Diabetes and drug-associated hyperkalemia: effect of potassium monitoring

Impact of ACEIs and ARBs-related adverse drug reaction on patients' clinical outcomes: a cohort study in UK primary care

BACKGROUND

Adverse drug reaction (ADR) related to angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) may negatively affect patients' treatment outcomes.

AIM

To investigate the impact of ACEIs/ARBs-related ADR consultation on cardiovascular disease (CVD) events and all-cause mortality.

DESIGN AND SETTING

Propensity score-matched cohort study of ACEIs/ARBs between 2004 and 2019 using UK IQVIA medical research data.

METHOD

ADR consultations were identified using standardised designated codes. Propensity scores were calculated based on comorbidities, concomitant medications, frailty, and polypharmacy. Cox's proportional hazard regression model was used to compare the outcomes between patients in ADR and non-ADR groups. In the secondary analysis, treatment- pattern changes following the ADR were examined and the subsequent outcomes were compared.

RESULTS

Among 1 471 906 eligible users of ACEIs/ARBs, 13 652 (0.93%) patients had ACEIs/ARBs- related ADR consultation in primary care. Patients with ACEIs/ARBs-related ADR consultation had an increased risk of subsequent CVD events and all- cause mortality in both primary prevention (CVD events: adjusted hazard ratio [aHR] 1.22, 95% confidence interval [CI] = 1.05 to 1.43; all-cause mortality: aHR 1.14, 95% CI = 1.01 to 1.27) and secondary prevention cohorts (CVD events: aHR 1.13, 95% CI = 1.05 to 1.21; all-cause mortality: aHR 1.15, 95% CI = 1.09 to 1.21). Half (50.19%) of patients with ADR continued to use ACEIs/ARBs, and these patients had a reduced risk of mortality (aHR 0.88, 95% CI = 0.82 to 0.95) compared with those who discontinued using ACEIs/ARBs.

CONCLUSION

This study provides information on the burden of ADR on patients and the health system. The findings call for additional monitoring and treatment strategies for patients affected by ADR to mitigate the risks of adverse clinical outcomes.

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.

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.

Noninvasive Screening Tool for Hyperkalemia Using a Single-Lead Electrocardiogram and Deep Learning: Development and Usability Study

Background

Hyperkalemia monitoring is very important in patients with chronic kidney disease (CKD) in emergency medicine. Currently, blood testing is regarded as the standard way to diagnose hyperkalemia (ie, using serum potassium levels). Therefore, an alternative and noninvasive method is required for real-time monitoring of hyperkalemia in the emergency medicine department.

Objective

This study aimed to propose a novel method for noninvasive screening of hyperkalemia using a single-lead electrocardiogram (ECG) based on a deep learning model.

Methods

For this study, 2958 patients with hyperkalemia events from July 2009 to June 2019 were enrolled at 1 regional emergency center, of which 1790 were diagnosed with chronic renal failure before hyperkalemic events. Patients who did not have biochemical electrolyte tests corresponding to the original 12-lead ECG signal were excluded. We used data from 855 patients (555 patients with CKD, and 300 patients without CKD). The 12-lead ECG signal was collected at the time of the hyperkalemic event, prior to the event, and after the event for each patient. All 12-lead ECG signals were matched with an electrolyte test within 2 hours of each ECG to form a data set. We then analyzed the ECG signals with a duration of 2 seconds and a segment composed of 1400 samples. The data set was randomly divided into the training set, validation set, and test set according to the ratio of 6:2:2 percent. The proposed noninvasive screening tool used a deep learning model that can express the complex and cyclic rhythm of cardiac activity. The deep learning model consists of convolutional and pooling layers for noninvasive screening of the serum potassium level from an ECG signal. To extract an optimal single-lead ECG, we evaluated the performances of the proposed deep learning model for each lead including lead I, II, and V1-V6.

Results

The proposed noninvasive screening tool using a single-lead ECG shows high performances with F1 scores of 100%, 96%, and 95% for the training set, validation set, and test set, respectively. The lead II signal was shown to have the highest performance among the ECG leads.

Conclusions

We developed a novel method for noninvasive screening of hyperkalemia using a single-lead ECG signal, and it can be used as a helpful tool in emergency medicine.

Changing the medication documentation process for discharge: impact on clinical routine and documentation quality-a process analysis

OBJECTIVES

In 2017, an in-house best-practice process for medication documentation was developed and implemented to meet the new German legal requirements concerning the management of patient discharge from the hospital. Because this law regulates the common steps of good discharge practices (eg, specification of discharge mediation documentation), we used its implementation to assess the impact of such a measure on the quality of medication documentation and related workflows in clinical routine.

METHODS

By observing workflows and interviewing the affected employees, we analysed the medication workflow processes from admission to discharge of seven representative departments of a large university hospital before and early after implementation of a newly defined best-practice process. To investigate the implementation impact, following measures were determined overall and for five key process steps: quality of medication documentation as measured by predefined criteria, the adherence to the best-practice process (range 0%-100%), workload and potential shifts in responsibilities.

RESULTS

Already early after implementation, all departments met the legal requirements and the quality of the medication documentation increased from low to high quality in most departments. Mean adherence to the best-practice process was 77% (range 60%-100%) with strictest adherence of 100% in one department. Thereby, the number of process steps and hence, likely also the workload increased in all departments. New tasks were mainly performed by physicians and in one department by pharmacists.

CONCLUSIONS

The new lawful best-practice process led to a higher quality in medication documentation at the cost of a higher workload for physicians, potentially limiting time for other care tasks. Therefore, it could be important to define areas of the medication documentation process in which physicians could be supported by other professions or new tools facilitating accurate medication documentation as the basis of continuity of care.

Prevalence of adverse drug reactions in the primary care setting: A systematic review and meta-analysis

BACKGROUND

Adverse drug reactions (ADRs) represent a major cause of iatrogenic morbidity and mortality in patient care. While a substantial body of work has been undertaken to characterise ADRs in the hospital setting, the overall burden of ADRs in the primary care remains unclear.

OBJECTIVES

To investigate the prevalence of ADRs in the primary care setting and factors affecting the heterogeneity of the estimates.

