Trimethoprim-sulfamethoxazole induced hyperkalaemia in elderly patients receiving spironolactone: nested case-control study

Hyperkalemic effect of drug-drug interaction between esaxerenone and trimethoprim in patients with hypertension: a pilot study

BACKGROUND

We examined whether the pharmacodynamic drug-drug interaction between esaxerenone and trimethoprim enhances the hyperkalemic effect.

METHODS

A retrospective observational study was conducted to identify patients >18 years undertaking esaxerenone alone or esaxerenone plus trimethoprim at Mie University Hospital from May 2019 to December 2022. We performed propensity score-matching (1:1) to compare between-group differences in the maximum change in serum potassium levels (ΔK) using the Mann-Whitney U test. For esaxerenone plus trimethoprim, Spearman's correlation coefficients were used to examine correlations between ΔK and variables, including changes in blood urea nitrogen (ΔBUN), serum creatinine levels (ΔCr), and weekly trimethoprim cumulative dose.

RESULTS

Out of propensity score-matched groups (n=8 each), serum potassium levels significantly increased after administration of esaxerenone alone (4.4 [4.2 to 4.7] meq/L to 5.2 [4.7 to 5.4] meq/L, p=0.008) and esaxerenone plus trimethoprim (4.2 [4.0 to 5.1] meq/L to 5.4 [4.7 to 5.5] meq/L, p=0.023). ΔK did not significantly differ between the groups (esaxerenone alone; 0.6 [0.3 to 0.9] meq/L vs. esaxerenone plus trimethoprim; 1.0 [0.4 to 1.3] meq/L, p=0.342). ΔK positively correlated with ΔBUN (r=0.988, p<0.001) or ΔCr (r=0.800, p=0.017). There was a trend of correlation of ΔK with a weekly cumulative trimethoprim dose (r=0.607, p=0.110).

CONCLUSIONS

The hyperkalemic effect of the drug-drug interaction between esaxerenone and trimethoprim is not notable and related to renal function and trimethoprim dosage.

Sulfamethoxazole-Trimethoprim-Induced Hyperkalemia in Hospitalized Patients Using Potassium-Sparing Drugs: An Observational Study

The objective of this analysis is to investigate the risk of hyperkalemia in hospitalized patients using sulfamethoxazole-trimethoprim (Co-trimoxazole) and a potassium-sparing drug (potassium-sparing diuretic or renin-angiotensin system [RAS]-inhibitor). Researchers conducted a nested case control study within a cohort of hospitalized patients using a potassium-sparing diuretic and/or a RAS-inhibitor from the PHARMO Database Network. Researchers estimated the odds ratios (ORs) and 95% confidence intervals (CI) for the risk of hyperkalemia in patients receiving both Co-trimoxazole and a potassium-sparing drug compared with patients only receiving a potassium-sparing drug. Among a cohort of 25,849 patients, researchers identified 2054 cases of hyperkalemia during hospitalization in patients also using a potassium-sparing drug. Using Co-trimoxazole in addition to a potassium-sparing drug was associated with an increased risk of hyperkalemia in hospitalized patients (ORadj = 1.65, 95% CI 1.26-2.16) compared with using only a potassium-sparing drug. There was a trend of a more pronounced association between hyperkalemia and the co-use of Co-trimoxazole and potassium-sparing drugs in patients with an estimated GFR of 15-29 mL/min (ORadj = 3.15, 95% CI 1.29-7.70). The number needed to harm for hyperkalemia induced by adding Co-trimoxazole to patients receiving a potassium-sparing drug is 19.5. Using the combination of Co-trimoxazole with a potassium-sparing drug in hospitalized patients increases the risk of hyperkalemia compared with using only a potassium-sparing drug. Physicians and other prescribers should be aware of hyperkalemia and routinely monitor serum potassium levels in hospitalized patients using this combination of drugs.

