating the possibility of an ADR. In the EMR chart review for verifying the algorithm, ADRs of 33 patients were not associated with statin use; therefore, the ADR occurrence rate was found to be 1.0% (93/9,241). Therefore, the positive predictive value was calculated to be 73.8% (93/126; 95% confidence interval, 69.2%–77.6%). No differences were observed between statin types (p = 0.472).

Conclusions

For early detection of statin-induced liver injury, we developed an automatic ADR assessment algorithm. We expect that algorithms that are more reliable can be developed if we conduct supplement clinical studies with a focus on adverse drug effects.

The relationship between the failure to eradicate Helicobacter pylori and previous antibiotics use

BACKGROUND

The previous use of antibiotics is known to correlate positively with antibiotic resistance; whether this is also the case in the eradication of Helicobacter pylori infection is unclear.

AIM

To investigate the relationship between the previous use of antibiotics and the failure of eradication therapy in H. pylori infection.

METHODS

The relationship between the clinical parameters and the failure of H. pylori eradication was analyzed in patients administered standard triple therapy and then assessed for the eradication of H. pylori based on a C13-urea breath test.

RESULTS

In a multivariate analysis, failure rates increased significantly in patients with a history of clarithromycin (odds ratio [OR], 4.445) or other macrolides (OR, 2.407) use, who were female (OR, 1.339), or who were older than 60 years of age (OR, 1.326). The eradication failure rate in patients with a history of macrolides use for >2 weeks was significantly higher than if the duration of use was <2 weeks (44.8% vs. 29.3%, p=0.047).

CONCLUSIONS

A patient's history of macrolides is a useful predictor of the likelihood of standard triple therapy failure in H. pylori eradication. The alternatives such as a bismuth-based quadruple or a levofloxacin-containing therapy should be considered in patients treated with macrolides for >2 weeks.

Potential New Agents for the Management of Hyperkalemia

Hyperkalemia is a common electrolyte disturbance with multiple potential etiologies. It is usually observed in the setting of reduced renal function. Mild to moderate hyperkalemia is usually asymptomatic, but is associated with poor prognosis. When severe, hyperkalemia may cause serious acute cardiac arrhythmias and conduction abnormalities, and may result in sudden death. The rising prevalence of conditions associated with hyperkalemia (heart failure, chronic kidney disease, and diabetes) and broad use of renin-angiotensin-aldosterone system (RAAS) inhibitors and mineralocorticoid receptor antagonists (MRAs), which improve patient outcomes but increase the risk of hyperkalemia, have led to a significant rise in hyperkalemia-related hospitalizations and deaths. Current non-invasive therapies for hyperkalemia either do not remove excess potassium or have poor efficacy and tolerability. There is a clear need for safer, more effective potassium-lowering therapies suitable for both acute and chronic settings. Patiromer sorbitex calcium and sodium zirconium cyclosilicate (ZS-9) are two new potassium-lowering compounds currently in development. Although they have not yet been approved by the US FDA, both have demonstrated efficacy and safety in recent trials. Patiromer sorbitex calcium is a polymer resin and sorbitol complex that binds potassium in exchange for calcium; ZS-9, a non-absorbed, highly selective inorganic cation exchanger, traps potassium in exchange for sodium and hydrogen. This review discusses the merits of both novel drugs and how they may help optimize the future management of patients with hyperkalemia.

Amiloride lowers blood pressure and attenuates urine plasminogen activation in patients with treatment-resistant hypertension

In conditions with albuminuria, plasminogen is aberrantly filtered across the glomerular barrier and activated along the tubular system to plasmin. In the collecting duct, plasmin activates epithelial sodium channels (ENaC) proteolytically. Hyperactivity of ENaC could link microalbuminuria/proteinuria to resistant hypertension. Amiloride, an ENaC inhibitor, inhibits urokinase-type plasminogen activator. We hypothesized that amiloride (1) reduces blood pressure (BP); (2) attenuates plasminogen-to-plasmin activation; and (3) inhibits urine urokinase-type plasminogen activator in patients with resistant hypertension and type 2 diabetes mellitus (T2DM).In an open-label, non-randomized, 8-week intervention study, a cohort (n = 80) of patients with resistant hypertension and T2DM were included. Amiloride (5 mg/d) was added to previous triple antihypertensive treatment (including a diuretic and an inhibitor of the renin-angiotensin-aldosterone system) and increased to 10 mg if BP control was not achieved at 4 weeks. Complete dataset for urine analysis was available in 60 patients. Systolic and diastolic BP measured by ambulatory BP monitoring and office monitoring were significantly reduced. Average daytime BP was reduced by 6.3/3.0 mm Hg. Seven of 80 cases (9%) discontinued amiloride due to hyperkalemia >5.5 mol/L, the most frequent adverse event. Urinary plasmin(ogen) and albumin excretions were significantly reduced after amiloride treatment (P < .0001). Urokinase activity was detectable in macroalbuminuric urine, with a tendency toward reduction in activity after amiloride treatment. Amiloride lowers BP, urine plasminogen excretion and activation, and albumin/creatinine ratio, and is a relevant add-on medication for the treatment of resistant hypertension in patients with T2DM and microalbuminuria.