METHODS

Studies were identified through searching of Medline, Embase, CINAHL and IPA databases. We included observational studies that reported information on the prevalence of ADRs in patients receiving primary care. Disease and treatment specific studies were excluded. Quality of the included studies were assessed using Smyth ADRs adapted scale. A random-effects model was used to calculate the pooled estimate. Potential source of heterogeneity, including age groups, ADRs definitions, ADRs detection methods, study setting, quality of the studies, and sample size, were investigated using sub-group analysis and meta-regression.

RESULTS

Thirty-three studies with a total study population of 1,568,164 individuals were included. The pooled prevalence of ADRs in the primary care setting was 8.32% (95% CI, 7.82, 8.83). The percentage of preventable ADRs ranged from 12.35-37.96%, with the pooled estimate of 22.96% (95% CI, 7.82, 38.09). Cardiovascular system drugs were the most commonly implicated medication class. Methods of ADRs detection, age group, setting, and sample size contributed significantly to the heterogeneity of the estimates.

CONCLUSION

ADRs constitute a significant health problem in the primary care setting. Further research should focus on examining whether ADRs affect subsequent clinical outcomes, particularly in high-risk therapeutic areas. This information may better inform strategies to reduce the burden of ADRs in the primary care setting.

Management of hyperkalemia during treatment with mineralocorticoid receptor blockers: findings from esaxerenone

The nonsteroidal mineralocorticoid receptor (MR) blocker esaxerenone has demonstrated good antihypertensive activity in a variety of patients, including those with uncomplicated grade I-III hypertension, hypertension with moderate renal dysfunction, hypertension with type 2 diabetes mellitus with albuminuria, and hypertension associated with primary aldosteronism. Hyperkalemia has long been recognized as a potential side effect occurring during treatment with MR blockers, but there is a lack of understanding and guidance about the appropriate management of hyperkalemia during antihypertensive therapy with MR blockers, especially in regard to the newer agent esaxerenone. In this article, we first highlight risk factors for hyperkalemia, including advanced chronic kidney disease, diabetes mellitus, cardiovascular disease, age, and use of renin-angiotensin-aldosterone system inhibitors. Next, we examine approaches to prevention and management, including potassium monitoring, diet, and the use of appropriate therapeutic techniques. Finally, we summarize the currently available data for esaxerenone and hyperkalemia. Proper management of serum potassium is required to ensure safe clinical use of MR blockers, including awareness of at-risk patient groups, choosing appropriate dosages for therapy initiation and dosage titration, and monitoring of serum potassium during therapy. It is critical that physicians take such factors into consideration to optimize MR blocker therapy in patients with hypertension.

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.

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.

Population Pharmacokinetics of Candesartan in Patients with Chronic Heart Failure

Heart failure (HF) causes pathological changes in multiple organs, thus affecting the pharmacokinetics (PK) of drugs. The aim of this study was to investigate the PK of candesartan in patients with HF while examining significant covariates and their related impact on estimated clearance using a population PK (Pop‐PK) modeling approach. Data from a prospective, multicenter study were used. Modeling and simulations were conducted using Nonlinear Mixed‐Effects Modeling (NONMEM) and R software. A total of 281 white patients were included to develop the Pop‐PK model. The final model developed for apparent oral clearance (CL/F) included weight, estimated glomerular filtration rate (eGFR), and diabetes, which partly explained its interindividual variability. The mean CL/F value estimated was 7.6 L/h (1.7–22.6 L/h). Simulations revealed that an important decrease in CL/F (> 25%) is obtained with the combination of the factors retained in the final model. Considering these factors, a more individualized approach of candesartan dosing should be investigated in patients with HF.

Development and Validation of a Deep-Learning Model to Screen for Hyperkalemia From the Electrocardiogram

Importance

For patients with chronic kidney disease (CKD), hyperkalemia is common, associated with fatal arrhythmias, and often asymptomatic, while guideline-directed monitoring of serum potassium is underused. A deep-learning model that enables noninvasive hyperkalemia screening from the electrocardiogram (ECG) may improve detection of this life-threatening condition.

Objective

To evaluate the performance of a deep-learning model in detection of hyperkalemia from the ECG in patients with CKD.

Design, Setting, and Participants

A deep convolutional neural network (DNN) was trained using 1 576 581 ECGs from 449 380 patients seen at Mayo Clinic, Rochester, Minnesota, from 1994 to 2017. The DNN was trained using 2 (leads I and II) or 4 (leads I, II, V3, and V5) ECG leads to detect serum potassium levels of 5.5 mEq/L or less (to convert to millimoles per liter, multiply by 1) and was validated using retrospective data from the Mayo Clinic in Minnesota, Florida, and Arizona. The validation included 61 965 patients with stage 3 or greater CKD. Each patient had a serum potassium count drawn within 4 hours after their ECG was recorded. Data were analyzed between April 12, 2018, and June 25, 2018.

Exposures

Use of a deep-learning model.

Main Outcomes and Measures

Area under the receiver operating characteristic curve (AUC) and sensitivity and specificity, with serum potassium level as the reference standard. The model was evaluated at 2 operating points, 1 for equal specificity and sensitivity and another for high (90%) sensitivity.

Results

Of the total 1 638 546 ECGs, 908 000 (55%) were from men. The prevalence of hyperkalemia in the 3 validation data sets ranged from 2.6% (n = 1282 of 50 099; Minnesota) to 4.8% (n = 287 of 6011; Florida). Using ECG leads I and II, the AUC of the deep-learning model was 0.883 (95% CI, 0.873-0.893) for Minnesota, 0.860 (95% CI, 0.837-0.883) for Florida, and 0.853 (95% CI, 0.830-0.877) for Arizona. Using a 90% sensitivity operating point, the sensitivity was 90.2% (95% CI, 88.4%-91.7%) and specificity was 63.2% (95% CI, 62.7%-63.6%) for Minnesota; the sensitivity was 91.3% (95% CI, 87.4%-94.3%) and specificity was 54.7% (95% CI, 53.4%-56.0%) for Florida; and the sensitivity was 88.9% (95% CI, 84.5%-92.4%) and specificity was 55.0% (95% CI, 53.7%-56.3%) for Arizona.

