Trimethoprim-sulfamethoxazole and the risk of a hospital encounter with hyperkalemia: a matched population-based cohort study.

BACKGROUND: Trimethoprim-sulfamethoxazole (TMP-SMX) can cause hyperkalemia by reducing renal potassium excretion. We assessed the risk of hyperkalemia after initiating TMP-SMX versus amoxicillin and determined if this risk is modified by a patient's baseline kidney function [estimated glomerular filtration rate (eGFR)]. METHODS: We conducted a population-based cohort study in Ontario, Canada involving adults ≥66 years of age newly treated with TMP-SMX (n = 58 999) matched 1:1 with those newly treated with amoxicillin (2008-2020). The primary outcome was a hospital encounter with hyperkalemia defined by a laboratory serum potassium value ≥5.5 mmol/L within 14 days of antibiotic treatment. Secondary outcomes included a hospital encounter with acute kidney injury (AKI) and all-cause hospitalization. Risk ratios (RRs) were obtained using a modified Poisson regression. RESULTS: A hospital encounter with hyperkalemia occurred in 269/58 999 (0.46%) patients treated with TMP-SMX versus 80/58 999 (0.14%) in those treated with amoxicillin {RR 3.36 [95% confidence interval (CI) 2.62-4.31]}. The absolute risk of hyperkalemia in patients treated with TMP-SMX versus amoxicillin increased progressively with decreasing eGFR (risk difference of 0.12% for an eGFR ≥60 ml/min/1.73 m2, 0.42% for eGFR 45-59, 0.85% for eGFR 30-44 and 1.45% for eGFR <30; additive interaction P < .001). TMP-SMX versus amoxicillin was associated with a higher risk of a hospital encounter with AKI [RR 3.15 (95% CI 2.82-3.51)] and all-cause hospitalization [RR 1.43 (95% CI 1.34-1.53)]. CONCLUSIONS: The 14-day risk of a hospital encounter with hyperkalemia was higher in patients newly treated with TMP-SMX versus amoxicillin and the risk was highest in patients with a low eGFR.

The effect of micro-particle curcumin on chronic kidney disease progression: the MPAC-CKD randomized clinical trial.

BACKGROUND: Curcumin is a commonly used herbal supplement with anti-inflammatory and anti-fibrotic properties. Animal studies and small human trials suggest that curcumin reduces albuminuria in patients with chronic kidney disease (CKD). Micro-particle curcumin is a new, more bioavailable formulation of curcumin. METHODS: To determine whether micro-particle curcumin versus placebo slows the progression of albuminuric CKD we conducted a randomized, double-blind, placebo-controlled trial with 6-month follow-up. We included adults with albuminuria [a random urine albumin-to-creatinine ratio >30 mg/mmol (265 mg/g) or a 24-h urine collection with more than 300 mg of protein] and an estimated glomerular filtration rate (eGFR) between 15 and 60 mL/min/1.73 m2 within the 3 months before randomization. We randomly allocated participants 1:1 to receive micro-particle curcumin capsules (90 mg/day) or matching placebo for 6 months. After randomization, the co-primary outcomes were the changes in albuminuria and the eGFR. RESULTS: We enrolled 533 participants, but 4/265 participants in the curcumin group and 15/268 in the placebo group withdrew consent or became ineligible. The 6-month change in albuminuria did not differ significantly between the curcumin and placebo groups [geometric mean ratio 0.94, 97.5% confidence interval (CI) 0.82 to 1.08, P = .32]. Similarly, the 6-month change in eGFR did not differ between groups (mean between-group difference -0.22 mL/min/1.73 m2, 97.5% CI -1.38 to 0.95, P = .68). CONCLUSIONS: Ninety milligrams of micro-particle curcumin daily did not slow the progression of albuminuric CKD over 6 months. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02369549.

Higher-Dose Gabapentinoids and the Risk of Adverse Events in Older Adults With CKD: A Population-Based Cohort Study.