Drug-drug interactions between gender-affirming hormone therapy and antiretrovirals for treatment/prevention of HIV

Transgender persons face a greater burden of HIV compared to cisgender counterparts. Concerns around drug-drug interactions (DDIs) have been cited as reasons for lower engagement in HIV care and lower pre-exposure prophylaxis (PrEP) uptake among transgender populations. It is therefore imperative for hormone therapy, PrEP and antiretroviral therapy providers to understand the DDI potential between these therapies. Studies of tenofovir disoproxil fumarate (TDF)/emtricitabine (FTC) PrEP with feminizing hormone therapies (FHTs) show reduced plasma tenofovir concentrations, but intracellular concentrations of tenofovir-diphosphate are not reduced. Efficacy of PrEP is expected to be maintained despite this interaction. Masculinizing hormone therapies have no effect on tenofovir concentrations but may increase FTC to a nonclinically relevant extent. No interactions between FHT and cabotegravir or tenofovir alafenamide have been demonstrated. Administration of TDF/FTC PrEP has no effect on hormone levels in transmen or transwomen. PrEP is expected to be effective and safe in transpersons and should be provided to high-risk individuals regardless of gender affirming hormone use. Enzyme inducing/inhibiting antiretroviral therapy may decrease or increase, respectively, the concentrations of FHT and masculinizing hormone therapy. Unboosted integrase inhibitors or enzyme neutral non-nucleoside reverse transcriptase inhibitors are not expected to affect and are not affected by gender affirming hormones and can be considered in transmen and transwomen. Overlapping toxicities including weight gain, dyslipidaemia, cardiovascular disease and bone density effects should be considered, and antiretroviral modifications can be made to minimize toxicities. Interactions between supportive care medications should be assessed to avoid chelation interactions and hyperkalaemia.

Pharmacotherapeutic Considerations in the Treatment of Nontuberculous Mycobacterial Infections: A Primer for Clinicians

Nontuberculous mycobacteria (NTM) can cause a variety of infections, including serious pulmonary disease. Treatment encompasses polypharmacy, with a targeted regimen of 2-5 active medications, depending on site of infection, species, and clinical characteristics. Medications may include oral, intravenous, and inhalational routes. Medication acquisition can be challenging for numerous reasons, including investigational status, limited distribution models, and insurance prior authorization. Additionally, monitoring and managing adverse reactions and drug interactions is a unique skill set. While NTM is primarily medically managed, clinicians may not be familiar with the intricacies of medication selection, procurement, and monitoring. This review offers insights into the pharmacotherapeutic considerations of this highly complex disease state, including regimen design, medication acquisition, safety monitoring, relevant drug-drug interactions, and adverse drug reactions.

New Persistent Opioid Use After Childbirth

OBJECTIVE

To examine factors associated with new persistent opioid use after childbirth.

METHODS

We conducted a population-based cohort study of individuals who initiated opioid therapy within 7 days of discharge from hospital after delivery between September 1, 2013, and September 30, 2021. The primary outcome was new persistent opioid use , which was defined as one or more prescriptions for an opioid within 90 days of the first postpartum prescription and one or more subsequent opioid prescriptions in the 91-365 days afterward. We used multivariable logistic regression to assess patient-, pregnancy-, and prescription-related factors associated with new persistent opioid use after delivery.

RESULTS

We identified 118,694 unique deliveries after which opioids were initiated, including 99,399 cesarean (83.7%) and 19,295 vaginal (16.3%) deliveries. Among mothers who initiated an opioid after delivery, 1,282 (10.8/1,000 deliveries) met our definition of new persistent opioid use in the subsequent year. Rates of new persistent opioid use were appreciably higher after vaginal (16.0/1,000) compared with cesarean (9.8/1,000) deliveries. Each additional 30 morphine milligram equivalents in the initial opioid prescription was associated with an increased risk of new persistent use after cesarean (adjusted odds ratio [aOR] 1.06, 95% CI 1.04-1.08) and vaginal (aOR 1.05, 95% CI 1.02-1.08) delivery. A concomitant benzodiazepine prescription after cesarean delivery was associated with a markedly increased risk of persistent opioid use (aOR 2.69, 95% CI 1.60-4.52).

CONCLUSION

Among people who filled an opioid prescription after delivery, about 1% displayed evidence of persistent opioid use in the subsequent year. Initial prescriptions for large quantities of opioids and a concurrent benzodiazepine prescription may be important modifiable risk factors to prevent new persistent opioid use after delivery.