Conclusions and Relevance

In this study, using only 2 ECG leads, a deep-learning model detected hyperkalemia in patients with renal disease with an AUC of 0.853 to 0.883. The application of artificial intelligence to the ECG may enable screening for hyperkalemia. Prospective studies are warranted.

Mineral and Electrolyte Disorders With SGLT2i Therapy

The newly developed sodium‐glucose cotransporter 2 inhibitors (SGLT2is) effectively modulate glucose metabolism in diabetes. Although clinical data suggest that SGLT2is (empagliflozin, dapagliflozin, ertugliflozin, canagliflozin, ipragliflozin) are safe and protect against renal and cardiovascular events, very little attention has been dedicated to the effects of these compounds on different electrolytes. As with other antidiabetic compounds, some effects on water and electrolytes balance have been documented. Although the natriuretic effect and osmotic diuresis are expected with SGLT2is, these compounds may also modulate urinary potassium, magnesium, phosphate, and calcium excretion. Notably, they have had no effect on plasma sodium levels and promoted only small increases in serum potassium and magnesium concentrations in clinical trials. Moreover, SGLT2is may induce an increase in serum phosphate, FGF‐23, and PTH; reduce 1,25‐dihydroxyvitamin D; and generate normal serum calcium. Some published and preliminary reports, as well as unconfirmed reports have suggested an association with bone fractures. Some homeostasis perturbations are transient, whereas others may persist, suggesting that the administration of SGLT2is may affect electrolyte balances in exposed subjects. Although current evidence supports their safety, additional efforts are needed to elucidate the long‐term impact of these compounds on chronic kidney disease, mineral metabolism, and bone health. Indeed, the limited follow‐up studies and the heterogeneity of the case‐mix of different randomized controlled trials preclude a definitive answer on the impact of these compounds on long‐term outcomes such as the risk of bone fracture. Here we review the current understanding of the mechanisms involved in electrolyte handling and the available data on the clinical implications of electrolytes and mineral metabolism perturbations induced by SGLT2i administration. © 2019 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

Predictors for repeated hyperkalemia and potassium trajectories in high-risk patients - A population-based cohort study

Understanding predictors and trajectories of increased potassium may inform testing and treatment of hyperkalemia. We examined predictors for repeated hyperkalemia among patients after first-time renin angiotensin system inhibitor (RASi) prescription, chronic kidney disease (CKD), or chronic heart failure (CHF); and we also examined potassium trajectories in these patients after their first hyperkalemia event. We used Danish population-based registries to identify all patients with first-time RASi prescription, incident CKD, or incident CHF (2000–2012). For patients with a first hyperkalemia event, potassium trajectories over the following 6 months were examined. The predictors associated with repeated hyperkalemia were assessed, with repeated hyperkalemia defined as a potassium test >5.0 mmol/L after the first event within 6 months. Overall 262,375 first-time RASi users, 157,283 incident CKD patients, and 14,600 incident CHF patients were included. Of patients with a first hyperkalemia event, repeated hyperkalemia within 6 months occurred in 37% of RASi users, 40% with CKD, and 49% of patients with CHF. Predictors included severe hyperkalemia, low eGFR, diabetes, and spironolactone use. In all cohorts, the median potassium levels declined over 2–4 weeks after a hyperkalemia event for the first time, but reverted to levels higher than before the initial hyperkalemia event in those who had repeated hyperkalemia. Following hyperkalemia, discontinuation of RASi and spironolactone was common in the RASi and CHF cohorts. Repeated hyperkalemia was common among the explored cohorts. The first hyperkalemia event was an indicator of increased median potassium levels. Predictors may identify patients likely to benefit from intensified monitoring and intervention.

Technology-Enabled Outreach to Patients Taking High-Risk Medications Reduces a Quality Gap in Completion of Clinical Laboratory Testing

Clinical laboratory quality improvement (QI) efforts can include population test utilization. The authors used a health care organization's Medical Data Warehouse (MDW) to characterize a gap in guideline-concordant laboratory testing recommended for safe use of antirheumatic agents, then tested the effectiveness of laboratory-led, technology-enabled outreach to patients at reducing this gap. Data linkages available through the Kaiser Permanente Colorado MDW and electronic health record were used to identify ambulatory adults taking antirheumatic agents who were due/overdue for alanine aminotransferase (ALT), aspartate aminotransferase (AST), complete blood count (CBC), or serum creatinine (SCr) testing. Outreach was implemented using an interactive voice response system to send patients text or phone call reminders. Interrupted time series analysis was used to estimate reminder effectiveness. Rates of guideline-concordant testing and testing timeliness in baseline vs. intervention periods were determined using generalized linear models for repeated measures. Results revealed a decrease in percentage of 3763 patients taking antirheumatic agents due/overdue for testing at any given time: baseline 24.3% vs. intervention 17.5% (P < 0.001). Among 3205 patients taking conventional antirheumatic agents, concordance for all ALT testing was baseline 52.8% vs. intervention 65.4% (P < 0.001) among patients chronically using these agents and baseline 20.6% vs. intervention 26.1% (P < 0.001) among patients newly starting these agents. The 95^th percentiles for days to ALT testing were baseline 149 vs. intervention 117 among chronic users and baseline 134 vs. intervention 92 among new starts. AST, CBC, and SCr findings were similar. Technology-enabled outreach reminding patients to obtain laboratory testing improves health care system outcomes.

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.

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

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

Identifying Preanalytic and Postanalytic Laboratory Quality Gaps Using a Data Warehouse and Structured Multidisciplinary Process

CONTEXT.—

The laboratory total testing process includes preanalytic, analytic, and postanalytic phases, but most laboratory quality improvement efforts address the analytic phase. Expanding quality improvement to preanalytic and postanalytic phases via use of medical data warehouses, repositories that include clinical, utilization, and administrative data, can improve patient care by ensuring appropriate test utilization. Cross-department, multidisciplinary collaboration to address gaps and improve patient and system outcomes is beneficial.

OBJECTIVE.—

To demonstrate medical data warehouse utility for characterizing laboratory-associated quality gaps amenable to preanalytic or postanalytic interventions.

DESIGN.—

A multidisciplinary team identified quality gaps. Medical data warehouse data were queried to characterize gaps. Organizational leaders were interviewed about quality improvement priorities. A decision aid with elements including national guidelines, local and national importance, and measurable outcomes was completed for each gap.