RATIONALE & OBJECTIVE: Gabapentinoids are opioid substitutes whose elimination by the kidneys is reduced as kidney function declines. To inform their safe prescribing in older adults with chronic kidney disease (CKD), we examined the 30-day risk of serious adverse events according to the prescribed starting dose. STUDY DESIGN: Population-based cohort study. SETTING & PARTICIPANTS: 74,084 older adults (64% women; median age, 79 [interquartile range, 73-85] years) with CKD (defined for this study as an estimated glomerular filtration rate <60 mL/min/1.73 m2 and excluding those receiving dialysis) and a newly prescribed gabapentinoid between 2008 and 2020 in Ontario, Canada. EXPOSURE: Higher-dose gabapentinoids (gabapentin >300 mg/d or pregabalin >75 mg/d) versus lower-dose gabapentinoids (gabapentin ≤300 mg/d or pregabalin ≤75 mg/d). OUTCOMES: The primary composite outcome was the 30-day risk of a hospital visit with encephalopathy, a fall, or a fracture or a hospitalization with respiratory depression. ANALYTICAL APPROACH: Comparison groups were balanced on indicators of baseline health using inverse probability of treatment weighting using propensity score analysis that generated a pseudosample for the reference group with a distribution of measured covariates similar to the exposed group. Weighted risk ratios were estimated using modified Poisson regression, and weighted risk differences were estimated using binomial regression. Prespecified subgroup analyses were conducted by estimated glomerular filtration rate category and type of gabapentinoid. RESULTS: Among 74,084 patients identified with CKD and a new prescription for gabapentin or pregabalin, 41% started at >300 or >75 mg/d, respectively. From this set of patients, a weighted study population with a size of 61,367 was generated. Patients who started at a higher dose had a higher 30-day risk of the primary outcome than patients who started at lower dose. Within the weighted population, the numbers of events for higher versus lower dose were 585 of 30,660 (1.9%) versus 462 of 30,707 (1.5%), respectively. The weighted risk ratio was 1.27 (95% CI, 1.13-1.42), and the weighted risk difference was 0.40% (95% CI, 0.21%-0.60%). In subgroup analyses, neither multiplicative nor additive interactions were statistically significant. LIMITATIONS: Residual confounding. CONCLUSIONS: In this population-based study, starting a gabapentinoid at a higher versus a lower dose was associated with a slightly higher risk of a hospital visit with encephalopathy, a fall, or a fracture or hospitalization with respiratory depression. If verified, these risks should be balanced against the benefits of using a higher-dose gabapentinoid.

Initiation Dose of Allopurinol and the Risk of Severe Cutaneous Reactions in Older Adults With CKD: A Population-Based Cohort Study.

RATIONALE & OBJECTIVE: Allopurinol should be started at lower doses in patients with chronic kidney disease (CKD) to avoid adverse effects. We examined the risk of severe cutaneous reactions in older adults with CKD who were newly prescribed allopurinol at varied doses. STUDY DESIGN: Population-based cohort study using linked health care databases. SETTING & PARTICIPANTS: Patients in Ontario, Canada (2008-2019) aged ≥66 years, with an estimated glomerular filtration rate (eGFR) of <60 mL/min/1.73 m2, and who were new users of allopurinol. EXPOSURE: A new prescription for allopurinol >100 mg/d versus a dose ≤100 mg/d. OUTCOME: The primary outcome was a hospital visit with a severe cutaneous reaction within 180 days of starting allopurinol. Secondary outcomes included all-cause hospitalization and all-cause mortality. ANALYTICAL APPROACH: The exposure and referent groups were balanced on indicators of baseline health using inverse probability of treatment weighting on the propensity score. Weighted risk ratios (RR) were obtained using modified Poisson regression and weighted risk differences (RD) using binomial regression. RESULTS: Of 47,315 patients (median age, 76 years; median eGFR, 45 mL/min/1.73 m2), 55% started allopurinol at >100 mg/d. Starting allopurinol at >100 versus ≤100 mg/d was associated with an increased risk of a severe cutaneous reaction: number of events (weighted), 103 of 25,802 (0.40%) versus 46 of 25,816 (0.18%), respectively (weighted RR, 2.25 [95% CI, 1.50-3.37]; weighted RD, 0.22% [95% CI, 0.12%-0.32%]. Starting allopurinol at >100 versus ≤100 mg/d was associated with an increased risk of all-cause hospitalization but not with all-cause mortality. LIMITATIONS: This study was underpowered to detect risk differences in the association of allopurinol dose with outcomes across eGFR categories (ie, 45-59, 30-44, and <30 mL/min/1.73 m2). CONCLUSIONS: Older patients with CKD who started allopurinol at >100 mg/d versus ≤100 mg/d were twice as likely to visit a hospital with a severe cutaneous reaction in the next 180 days.