Impact of thrice-weekly cotrimoxazole prophylaxis on creatinine and potassium plasma levels in kidney transplant recipients

INTRODUCTION

Cotrimoxazole (CTX) 800/160 mg daily or thrice-weekly is recommended as prophylaxis of Pneumocystis jirovecii pneumonia in kidney transplant recipients. Cotrimoxazole 800/160 daily elevates plasma creatinine and potassium levels but whether the thrice-weekly regimen does so is unknown.

METHODS

Medical records of 225 kidney transplant recipients at Cliniques Universitaires Saint-Luc were analyzed retrospectively. All received thrice-weekly CTX 800/160 for 6 months after transplantation. Monthly laboratory results, co-medications, and tacrolimus trough levels were compared. Standard statistical tests were used.

RESULTS

One month after CTX stop, creatinine level decreased by 0.11 mg/dl (8%, p = 0.029). This contrasts with its stability in previous and subsequent months. No co-medication change accounted for this decrease. The decrease averaged 0.17 mg/dl (p < 0.01) in the highest initial creatinine tertile. The higher the initial creatinine level, the greater the decrease after CTX stop (p < 0.001), and urea levels remained stable after CTX stop. Potassium levels decreased by 0.09 mmol/L (p = 0.021) one month after CTX stop, and decreased by 0.23 mmol/L (p < 0.01) in the highest initial potassium level tertile.

CONCLUSIONS

Our study pinpoints the impact of CTX 800/160 thrice-weekly on creatinine and potassium levels in kidney transplant recipients. This should be considered when interpreting the evolution of plasma creatinine over time, especially in patients with graft dysfunction. Thus, creatinine levels of cohorts with 6 months versus lifelong CTX require different interpretations.

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.

Highly versus less bioavailable oral antibiotics in the treatment of gram-negative bloodstream infections: a propensity-matched cohort analysis

OBJECTIVES

In this study, we evaluated the clinical outcomes associated with the use of highly bioavailable oral antibiotics (fluoroquinolones and trimethoprim-sulfamethoxazole) compared with the less-bioavailable oral antibiotics (β-lactams) in gram-negative bloodstream infections (BSIs).

METHODS

Among hospitalized older adult patients in Ontario, Canada, discharged home on oral treatment for gram-negative BSI between 1 January 2017 and 31 December 2019, we used a matched cohort design to compare outcomes among those receiving highly versus less-bioavailable agents; hard-matching 1:1 on sex, BSI pathogen (Escherichia coli vs. non-E. coli), and infection source (urinary vs. non-urinary/unknown source) along with a propensity score, incorporating specific pathogen, patient, and infection characteristics. The primary outcome was the composite of 90-day all-cause mortality, recurrent BSI with the same pathogen (genus and species), and re-admission to any Ontario hospital.

RESULTS

A total of 2012 patients were included in the study (1006 in each bioavailability category). Those who received highly (compared with less) bioavailable antibiotics at discharge had lower rates of the composite outcome (171/1006 [17.0%] vs. 216/1006 [21.5%]), adjusted odds ratio being 0.74 (95% CI, 0.60-0.92). Recurrent BSI at 90 days was the main driver for the composite outcome occurring in 64 (5.4%) and 107 (9.4%) patients of the highly and less-bioavailable groups, respectively (p < 0.001) (adjusted odds ratio, 0.56; 95% CI, 0.40-0.78).

DISCUSSION

Use of highly (compared with less) bioavailable antibiotics at discharge was associated with significantly better clinical outcomes among patients with gram-negative BSIs.

Maternal opioid treatment after delivery and risk of adverse infant outcomes: population based cohort study

OBJECTIVE

To examine whether maternal opioid treatment after delivery is associated with an increased risk of adverse infant outcomes.

DESIGN

Population based cohort study.

SETTING

Ontario, Canada.

PARTICIPANTS

865 691 mother-infant pairs discharged from hospital alive within seven days of delivery from 1 September 2012 to 31 March 2020. Each mother who filled an opioid prescription within seven days of discharge was propensity score matched to a mother who did not.

MAIN OUTCOME MEASURES

The primary outcome was hospital readmission of infants for any reason within 30 days of their mother filling an opioid prescription (index date). Infant related secondary outcomes were any emergency department visit, hospital admission for all cause injury, admission to a neonatal intensive care unit, admission with resuscitation or assisted ventilation, and all cause death.