RESULTS.—

Gaps identified included (1) test ordering; (2) diagnosis, detection, and documentation, and (3) high-risk medication monitoring. After examination of medical data warehouse data including enrollment, diagnoses, laboratory, pharmacy, and procedures for baseline performance, high-risk medication monitoring was selected, specifically alanine aminotransferase, aspartate aminotransferase, complete blood count, and creatinine testing among patients receiving disease-modifying antirheumatic drugs. The test utilization gap was in monitoring timeliness (eg, >60% of patients had a monitoring gap exceeding the guideline recommended frequency). Other contributors to selecting this gap were organizational enthusiasm, regulatory labeling, and feasibility of a significant laboratory role in addressing the gap.

CONCLUSIONS.—

A multidisciplinary process facilitated identification and selection of a laboratory medicine quality gap. Medical data warehouse data were instrumental in characterizing gaps.

Chronic Hyperkalemia in Cardiorenal Patients: Risk Factors, Diagnosis, and New Treatment Options

Chronic hyperkalemia (HK) is a serious medical condition that often manifests in patients with chronic kidney disease (CKD) and heart failure (HF) leading to poor outcomes and necessitating careful management by cardionephrologists. CKD, HF, diabetes, and renin-angiotensin-aldosterone system inhibitors use is known to induce HK. Current therapeutic options are not optimal, as pointed out by a large number of CKD and HF patients with HK. The following review will focus on the main risk factors for developing HK and also aims to provide a guide for a correct diagnosis and present new approaches to therapy.

Investigation of the Role of a Supplementation with Taurine on the Effects of Hypoglycemic-Hypotensive Therapy Against Diabetes-Induced Nephrotoxicity in Rats

This study has examined the role of supplementing a treatment of diabetic rats with captopril (CAP), metformin (MET) or CAP-MET with the antioxidant amino acid taurine (TAU) on biochemical indices of diabetes-induced metabolic changes, oxidative stress and nephropathy. To this end, groups of 6 male Sprague-Dawley rats (250-375 g) were made diabetic with a single, 60 mg/kg, intraperitoneal dose of streptozotocin (STZ) in 10 mM citrate buffer pH 4.5 and, after 14 days, treated daily for up to 42 days with either a single oral dose of CAP (0.15 mM/kg), MET (2.4 mM/kg) or TAU (2.4 mM/kg), or with a binary or tertiary combination of these agents. Rats receiving only 10 mM citrate buffer pH 4.5 or only STZ served as negative and positive controls, respectively. All rats were sacrificed by decapitation on day 57 and their blood and kidneys collected. In addition, a 24 h urine sample was collected starting on day 56. Compared to normal rats, untreated diabetic ones exhibited frank hyperglycemia (+313%), hypoinsulinemia (-76%) and elevation of the glycated hemoglobin value (HbA1c, +207%). Also they showed increased plasma levels of Na+ (+35%), K+ (+56%), creatinine (+232%), urea nitrogen (+158%), total protein (-53%) and transforming growth factor-β1 (TGF-β1, 12.4-fold) values. These changes were accompanied by increases in the renal levels of malondialdehyde (MDA, +42%), by decreases in the renal glutathione redox state (-71%), and activities of catalase (-70%), glutathione peroxidase (-71%) and superoxide dismutase (-85%), and by moderate decreases of the urine Na+ (-33%) and K+ (-39%) values. Following monotherapy, MET generally showed a greater attenuating effect than CAP or TAU on the changes in circulating glucose, insulin and HbA1c levels, urine total protein, and renal SOD activity; and CAP appeared more potent than TAU and MET, in that order, in antagonizing the changes in plasma creatinine and urea nitrogen levels. On the other hand, TAU generally provided a greater protection against changes in glutathione redox state and in CAT and GPx activities, with other actions falling in potency between those of CAP and MET. Adding TAU to a treatment with CAP, but not to one with MET, led to an increase in protective action relative to a treatment with drug alone. On the other hand, the actions of CAP-MET, which were about equipotent with those of MET, became enhanced in the presence of TAU, particularly against the changes of the glutathione redox state and activities of antioxidant enzymes. In short, the present results suggest that the addition of TAU to a treatment of diabetes with CAP or CAP-MET, and sometimes to one with MET, will lead to a gain in protective potency against changes in indices of glucose metabolism and of renal functional impairment and oxidative stress.

Hyperkalaemia in people with diabetes: occurrence, risk factors and outcomes in a Danish population-based cohort study

AIMS

To examine the incidence, risk factors and clinical outcomes of hyperkalaemia in people with diabetes in a real-world setting.

METHODS

Using Danish health registries, we identified a population-based cohort of people with first-time drug-treated diabetes, in the period 2000-2012. First, the cumulative incidence of hyperkalaemia, defined as first blood test with potassium level >5.0 mmol/l after diabetes treatment initiation, was ascertained. Second, in a case-control analysis, risk factors were compared in people with vs without hyperkalaemia. Third, clinical outcomes were assessed among individuals with hyperkalaemia in a before-after analysis, and among people with and without hyperkalaemia in a matched cohort analysis.

RESULTS

Of 68 601 individuals with diabetes (median age 62 years, 47% women), 16% experienced hyperkalaemia (incidence rate 40 per 1000 person-years) during a mean follow-up of 4.1 years. People who developed hyperkalaemia had a higher prevalence of chronic kidney disease [prevalence ratio 1.74 (95% CI 1.68-1.81)], heart failure [prevalence ratio 2.35 (95% CI 2.18-2.54)], use of angiotensin-converting enzyme inhibitors [prevalence ratio 1.24 (95% CI 1.20-1.28)], use of spironolactone [prevalence ratio 2.68 (95% CI 2.48-2.88)] and potassium supplements [prevalence ratio 1.59 (95% CI 1.52-1.67)]. In people with diabetes who developed hyperkalaemia, 31% were acutely hospitalized within 6 months before hyperkalaemia, increasing to 50% 6 months after hyperkalaemia [before-after risk ratio 1.67 (95% CI 1.61-1.72)]. The 6-month mortality rate after hyperkalaemia was 20%. Compared with matched individuals without hyperkalaemia, the hazard ratio for death was 6.47 (95% CI 5.81-7.21).