Baclofen has a risk of encephalopathy in older adults receiving dialysis.

At least 23 case reports link the muscle relaxant baclofen to encephalopathy in patients receiving dialysis. To explore this issue, we conducted a study to quantify the risk of encephalopathy from baclofen in patients receiving dialysis. Linked healthcare databases were used to conduct a population-based cohort study of older adults receiving maintenance dialysis in Ontario, Canada (1997-2018) to compare new users of baclofen to non-users. The primary outcome was the 30-day risk of hospitalization with encephalopathy, defined as a main diagnosis of delirium, disorientation, transient alteration of awareness, or transient cerebral ischemic attack. Inverse probability of treatment weighting on the propensity score was used to balance comparison groups on indicators of baseline health. Weighted risk ratios (RR) were obtained using modified Poisson regression and weighted risk differences (RD) using binomial regression. We studied 360 new baclofen users and 6109 non-users (2638 [41%] women; median age 75). The median baclofen dose was 20 mg/day. Hospitalization with encephalopathy occurred in 26 of 360 baclofen users (7.2%) and in under six of 6109 non-users (under 0.1%); weighted risk ratios, 78.3 (95% confidence interval 27.9 to 219.2); weighted risk differences, 7.1% (4.5% to 9.8%). The median time from baclofen dispensing to hospitalization with encephalopathy was three days. Among patients receiving dialysis, approximately one in 14 were hospitalized with encephalopathy shortly after starting baclofen. Thus, baclofen should be avoided in older adults receiving dialysis, and other muscle relaxants considered in its place. Hence, if baclofen must be used, a low dose should be prescribed, and older adults should be carefully monitored for signs of encephalopathy.

The association of beta-blocker use with mortality in elderly patients with congestive heart failure and advanced chronic kidney disease.

BACKGROUND: Whether the survival benefit of ß-blockers in congestive heart failure (CHF) from randomized trials extends to patients with advanced chronic kidney disease (CKD) [estimated glomerular filtration rate (eGFR) <30 mL/min/1.73 m2 but not receiving dialysis] is uncertain. METHODS: This was a retrospective cohort study using administrative datasets. Older adults from Ontario, Canada, with incident CHF (median age 79 years) from April 2002 to March 2014 were included. We matched new users of ß-blockers to nonusers on age, sex, eGFR categories (>60, 30-60, <30), CHF diagnosis date and a high-dimensional propensity score. Using Cox proportional hazards models, we examined the association of ß-blocker use versus nonuse with all-cause mortality. RESULTS: We matched 5862 incident ß-blocker users (eGFR >60, n = 3136; eGFR 30-60, n = 2368; eGFR <30, n = 358). There were 2361 mortality events during follow-up. ß-Blocker use was associated with reduced all-cause mortality [adjusted hazard ratio (HR) 0.58, 95% confidence interval (CI) 0.54-0.64]. This result was consistent across all eGFR categories (>60: adjusted HR 0.55, 95% CI 0.49-0.62; 30-60: adjusted HR 0.63, 95% CI 0.55-0.71; <30: adjusted HR 0.55, 95% CI 0.41-0.73; interaction term, P = 0.30). The results were consistent in an intention-to-treat analysis and with ß-blocker use treated as a time-varying exposure. CONCLUSIONS: ß-Blocker use is associated with reduced all-cause mortality in elderly patients with CHF and CKD, including those with an eGFR <30. Randomized trials that examine ß-blockers in patients with CHF and advanced CKD are needed.

Nonsteroidal anti-inflammatory drug use and risk of acute kidney injury and hyperkalemia in older adults: a population-based study.