RESULTS

85 675 mothers (99.8% of the 85 852 mothers prescribed an opioid) who filled an opioid prescription within seven days of discharge after delivery were propensity score matched to 85 675 mothers who did not. Of the infants admitted to hospital within 30 days, 2962 (3.5%) were born to mothers who filled an opioid prescription compared with 3038 (3.5%) born to mothers who did not. Infants of mothers who were prescribed an opioid were no more likely to be admitted to hospital for any reason than infants of mothers who were not prescribed an opioid (hazard ratio 0.98, 95% confidence interval 0.93 to 1.03) and marginally more likely to be taken to an emergency department in the subsequent 30 days (1.04, 1.01 to 1.08), but no differences were found for any other adverse infant outcomes and there were no infant deaths.

CONCLUSIONS

Findings from this study suggest no association between maternal opioid prescription after delivery and adverse infant outcomes, including death.

Severe hyponatremia due to trimethoprim-sulfamethoxazole-induced SIADH

Hyponatremia, a serum sodium level of <135 mEq/L, is the most common electrolyte abnormality occurring in 5%–35% of hospitalized patients. It is a predictor of increased morbidity and mortality. Diuretics, psychotropic, and antiepileptic drugs are commonly implicated in drug-induced hyponatremia. Trimethoprim-sulfamethoxazole and spironolactone are two commonly prescribed drugs; unfortunately, most providers are unfamiliar with these two drugs causing hyponatremia. Simultaneous use of trimethoprim-sulfamethoxazole and spironolactone can cause serious drug interactions that increase the risk of hyponatremia, hyperkalemia, and overall mortality. Despite recommendations to avoid using these two drugs concurrently, many healthcare providers continue to prescribe them together. We report a case of an elderly female with severe hyponatremia caused by trimethoprim-sulfamethoxazole superimposed on a chronic but stable mild hyponatremia.

Trimethoprim-associated hyperkalaemia: a systematic review and meta-analysis

INTRODUCTION

Trimethoprim is structurally similar to potassium-sparing diuretics and may induce hyperkalaemia. The prevalence and the factors that predispose to trimethoprim-associated hyperkalaemia have never been extensively addressed.

METHODS

A literature search with no date or language limits was carried out using the National Library of Medicine, Embase and Web of Science in March and repeated during August 2021. The principles underlying the Economic and Social Research Council guidance on the conduct of synthesis and the PRISMA guidelines were employed. For the analysis, we retained reports including ≥10 subjects on treatment with trimethoprim, which addressed the possible occurrence of hyperkalaemia.

RESULTS

Eighteen reports were retained for the final analysis. The pooled prevalence of potassium value >5.0 mmol/L, >5.5 mmol/L and >6.0 mmol/L or symptomatic, was, respectively, 22%, 10% and 0.2%. The analysis disclosed that the risk of trimethoprim-associated hyperkalaemia is dose-related and enhanced by drugs with known hyperkalaemic potential including potassium-sparing diuretics, renin-angiotensin-aldosterone system inhibitors, β-blockers and non-steroidal anti-inflammatory agents. Poor kidney function also increased the tendency towards hyperkalaemia. The time to onset of hyperkalaemia was generally 1 week or less after starting trimethoprim.

CONCLUSIONS

The present analysis documents the hyperkalaemic potential of trimethoprim, a widely prescribed drug that was introduced more than 50 years ago. Clinicians must recognize patients at risk of trimethoprim-associated hyperkalaemia.

Prevalence and risk factors of trimethoprim/sulfamethoxazole-related acute kidney injury in pediatric patients: an observational study from a public database

BACKGROUND

Trimethoprim/sulfamethoxazole (TMP/SMZ) is widely used in various clinical settings. Studies have revealed that it may cause acute kidney injury (AKI) in adults. However, the correlation between the use of TMP/SMZ and renal injury in pediatric patients is still unclear. This study aimed to identify the impact of TMP/SMZ on the occurrence of AKI in children.

METHODS

A retrospective observational study was conducted using data of patients treated with TMP/SMZ from the Paediatric Intensive Care clinical database. A newly developed criterion was used for the diagnosis of AKI, and univariate and multiple logistic regression analyses were performed to identify the risk factors of TMP/SMZ-related renal injury.