CONCLUSIONS

One in six newly diagnosed people with diabetes experienced a hyperkalaemic event, which was associated with severe clinical outcomes and death.

The prevalence of hyperkalemia in the United States

OBJECTIVE

The retrospective study aimed to estimate prevalence of hyperkalemia using a large US commercial claims database.

METHODS

Adults with serum potassium lab data (2010 to 2014) and ≥1 calendar year of data were included from a large US commercial claims database. Hyperkalemia was defined as ≥2 serum potassium measurements >5.0 mEq/L or one hyperkalemia diagnosis code (ICD-9-CM, 276.7) or one sodium polystyrene sulfonate fill. Hyperkalemia prevalence was estimated for the overall population and subgroups with hyperkalemia-related comorbidities by calendar year. Hyperkalemia prevalence was also standardized to the US population to estimate the number of US adults with hyperkalemia.

RESULTS

The analysis included 2,270,635 patients (2010-2014). The annual prevalence of hyperkalemia in the overall population was 1.57% in 2014, with higher rates observed in patients with chronic kidney disease (CKD), heart failure, diabetes and hypertension. Among patients with CKD and/or heart failure, the 2014 annual prevalence was 6.35%. Among patients with hyperkalemia, 48.43% had CKD and/or heart failure in 2014. The prevalence of hyperkalemia was higher in patients with more severe CKD, as well as older patients and men. Extrapolating those results to the US population supports that 1.55% or 3.7 million US adults had hyperkalemia in 2014.

CONCLUSIONS

An estimated 3.7 million US adults had hyperkalemia in 2014, and this prevalence rate has increased since 2010. In patients with CKD and/or heart failure, the annual prevalence of hyperkalemia was 6.35% in 2014, and about half of all patients with hyperkalemia have either CKD and/or heart failure.

Adherence to guidelines for creatinine and potassium monitoring and discontinuation following renin-angiotensin system blockade: a UK general practice-based cohort study

OBJECTIVES

To examine adherence to serum creatinine and potassium monitoring and discontinuation guidelines following initiation of treatment with ACE inhibitors (ACEI) or angiotensin receptor blockers (ARBs); and whether high-risk patients are monitored.

DESIGN

A general practice-based cohort study using electronic health records from the UK Clinical Practice Research Datalink and Hospital Episode Statistics.

SETTING

UK primary care, 2004-2014.

SUBJECTS

223 814 new ACEI/ARB users.

MAIN OUTCOME MEASURES

Proportion of patients with renal function monitoring before and after ACEI/ARB initiation; creatinine increase ≥30% or potassium levels >6 mmol/L at first follow-up monitoring; and treatment discontinuation after such changes. Using logistic regression models, we also examined patient characteristics associated with these biochemical changes, and with follow-up monitoring within the guideline recommendation of 2 weeks after treatment initiation.

RESULTS

10% of patients had neither baseline nor follow-up monitoring of creatinine within 12 months before and 2 months after initiation of an ACEI/ARB, 28% had monitoring only at baseline, 15% only at follow-up, and 47% both at baseline and follow-up. The median period between the most recent baseline monitoring and drug initiation was 40 days (IQR 12-125 days). 34% of patients had baseline creatinine monitoring within 1 month before initiating therapy, but <10% also had the guideline-recommended follow-up test recorded within 2 weeks. Among patients experiencing a creatinine increase ≥30% (n=567, 1.2%) or potassium level >6 mmol/L (n=191, 0.4%), 80% continued treatment. Although patients with prior myocardial infarction, hypertension or baseline potassium >5 mmol/L were at high risk of ≥30% increase in creatinine after ACEI/ARB initiation, there was no evidence that they were more frequently monitored.

CONCLUSIONS

Only one-tenth of patients initiating ACEI/ARB therapy receive the guideline-recommended creatinine monitoring. Moreover, the vast majority of the patients fulfilling postinitiation discontinuation criteria for creatinine and potassium increases continue on treatment.

Potassium Homeostasis, Oxidative Stress, and Human Disease

Potassium is the most abundant cation in the intracellular fluid and it plays a vital role in the maintenance of normal cell functions. Thus, potassium homeostasis across the cell membrane, is very critical because a tilt in this balance can result in different diseases that could be life threatening. Both Oxidative stress (OS) and potassium imbalance can cause life threatening health conditions. OS and abnormalities in potassium channel have been reported in neurodegenerative diseases. This review highlights the major factors involved in potassium homeostasis (dietary, hormonal, genetic, and physiologic influences), and discusses the major diseases and abnormalities associated with potassium imbalance including hypokalemia, hyperkalemia, hypertension, chronic kidney disease, and Gordon's syndrome, Bartter syndrome, and Gitelman syndrome.

Methods for using clinical laboratory test results as baseline confounders in multi-site observational database studies when missing data are expected

PURPOSE

Our purpose was to quantify missing baseline laboratory results, assess predictors of missingness, and examine performance of missing data methods.

METHODS

Using the Mini-Sentinel Distributed Database from three sites, we selected three exposure-outcome scenarios with laboratory results as baseline confounders. We compared hazard ratios (HRs) or risk differences (RDs) and 95% confidence intervals (CIs) from models that omitted laboratory results, included only available results (complete cases), and included results after applying missing data methods (multiple imputation [MI] regression, MI predictive mean matching [PMM] indicator).

RESULTS

Scenario 1 considered glucose among second-generation antipsychotic users and diabetes. Across sites, glucose was available for 27.7-58.9%. Results differed between complete case and missing data models (e.g., olanzapine: HR 0.92 [CI 0.73, 1.12] vs 1.02 [0.90, 1.16]). Across-site models employing different MI approaches provided similar HR and CI; site-specific models provided differing estimates. Scenario 2 evaluated creatinine among individuals starting high versus low dose lisinopril and hyperkalemia. Creatinine availability: 44.5-79.0%. Results differed between complete case and missing data models (e.g., HR 0.84 [CI 0.77, 0.92] vs. 0.88 [0.83, 0.94]). HR and CI were identical across MI methods. Scenario 3 examined international normalized ratio (INR) among warfarin users starting interacting versus noninteracting antimicrobials and bleeding. INR availability: 20.0-92.9%. Results differed between ignoring INR versus including INR using missing data methods (e.g., RD 0.05 [CI -0.03, 0.13] vs 0.09 [0.00, 0.18]). Indicator and PMM methods gave similar estimates.