BACKGROUND: Clinical guidelines caution against nonsteroidal anti-inflammatory drug (NSAID) use in older adults. The study objective was to quantify the 30-day risk of acute kidney injury (AKI) and hyperkalemia in older adults after NSAID initiation and to develop a model to predict these outcomes. METHODS: We conducted a population-based retrospective cohort study in Ontario, Canada from 2007 to 2015 of patients ≥66 years. We matched 46 107 new NSAID users with 46 107 nonusers with similar baseline health. The primary outcome was 30-day risk of AKI and secondary outcomes were hyperkalemia and all-cause mortality. RESULTS: NSAID use versus nonuse was associated with a higher 30-day risk of AKI {380 [0.82%] versus 272 [0.59%]; odds ratio (OR) 1.41 [95% confidence interval (CI) 1.20-1.65]} and hyperkalemia [184 (0.40%) versus 123 (0.27%); OR 1.50 (95% CI 1.20-1.89); risk difference 0.23% (95% CI 0.13-0.34)]. There was no association between NSAID use and all-cause mortality. A prediction model incorporated six predictors of AKI or hyperkalemia: older age, male gender, lower baseline estimated glomerular filtration rate, higher baseline serum potassium, angiotensin-converting enzyme inhibitor or angiotensin receptor blocker use or diuretic use. This model had moderate discrimination [C-statistic 0.72 (95% CI 0.70-0.74)] and good calibration. CONCLUSIONS: In older adults, new NSAID use compared with nonuse was associated with a higher 30-day risk of AKI and hyperkalemia but not all-cause mortality. Prescription NSAID use among many older adults may be safe, but providers should use caution and assess individual risk.

The risk of infective endocarditis among people who inject drugs: a retrospective, population-based time series analysis.

BACKGROUND: Infective endocarditis is an increasingly common complication among people who inject drugs. We conducted this study to determine whether the removal of traditional controlled-release oxycodone from the Canadian market would be associated with an increase in the use of hydromorphone and an increased risk of infective endocarditis. METHODS: We conducted a retrospective, population-based time series analysis using the linked health administrative databases of Ontario, Canada. We measured the quarterly risk of admissions for infective endocarditis related to injection drug use and changes in opioid prescription rates from 2006 to 2015. We set the intervention point at the fourth quarter of 2011, when traditional controlled-release oxycodone was removed from the Canadian market. RESULTS: We observed an increase in the risk of admissions for infective endocarditis related to injection drug use during the study period. Before the intervention point, we observed a mean of 13.4 admissions per quarter, and after the intervention, we observed a mean of 35.1 admissions per quarter. However, no significant change in this risk occurred at the intervention point. Rather, the risk of infectious endocarditis appeared to have increased earlier and in parallel with the rise in hydromorphone prescriptions. Hydromorphone represented 16% of all opioid prescriptions at the start of the observation period and 53% by the end. INTERPRETATION: The risk of infective endocarditis related to injection drug use is increasing and is temporally associated with increasing prescriptions for hydromorphone. This relation warrants further exploration.

Risk of rhabdomyolysis with donepezil compared with rivastigmine or galantamine: a population-based cohort study.

BACKGROUND: Donepezil, rivastigmine and galantamine are popular cholinesterase inhibitors used to manage the symptoms of Alzheimer disease and other dementias; regulatory agencies in several countries warn about a possible risk of rhabdomyolysis with donepezil, based on information from case reports. Our goal was to investigate the 30-day risk of admission to hospital with rhabdomyolysis associated with initiating donepezil versus other cholinesterase inhibitors. METHODS: We conducted a retrospective cohort study in Ontario, Canada, from 2002 to 2017. Participants were adults aged 66 years or older with a newly dispensed prescription for donepezil compared with rivastigmine or galantamine. The primary outcome was hospital admission with rhabdomyolysis (assessed using hospital diagnostic codes) within 30 days of a new prescription of a cholinesterase inhibitor. Odds ratios were estimated using logistic regression, with inverse probability of treatment weights calculated from propensity scores. RESULTS: The average age in our 2 groups was 81.1 years, and 61.4% of our population was female. Donepezil was associated with a higher risk of hospital admission with rhabdomyolysis compared with rivastigmine or galantamine (88 events in 152 300 patients [0.06%] v. 16 events in 68 053 patients [0.02%]; weighted odds ratio of 2.21, 95% confidence interval [CI] 1.52-3.22). Most hospital admissions with rhabdomyolysis after donepezil use were not severe, and no patient was treated with acute dialysis or mechanical ventilation. INTERPRETATION: Initiating donepezil is associated with a higher 30-day risk of admission to hospital with rhabdomyolysis compared with initiating rivastigmine or galantamine. The proportion of patients who develop severe rhabdomyolysis within 30 days of initiating donepezil is very low.