Effect of potassium present in stratum corneum during non-invasive measurement of potassium in human subjects using reverse iontophoresis

PURPOSE

Reverse iontophoresis (RI) is one of the potential techniques used to monitor the concentration of various analytes in body fluids non-invasively. Transdermal extraction of potassium is investigated using RI. In the present work, the effect of potassium on stratum corneum (SC) during RI, feasibility of RI for continuous monitoring of potassium, and use of potassium as internal standard in RI, are investigated.

METHODS

Tape stripping experiment is carried out to find potassium concentration in SC. RI is carried out continuously for 180 min without passive diffusion and after passive diffusion for 60 min. Skin impedance measurements are done at 20 Hz and 20 kHz.

RESULTS

Potassium is found to be in the range 300-650 nmol/cm(2) on SC by tape stripping experiment. Correlation coefficient between blood potassium and extracted potassium through RI after passive diffusion (R(2) = 0.5870) is more than without passive diffusion (R(2) = 0.5117). The skin impedance measurement shows that RI has more effect on SC than superficial layer of SC during RI.

CONCLUSION

The present investigations conclude that it is possible to monitor potassium continuously through RI and using potassium as internal standard in RI.

A Review of the Benefits of Satureja Species on Metabolic Syndrome and Their Possible Mechanisms of Action

Metabolic syndrome, also known as insulin resistance disorder, is the simultaneous manifestation of multiple metabolic disorders in an individual. The present-day complementary and alternative therapies suggest several medicinal herbs that may have the potential to improve one or multiple complications of metabolic syndrome. All of them have their own limitations in efficacy and unwanted effects. Therefore, we reviewed species of Satureja as widespread medicinal herbs and potentially good remedies for metabolic syndrome. We reviewed literature found in PubMed and the ISI Web of Knowledge with the key word Satureja in the title. The influence of any species of Satureja on any disease or syndrome, enzymatic, metabolic, or physiological pathways, in human, animals, or in vitro conditions related to any characteristics of metabolic syndrome were considered. The main outcomes of treatment with Satureja species were categorized, and the possible mechanisms of action are discussed in this article.

The Model for End-stage Liver Disease score is potentially a useful predictor of hyperkalemia occurrence among hospitalized angiotensin receptor blocker users

WHAT IS KNOWN AND OBJECTIVE

Angiotensin receptor blockers (ARBs) are medications commonly used for treating conditions such as hypertension. However, ARBs are frequently associated with hyperkalemia, a potentially critical adverse event, in high-risk patients. Although both the liver and the kidney are major elimination routes of ARBs, the relationship between hepatorenal function and ARB-related hyperkalemia has not yet been investigated. The purpose of this study was to evaluate the risk of hyperkalemia, in terms of various hepatorenal functions, for hospitalized patients newly initiated on ARB treatment.

METHODS

We evaluated ARB-related hyperkalemia in a cohort of 5530 hospitalized patients, who had not previously used ARBs, between 12 April 2004 and 31 May 2012. Hepatorenal function was assessed by the Model for End-stage Liver Disease (MELD) score. Hyperkalemia risk was assessed by hepatorenal function, risks were categorized into the four MELD scoring groups, and the groups were compared with one another.

RESULTS AND DISCUSSION

The MELD score was significantly different between the hyperkalemic and non-hyperkalemic groups (independent t-test, P < 0.001). The MELD score 10-14, 15-19 and ≥ 20 groups showed higher risks of hyperkalemia than the lowest MELD score group {log-rank test, P < 0.001; multiple Cox proportional hazard model, hazard ratios 1.478 (P = 0.003), 2.285 (P < 0.001) and 3.024 (P < 0.001), respectively}.

WHAT IS NEW AND CONCLUSION

The MELD score showed a stronger predictive performance for hyperkalemia than either serum creatinine or estimated glomerular filtration rate alone. Furthermore, the MELD score showed good predictive performance for ARB-related hyperkalemia among hospitalized patients. The clinical implications and reasons for these findings merit future investigation.