CONCLUSION

Multi-site studies must consider site variability in missing data. Different missing data methods performed similarly. Copyright © 2016 John Wiley & Sons, Ltd.

Hyporeninemic hypoaldosteronism and diabetes mellitus: Pathophysiology assumptions, clinical aspects and implications for management

Patients with diabetes mellitus (DM) frequently develop electrolyte disorders, including hyperkalemia. The most important causal factor of chronic hyperkalemia in patients with diabetes is the syndrome of hyporeninemic hypoaldosteronism (HH), but other conditions may also contribute. Moreover, as hyperkalemia is related to the blockage of the renin-angiotensin-aldosterone system (RAAS) and HH is most common among patients with mild to moderate renal insufficiency due to diabetic nephropathy (DN), the proper evaluation and management of these patients is quite complex. Despite its obvious relationship with diabetic nephropathy, HH is also related to other microvascular complications, such as DN, particularly the autonomic type. To confirm the diagnosis, plasma aldosterone concentration and the levels of renin and cortisol are measured when the RAAS is activated. In addition, synthetic mineralocorticoid and/or diuretics are used for the treatment of this syndrome. However, few studies on the implications of HH in the treatment of patients with DM have been conducted in recent years, and therefore little, if any, progress has been made. This comprehensive review highlights the findings regarding the epidemiology, diagnosis, and management recommendations for HH in patients with DM to clarify the diagnosis of this clinical condition, which is often neglected, and to assist in the improvement of patient care.

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.

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.

Significance of serum potassium level monitoring during the course of post-operative rehabilitation in patients with hypokalemia

OBJECTIVE

Our objective was to evaluate the significance of pre-hospital and post-operative serum potassium level monitoring and hypokalemia intervention in laparotomy patients with hypokalemia.

METHOD

A total of 118 laparotomy patients with hypokalemia were randomly divided into an intervention group (N = 60) and a control group (N = 58). Blood samples were collected for measurement of potassium levels at various time points (pre-admission, admission, 24 h and 48 h post-operation) for both groups. Hypokalemia interventions were administered to patients in the intervention group in the pre-admission period and the post-operative period. Visceral dynamics were assessed after laparotomy in both groups.

RESULT

Average serum potassium levels at admission, time period of drinking, and time of first bowel sound after laparotomy differed significantly (p < 0.001) between the two groups. Average serum potassium levels, first time of defecation, urination, and ambulation at 24 h and 48 h post-operation differed significantly (p < 0.05) between the two groups.

CONCLUSION

An optimal pathway of serum potassium monitoring not only saves limited ward space but also allows for early correction of hypokalemia in patients undergoing laparotomy.

Diabetes mellitus and electrolyte disorders

Diabetic patients frequently develop a constellation of electrolyte disorders. These disturbances are particularly common in decompensated diabetics, especially in the context of diabetic ketoacidosis or nonketotic hyperglycemic hyperosmolar syndrome. These patients are markedly potassium-, magnesium- and phosphate-depleted. Diabetes mellitus (DM) is linked to both hypo- and hyper-natremia reflecting the coexistence of hyperglycemia-related mechanisms, which tend to change serum sodium to opposite directions. The most important causal factor of chronic hyperkalemia in diabetic individuals is the syndrome of hyporeninemic hypoaldosteronism. Impaired renal function, potassium-sparing drugs, hypertonicity and insulin deficiency are also involved in the development of hyperkalemia. This article provides an overview of the electrolyte disturbances occurring in DM and describes the underlying mechanisms. This insight should pave the way for pathophysiology-directed therapy, thus contributing to the avoidance of the several deleterious effects associated with electrolyte disorders and their treatment.

Prediction and management of hyperkalemia across the spectrum of chronic kidney disease

Hyperkalemia commonly limits optimizing treatment to slow stage 3 or higher chronic kidney disease (CKD) progression. The risk of hyperkalemia is linked to dietary potassium intake, level of kidney function, concomitant diseases that may affect potassium balance such as diabetes, and use of medications that influence potassium excretion. The risk predictors for developing hyperkalemia are an estimated glomerular filtration rate of less than 45 mL/min/1.73 m(2) and a serum potassium level greater than 4.5 mEq/L in the absence of blockers of the renin-angiotensin-aldosterone system (RAAS). Generally, monotherapy with RAAS blockers does not increase risk substantially unless hypotension or volume depletion occur. Dual RAAS blockade involving any combination of an angiotensin-converting enzyme inhibitor, angiotensin-receptor blocker, renin inhibition, or aldosterone-receptor blocker markedly increases the risk of hyperkalemia in patients with stage 3 or higher CKD. Moreover, dual RAAS blockade further reduces albuminuria by 25% to 30% compared with monotherapy, it has failed to show a benefit on CKD progression or cardiovascular outcome, and thus is not indicated in such patients because of its marked increase in hyperkalemia potential. Although sodium polystyrene resins exist to manage hyperkalemia in patients requiring therapy that increases serum potassium levels, they are not well tolerated. Newer, more predictable, better-tolerated polymers to bind potassium are on the horizon and may be approved within the next 1 to 2 years.

Monitoring and adverse events in relation to ACE inhibitor/angiotensin receptor blocker initiation in people with diabetes in general practice: a population database study

BACKGROUND AND AIM

To determine whether angiotensin-converting enzyme inhibitor/angiotensin receptor blocker (ACEI/ARB) initiation in people with diabetes is monitored as recommended by recent guidelines and the incidence of associated adverse renal events.

DESIGN

Retrospective population database analysis of 4056 people in Tayside, Scotland with type 2 diabetes prescribed an ACEI/ARB between 1 January 2005 and 31 December 2009.

METHOD

Measurement of urea and electrolytes (U&Es) before and after ACEI/ARB initiation and renal adverse events; defined as a ≥30% rise in serum creatinine and post-initiation potassium of ≥5.6 mmol/L. Associations of adverse events with patient demographics or co-prescription of drugs with known renal effects were examined.