Association of Baclofen With Encephalopathy in Patients With Chronic Kidney Disease.

IMPORTANCE: At least 30 case reports have linked the muscle relaxant baclofen to encephalopathy in patients with chronic kidney disease (CKD). OBJECTIVE: To compare the 30-day risk of encephalopathy in patients with CKD and newly prescribed baclofen at greater than or equal to 20 mg per day vs less than 20 mg per day. The secondary objective was to compare the risk of encephalopathy in baclofen users vs nonusers. DESIGN, SETTING, AND PARTICIPANTS: Retrospective population-based cohort study in Ontario, Canada (2007-2018) using linked health care data. Participants comprised 15 942 older adults (aged 66 years or older) with CKD (defined as an estimated glomerular filtration rate [eGFR] <60 mL/min/1.73 m2 but not receiving dialysis). The primary cohort was restricted to patients who were newly prescribed baclofen; participants in the secondary cohort were new users and nonusers. EXPOSURES: Prescription for oral baclofen greater than or equal to 20 mg per day vs less than 20 mg per day. MAIN OUTCOMES AND MEASURES: Hospital admission with encephalopathy, defined as a main diagnosis of delirium, disorientation, transient alteration of awareness, transient cerebral ischemic attack, or unspecified dementia within 30 days of starting baclofen. Inverse probability of treatment weighting on the propensity score was used to balance comparison groups on indicators of baseline health. Weighted risk ratios (RRs) were obtained using modified Poisson regression and weighted risk differences (RDs) using binomial regression. Prespecified subgroup analyses were conducted by eGFR category. RESULTS: The primary cohort comprised 15 942 patients with CKD (9699 [61%] women; median age, 77 years [interquartile range, 71-82]; 9707 [61%] patients started baclofen at ≥20 mg/d and 6235 [39%] at <20 mg/d). The primary outcome, hospitalization with encephalopathy, occurred in 108/9707 (1.11%) patients who started baclofen at greater than or equal to 20 mg per day and in 26/6235 (0.42%) who started baclofen at less than 20 mg per day; weighted RR, 3.54 (95% CI, 2.24 to 5.59); weighted RD, 0.80% (95% CI, 0.55% to 1.04%). In subgroup analysis, the absolute risk increased progressively at lower eGFR (weighted RD eGFR 45-59, 0.42% [95% CI, 0.19%-0.64%]; eGFR 30-44, 1.23% [95% CI, 0.62%-1.84%]; eGFR <30, 2.90% [95% CI, 1.30%-4.49%]; P for interaction, <.001]). In the secondary comparison with 284 263 nonusers, both groups of baclofen users had a higher risk of encephalopathy (<20 mg/d weighted RR, 5.90 [95% CI, 3.59 to 9.70] and ≥20 mg/d weighted RR, 19.8 [95% CI, 14.0 to 28.0]). CONCLUSIONS AND RELEVANCE: Among older patients with CKD who were newly prescribed baclofen, the 30-day incidence of encephalopathy was increased among those prescribed higher doses compared with lower doses. If verified, these risks should be balanced against the benefits of baclofen use.

Validation of an Algorithm to Identify Infective Endocarditis in People Who Inject Drugs.

INTRODUCTION: Infective endocarditis is associated with high morbidity and mortality. Currently, there is concern that the incidence of infective endocarditis associated with people who inject drugs (PWID) is increasing. However, it is difficult to monitor population-wide trends in PWID-associated infective endocarditis, as there is no International Statistical Classification of Diseases, 10th Revision (ICD-10) code for injection drug use. To address this barrier, we sought to develop a validated algorithm using ICD-10 discharge diagnosis codes. MATERIALS AND METHODS: We constructed a cohort of patients whose hospital discharge diagnosis included infective endocarditis. We reviewed 100 patients with incident infective endocarditis from 2014 to 2016 for their infective endocarditis and injection drug use status. We calculated the operating characteristics for algorithms constructed using permutations of ICD-10 codes associated with injection drug use. We repeated this analysis in a cohort of 100 patients with incident infective endocarditis from 2009 to 2011 to examine the temporal stability of the operating characteristics of each algorithm. RESULTS: We found that a combination of hepatitis C virus, drug use, and mental/behavioral disorder codes yielded the highest sensitivity (93%) and positive predictive value (83%) of the algorithms analyzed. DISCUSSION: We have described the first algorithm, validated against chart review data, for identifying PWID-associated infective endocarditis cases using ICD-10 codes. The high sensitivity and positive predictive value indicate that this algorithm can be used for surveillance and research with confidence. CONCLUSIONS: This algorithm will enable researchers to examine epidemiological trends in PWID-associated infective endocarditis.

Beta blockers in patients with end-stage renal disease-Evidence-based recommendations.

For patients who require hemodialysis, beta blockers offer a simultaneous opportunity and challenge in the treatment of cardiovascular disease. Beta blockers are well supported by data from nondialysis populations and directly mitigate the sympathetic overactivity that links chronic kidney disease with cardiovascular sequelae. However, the evidence supporting their use in patients receiving hemodialysis is sparse and the heterogeneity of the beta blocker class makes it difficult to prescribe these medications with confidence. Despite these limitations, both trial and observational data exist that can help guide the use of these medications. In this review, we outline the reasons to consider beta blockers for patients receiving hemodialysis, discuss the barriers to their use, and provide specific evidence-based recommendations for beta blocker use in patients with heart failure, hypertension, ischemic heart disease and arrhythmia.

Effect of Coaching to Increase Water Intake on Kidney Function Decline in Adults With Chronic Kidney Disease: The CKD WIT Randomized Clinical Trial.

Importance: In observational studies, increased water intake is associated with better kidney function. Objective: To determine the effect of coaching to increase water intake on kidney function in adults with chronic kidney disease. Design, Setting, and Participants: The CKD WIT (Chronic Kidney Disease Water Intake Trial) randomized clinical trial was conducted in 9 centers in Ontario, Canada, from 2013 until 2017 (last day of follow-up, May 25, 2017). Patients had stage 3 chronic kidney disease (estimated glomerular filtration rate [eGFR] 30-60 mL/min/1.73 m2 and microalbuminuria or macroalbuminuria) and a 24-hour urine volume of less than 3.0 L. Interventions: Patients in the hydration group (n = 316) were coached to drink more water, and those in the control group (n = 315) were coached to maintain usual intake. Main Outcomes and Measures: The primary outcome was change in kidney function (eGFR from baseline to 12 months). Secondary outcomes included 1-year change in plasma copeptin concentration, creatinine clearance, 24-hour urine albumin, and patient-reported overall quality of health (0 [worst possible] to 10 [best possible]). Results: Of 631 randomized patients (mean age, 65.0 years; men, 63.4%; mean eGFR, 43 mL/min/1.73 m2; median urine albumin, 123 mg/d), 12 died (hydration group [n = 5]; control group [n = 7]). Among 590 survivors with 1-year follow-up measurements (95% of 619), the mean change in 24-hour urine volume was 0.6 L per day higher in the hydration group (95% CI, 0.5 to 0.7; P < .001). The mean change in eGFR was -2.2 mL/min/1.73 m2 in the hydration group and -1.9 mL/min/1.73 m2 in the control group (adjusted between-group difference, -0.3 mL/min/1.73 m2 [95% CI, -1.8 to 1.2; P = .74]). The mean between-group differences (hydration vs control) in secondary outcomes were as follows: plasma copeptin, -2.2 pmol/L (95% CI, -3.9 to -0.5; P = .01); creatinine clearance, 3.6 mL/min/1.73 m2 (95% CI, 0.8 to 6.4; P = .01); urine albumin, 7 mg per day (95% CI, -4 to 51; P = .11); and quality of health, 0.2 points (95% CI, -0.3 to 0.3; P = .22). Conclusions and Relevance: Among adults with chronic kidney disease, coaching to increase water intake compared with coaching to maintain the same water intake did not significantly slow the decline in kidney function after 1 year. However, the study may have been underpowered to detect a clinically important difference. Trial Registration: clinicaltrials.gov Identifier: NCT01766687.