RESULTS

Overall, 89% of initiations were with an ACE inhibitor. A total of 18.84% (CI 95% 18.82-18.86) of patients initiating ACE inhibitor or ARB had U&Es measured in the 90 days before initiation and within 5-14 days after initiation. Only 1.7% of patients had an adverse renal event. Patients prescribed with an ARB were less likely to be monitored than those prescribed with an ACE inhibitor, but no less likely to suffer harm.

CONCLUSIONS

Current clinical practice of biochemical monitoring of ACE inhibitor/ARB is poor, but adverse events are rare. Further studies with serial U&Es are needed to establish the critical time window for adverse renal events and evaluate whether intensive biochemical monitoring recommended is required in low-risk groups.

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

WHAT IS KNOWN AND OBJECTIVE

Angiotensin receptor blockers (ARBs) frequently induce hyperkalaemia in high-risk patients. Early detection of hyperkalaemia can reduce the subsequent harmful effects. This study was performed to examine the onset time of hyperkalaemia after ARB therapy.

METHODS

We carried out a retrospective analysis to determine the onset time of hyperkalaemia (serum potassium >5·5 mm) among hospitalized patients newly starting ARB therapy between 2004 and 2012, in a tertiary teaching hospital. Predefined possible risk factors and concomitant medications were evaluated.

RESULTS AND DISCUSSION

During the 97-month study period, a total of 4267 hospitalized patients started ARBs as new drugs and 225 patients showed hyperkalaemia. A significantly increased risk of hyperkalaemia was detected among patients with a high baseline potassium [odds ratio (OR) 6·0] and those who took non-potassium-sparing diuretics (OR 2·2) or potassium supplements (OR 1·6). A high glomerular filtration rate (GFR) was associated with a lower risk of hyperkalaemia (OR 0·992). Fifty-two percentage of hyperkalaemic events occurred within the first week after initiation of ARB therapy. The highest frequency of hyperkalaemia occurred on the first day after initiation of ARBs. Hyperkalaemia occurred earlier in patients with a high baseline serum potassium level, reduced GFR, diabetes and in those without heart failure.

WHAT IS NEW AND CONCLUSION

Hyperkalaemia occurs most frequently at the beginning of ARB therapy in hospitalized patients. Monitoring of serum potassium and estimated GFR after initiation of ARBs should be started within a few days or not later than 1 week, especially in patients with risk factors.

Patient- and physician-related risk factors for hyperkalaemia in potassium-increasing drug-drug interactions

PURPOSE

Hyperkalaemia due to potassium-increasing drug-drug interactions (DDIs) is a clinically important adverse drug event. The purpose of this study was to identify patient- and physician-related risk factors for the development of hyperkalaemia.

METHODS

The risk for adult patients hospitalised in the University Hospital Zurich between 1 December 2009 and 31 December 2011 of developing hyperkalaemia was correlated with patient characteristics, number, type and duration of potassium-increasing DDIs and frequency of serum potassium monitoring.

RESULTS

The 76,467 patients included in this study were prescribed 8,413 potentially severe potassium-increasing DDIs. Patient-related characteristics associated with the development of hyperkalaemia were pulmonary allograft [relative risk (RR) 5.1; p < 0.0001), impaired renal function (RR 2.7; p < 0.0001), diabetes mellitus (RR 1.6; p = 0.002) and female gender (RR 1.5; p = 0.007). Risk factors associated with medication were number of concurrently administered potassium-increasing drugs (RR 3.3 per additional drug; p < 0.0001) and longer duration of the DDI (RR 4.9 for duration ≥6 days; p < 0.0001). Physician-related factors associated with the development of hyperkalaemia were undetermined or elevated serum potassium level before treatment initiation (RR 2.2; p < 0.001) and infrequent monitoring of serum potassium during a DDI (interval >48 h: RR 1.6; p < 0.01).

CONCLUSION

Strategies for reducing the risk of hyperkalaemia during potassium-increasing DDIs should consider both patient- and physician-related risk factors.

Electronic health record-based monitoring of primary care patients at risk of medication-related toxicity

BACKGROUND

Timely laboratory monitoring may reduce the potential harm associated with chronic medication use. A study was conducted to determine the proportion of patients receiving National Committee for Quality Assurance (NCQA)-recommended laboratory medication monitoring in a primary care setting and to assess the effect of electronic health record (EHR)-derived, paper-based, provider-specific feedback bulletins on subsequent patient receipt of medication monitoring.

METHODS

In a single-arm, pre-post intervention in two federally qualified community health centers in Baltimore, patients targeted were adults prescribed at least 6 months (in the preceding year) for at least one index medication (digoxin, statins, diuretics, angiotensin-converting enzyme inhibitors/ angiotensin II-receptor blockers) in a 12-month period (August 2008-July 2009).

RESULTS

Among the 2,013 patients for whom medication monitoring was recommended, 42% were overdue for monitoring at some point during the study. As the number of index medications the patient was prescribed increased, the likelihood of ever being overdue for monitoring decreased. Being listed on the provider-specific monitoring bulletin doubled the odds of a patient receiving recommended laboratory monitoring before the next measurement period (1-2 months). Limiting the intervention to the most overdue patients, however, mitigated its overall impact.

CONCLUSIONS

Recommended laboratory monitoring of chronic medications appears to be inconsistent in primary care, resulting in potential harm for individuals at risk for medication-related toxicity. EHRs may be an important component of systems designed to improve medication monitoring, but multimodal interventions will likely be needed to achieve high reliability.