Advances in the management of hyperkalemia in chronic kidney disease.

PURPOSE OF REVIEW: Patients with chronic kidney disease (CKD) have an increased risk of hyperkalemia that increases both short-term and long-term mortality. Historically, managing hyperkalemia has relied upon dietary modifications, augmentation of urinary potassium excretion and enhanced enteral potassium elimination. This review discusses current treatments and their limitations and summarizes the evidence supporting novel agents for potassium lowering in patients with CKD. RECENT FINDINGS: The introduction of two novel ion exchange resins represents the first new pharmacologic therapies for hyperkalemia in the last 50 years. Patiromer, which was recently approved for use in the United States, has been shown to be well tolerated and effective for decreasing serum potassium in patients with CKD when taken for up to a year. Sodium zirconium cyclosilicate for which approval is pending has also shown promise in treating both acute and chronic hyperkalemia in patients with CKD. Both medications have been well tolerated with minimal adverse events in relatively short-term follow-up. SUMMARY: Novel ion exchange resins have the potential to provide new strategies for safely and effectively managing hyperkalemia in the CKD population. This may decrease morbidity and mortality associated with hyperkalemia and allow more broad use of medications whose use is otherwise limited by hyperkalemia.

Second-Generation Antidepressants and Hyponatremia Risk: A Population-Based Cohort Study of Older Adults.

BACKGROUND: Hyponatremia may occur after initiation of a second-generation antidepressant drug. However, the magnitude of this risk among older adults in routine care is not well characterized. STUDY DESIGN: Retrospective, population-based, matched-cohort study. SETTING & PARTICIPANTS: In Ontario, Canada, 2003 to 2012, we compared older adults with a mood or anxiety disorder who were dispensed 1 of 9 second-generation antidepressant drugs with matched adults with comparable indicators of baseline health who were not dispensed an antidepressant drug (n=138,246 per group). A similar comparison was made in a subpopulation with available laboratory data (n=4,186 per group). PREDICTOR: Second-generation antidepressant prescription versus no antidepressant prescription. OUTCOMES: The primary outcome was hospitalization with hyponatremia. A secondary outcome was hospitalization with both hyponatremia and delirium. MEASUREMENTS: We assessed hospitalization with hyponatremia using a diagnosis code and, in the subpopulation, serum sodium values. We assessed hospitalization with hyponatremia and delirium using a combination of diagnosis codes. RESULTS: Second-generation antidepressant use versus nonuse was associated with higher 30-day risk for hospitalization with hyponatremia (450/138,246 [0.33%] vs 84/138,246 [0.06%]; relative risk [RR], 5.46 [95% CI, 4.32-6.91]). This association was consistent in the subpopulation with serum sodium values (73/4,186 [1.74%] vs 18/4,186 [0.43%]; RR, 4.23 [95% CI, 2.50-7.19]; absolute risk increase, 1.31% [95% CI, 0.87%-1.75%]). Second-generation antidepressant use versus nonuse was also associated with higher 30-day risk for hospitalization with both hyponatremia and delirium (28/138,246 [0.02%] vs 7/138,246 [0.005%]; RR, 4.00 [95% CI, 1.75-9.16]). LIMITATIONS: Measures of serum sodium could be ascertained in only a subpopulation. CONCLUSIONS: Use of a second-generation antidepressant in routine care by older adults is associated with an approximate 5-fold increase in 30-day risk for hospitalization with hyponatremia compared to nonuse. However, the absolute increase in 30-day incidence is low.

Clearance of cardiovascular medications during hemodialysis.

PURPOSE OF REVIEW: To review the current understanding of hemodialysis-mediated clearance of commonly used cardiovascular medications. RECENT FINDINGS: Although cardiovascular drug dialyzability is poorly understood, many drug classes appear to include agents with substantially different degrees of dialyzability. Recent data suggest that more readily dialyzable beta-blockers associate with higher short-term mortality in patients initiating these drugs when on hemodialysis. Although this relationship was not observed in a later study with angiotensin-converting enzyme inhibitors of varying dialyzability, studies of this kind are currently limited by pharmacokinetic data that are either incomplete or no longer applicable to modern hemodialysis procedures. SUMMARY: There are substantial deficits in our understanding of cardiovascular medication dialyzability, which relates in large part to advances in the process of hemodialysis that have rendered older studies of dialyzability irrelevant. The importance of cardiovascular disease in patients receiving hemodialysis demands a better understanding of the effect hemodialysis exerts on cardiovascular drug pharmacokinetics.

Antiepileptic drugs and hyponatremia in older adults: Two population-based cohort studies.

OBJECTIVE: To examine the 30-day risk of hospitalization with hyponatremia associated with carbamazepine, valproic acid (V), phenytoin (P), or topiramate (T) use compared to nonuse in the outpatient setting among older adults. METHODS: We conducted two population-based, retrospective cohort studies in Ontario, Canada, between 2003 and 2015 using administrative health care databases of older adults. The first study compared carbamazepine users to a propensity-score matched group of antiepileptic drug nonusers, whereas the second compared V-P-T users to a propensity-score matched group of antiepileptic nonusers. The primary outcome was hospitalization with hyponatremia within 30 days of an antiepileptic prescription. RESULTS: The baseline characteristics between matched groups were similar in both cohorts. Carbamazepine use versus nonuse was associated with a higher 30-day risk of hospitalization with hyponatremia (82/21,191 [0.39%] versus 30/63,573 [0.05%]; relative risk [RR] 8.20, 95% confidence interval [CI] 5.40-12.46). Similarly, V-P-T use versus nonuse was associated with a higher 30-day risk of hospitalization with hyponatremia (34/20,155 [0.17%] versus 26/40,310 [0.06%]; RR 2.62, 95% CI 1.57-4.36). SIGNIFICANCE: Older adults prescribed carbamazepine and V-P-T have a higher risk of being hospitalized with hyponatremia compared to other adults with similar indicators of baseline health who were not prescribed antiepileptic drugs. Physicians should be mindful of this risk; when a patient presents to a hospital with symptomatic hyponatremia these drugs should be considered as potential causes.

ß-Blocker dialyzability and mortality in older patients receiving hemodialysis.

Some ß-blockers are efficiently removed from the circulation by hemodialysis ("high dialyzability") whereas others are not ("low dialyzability"). This characteristic may influence the effectiveness of the ß-blockers among patients receiving long-term hemodialysis. To determine whether new use of a high-dialyzability ß-blocker compared with a low-dialyzability ß-blocker associates with a higher rate of mortality in patients older than age 66 years receiving long-term hemodialysis, we conducted a propensity-matched population-based retrospective cohort study using the linked healthcare databases of Ontario, Canada. The high-dialyzability group (n=3294) included patients initiating atenolol, acebutolol, or metoprolol. The low-dialyzability group (n=3294) included patients initiating bisoprolol or propranolol. Initiation of a high- versus low-dialyzability ß-blocker was associated with a higher risk of death in the following 180 days (relative risk, 1.4; 95% confidence interval, 1.1 to 1.8; P<0.01). Supporting this finding, we repeated the primary analysis in a cohort of patients not receiving hemodialysis and found no significant association between dialyzability and the risk of death (relative risk, 1.0; 95% confidence interval, 0.9 to 1.3; P=0.71). ß-Blocker exposure was not randomly allocated in this study, so a causal relationship between dialyzability and mortality cannot be determined. However, our findings should raise awareness of this potentially important drug characteristic and prompt further study.