Biochemical monitoring of patients treated with antihypertensive therapy for adverse drug reactions: a systematic review

Biochemical monitoring of patients treated with antihypertensive therapy is recommended in order to identify potential adverse reactions to treatment. We aimed to review the literature investigating the nature of biochemical monitoring in adults treated in primary care with antihypertensive drugs. Specifically, we wished to establish (i) the proportion of patients with biochemical baseline testing prior to the initiation of antihypertensive therapy; (ii) the proportion of patients with biochemical monitoring after initiation of antihypertensive therapy; (iii) the patient characteristics associated with biochemical monitoring; (iv) the frequency of biochemical monitoring after the initiation of antihypertensive therapy; and (v) the relationship, if any, between biochemical monitoring and adverse patient outcomes. We searched MEDLINE, EMBASE and Google Scholar from 1948 to 31 December 2010 using a combination of text words and search terms. Retrospective and prospective cohort studies, cross-sectional studies, randomized controlled trials or quasi-randomized controlled trials, and audits of current clinical practice were included. Clinical trials, case reports and case series were excluded. Studies were included if they provided data on the proportion of patients treated with antihypertensive therapy in primary care who had any biochemical monitoring before or after the initiation of therapy. In total, 15 studies were included in our review, which used a wide variety of definitions of monitoring prior to and after the initiation of antihypertensive therapy. From 17% to 81% of patients treated with antihypertensive drugs had a baseline biochemical test and from 20% to 79% had any follow-up monitoring. In only 7 of the 12 studies that examined follow-up monitoring did more than half of the patients have any monitoring. Overall, this systematic review provides evidence that monitoring as recommended by published guidelines is not commonly undertaken. Only two studies were identified that examined patients with both baseline testing and follow-up monitoring. Omission of one or the other limits the ability to analyse the effect of treatment on electrolyte concentrations or renal function. There is limited research on the patient factors associated with monitoring and further work is required to determine the impact of monitoring on adverse patient outcomes. Important barriers to effective monitoring exist and this review emphasizes that these have not yet been overcome.

Baseline and follow-up laboratory monitoring of cardiovascular medications

BACKGROUND

Laboratory monitoring of medications is typically used to establish safety prior to drug initiation and to detect drug-related injury following initiation. It is unclear whether black box warnings (BBWs) as well as evidence- and consensus-based clinical guidelines increase the likelihood of appropriate monitoring.

OBJECTIVE

To determine the proportion of patients newly initiated on selected cardiovascular medications with baseline assessment and follow-up laboratory monitoring and compare the prevalence of laboratory testing for drugs with and without BBWs and guidelines.

METHODS

This cross-sectional study included patients aged 18 years or older from a large multispecialty group practice who were prescribed a cardiovascular medication (angiotensin converting enzyme inhibitors, angiotensin II receptor blockers, amiodarone, digoxin, lipid-lowering agents, diuretics, and potassium supplements) between January 1 and July 31, 2008. The primary outcome measure was laboratory test ordering for baseline assessment and follow-up monitoring of newly initiated cardiovascular medications.

RESULTS

The number of new users of each study drug ranged from 49 to 1757 during the study period. Baseline laboratory test ordering across study drugs ranged from 37.4% to 94.8%, and follow-up laboratory test ordering ranged from 20.0% to 77.2%. Laboratory tests for drugs with baseline laboratory assessment recommendations in BBWs were more commonly ordered than for drugs without BBWs (86.4% vs 78.0%, p < 0.001). Drugs with follow-up monitoring recommendations in clinical guidelines had a lower prevalence of monitoring (33.1% vs 50.7%, p < 0.001).

CONCLUSIONS

Baseline assessment of cardiovascular medication monitoring is variable. Quality measurement of adherence to BBW recommendations may improve monitoring.

The positive predictive value of a hyperkalemia diagnosis in automated health care data

PURPOSE

Our objectives were to determine performance of coded hyperkalemia diagnosis at identifying (1) clinically evident hyperkalemia and (2) serum potassium>6 mmol/L.

METHODS

This retrospective observational study included 8722 patients with diabetes within an integrated healthcare system who newly initiated an angiotensin converting enzyme inhibitor, angiotensin receptor blocker, or spironolactone. The primary outcome was first hyperkalemia-associated event (hospitalization, emergency department visit or death within 24 hours of coded diagnosis and/or potassium≥6 mmol/L) during the first year of therapy. Medical records were reviewed.

RESULTS

Among a random sample of 99 patients not coded as having hyperkalemia, none had hyperkalemia upon record review. Among all 64 patients identified as having hyperkalemia, all had hospitalization or emergency department visit associated with coded diagnosis or elevated potassium. Of 55 with coded diagnosis, 42 (PPV 76%) had clinically evident hyperkalemia; 32 (PPV 58%) had potassium≥6. Of 9 identified using only potassium≥6, 7 (PPV 78%) had clinically evident hyperkalemia.

CONCLUSIONS

Nearly one-fourth of patients with coded diagnosis do not have clinically evident hyperkalemia and nearly one-half do not have potassium≥6. Because both false positives and negatives occur with coded diagnoses, medical record validation of hyperkalemia-associated outcomes is necessary.

Managing medications in clinically complex elders: "There's got to be a happy medium"

Multiple medication use is common in older adults and may ameliorate symptoms, improve and extend quality of life, and occasionally cure disease. Unfortunately, multiple medication use is also a major risk factor for prescribing and adherence problems, adverse drug events, and other adverse health outcomes. Using the case of an older patient taking multiple medications, this article summarizes the evidence-based literature about improving medication use and withdrawing specific drugs and drug classes. It also describes a systematic approach for how health professionals can assess and improve medication regimens to benefit patients and their caregivers and families.

Renin-angiotensin-aldosterone system blockade effects on the kidney in the elderly: benefits and limitations

The proportion of the population that is elderly (age>or=65 years) is growing across the world. The increasing longevity of humans results in a higher number of elderly patients' presenting with multiple chronic diseases such as hypertension, diabetes, and chronic kidney disease (CKD). These problems increase morbidity and mortality in the elderly. Overactivity of the renin-angiotensin-aldosterone system (RAAS) is associated with the development of hypertension, cardiovascular events, and CKD, so targeting the RAAS is a logical therapeutic approach. Elderly patients present special concerns regarding the benefits versus risks of using RAAS blockers. Plasma renin activity declines with age, which has been attributed to the effect of age-associated nephrosclerosis. Plasma aldosterone is also reduced with age, resulting in a greater risk for hyperkalemia in older individuals, especially when coupled with the age-associated decline in GFR. Moreover, the elderly have a higher frequency of concurrent conditions and are on many medications, which may further increase the risk for adverse effects of RAAS blocking agents. Unfortunately, there is a paucity of literature that is specifically aimed at studying elderly using the RAAS blockers. We present in our in-depth review data regarding benefits and limitations of the use of the RAAS blockades on the various sites along the RAAS pathway for elderly patients. Specific attention was given to the role of combination RAAS blockade therapy and higher monotherapy dosing in the treatment of hypertension in the elderly.