RESULTS

A total of 113 patients were included. The prevalence of AKI was 21.2% (24/113). Univariate analysis indicated that the AKI group showed significantly higher baseline serum creatinine level (46.00 vs. 37.00 µmol/L; P=0.034) and in-hospital mortality rate [29.2% (7/24) vs. 9.0% (8/89); P=0.01] than that of the non-AKI group. Multivariate analysis revealed that the occurrence of AKI was significantly associated with increased baseline serum creatinine level [odds ratio (OR) =1.029; 95% CI: 1.006-1.053; P=0.014] and concurrent use of vancomycin (OR =5.349; 95% CI: 1.381-20.714; P=0.015). A proportion of 79.2% of patients (19/24) developed AKI within the first 10 days of TMP/SMZ use.

CONCLUSIONS

Elevated baseline serum creatinine level (≥40.25 µmol/L) and concurrent use of vancomycin were associated with the development of AKI in young patients. Further large multi-center prospective studies are necessary to confirm these relationships and validate their clinical significance.

Low-dose trimethoprim-sulfamethoxazole for the treatment of Pneumocystis jirovecii pneumonia (LOW-TMP): protocol for a phase III randomised, placebo-controlled, dose-comparison trial

INTRODUCTION

Pneumocystis jirovecii pneumonia (PJP) is an opportunistic infection of immunocompromised hosts with significant morbidity and mortality. The current standard of care, trimethoprim-sulfamethoxazole (TMP-SMX) at a dose of 15-20 mg/kg/day, is associated with serious adverse drug events (ADE) in 20%-60% of patients. ADEs include hypersensitivity reactions, drug-induced liver injury, cytopenias and renal failure, all of which can be treatment limiting. In a recent meta-analysis of observational studies, reduced dose TMP-SMX for the treatment of PJP was associated with fewer ADEs, without increased mortality.

METHODS AND ANALYSIS

A phase III randomised, placebo-controlled, trial to directly compare the efficacy and safety of low-dose TMP-SMX (10 mg/kg/day of TMP) with the standard of care (15 mg/kg/day of TMP) among patients with PJP, for a composite primary outcome of change of treatment, new mechanical ventilation, or death. The trial will be undertaken at 16 Canadian hospitals. Data will be analysed as intention to treat. Primary and secondary outcomes will be compared using logistic regression adjusting for stratification and presented with 95% CI.

ETHICS AND DISSEMINATION

This study has been conditionally approved by the McGill University Health Centre; Ethics approval will be obtained from all participating centres. Results will be submitted for publication in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT04851015.

Longitudinal Data Discontinuity in Electronic Health Records and Consequences for Medication Effectiveness Studies

Electronic health record (EHR) discontinuity (i.e., receiving care outside of the study EHR system), can lead to information bias in EHR-based real-world evidence (RWE) studies. An algorithm has been previously developed to identify patients with high EHR-continuity. We sought to assess whether applying this algorithm to patient selection for inclusion can reduce bias caused by data-discontinuity in four RWE examples. Among Medicare beneficiaries aged >=65 years from 2007 to 2014, we established 4 cohorts assessing drug effects on short-term or long-term outcomes, respectively. We linked claims data with two US EHR systems and calculated %bias of the multivariable-adjusted effect estimates based on only EHR vs. linked EHR-claims data because the linked data capture medical information recorded outside of the study EHR. Our study cohort included 77,288 patients in system 1 and 60,309 in system 2. We found the subcohort in the lowest quartile of EHR-continuity captured 72-81% of the short-term and only 21-31% of the long-term outcome events, leading to %bias of 6-99% for the short-term and 62-112% for the long-term outcome examples. This trend appeared to be more pronounced in the example using a nonuser comparison rather than an active comparison. We did not find significant treatment effect heterogeneity by EHR-continuity for most subgroups across empirical examples. In EHR-based RWE studies, investigators may consider excluding patients with low algorithm-predicted EHR-continuity as the EHR data capture relatively few of their actual outcomes, and treatment effect estimates in these patients may be unreliable.

Southern African HIV Clinicians' Society gender-affirming healthcare guideline for South Africa

No abstract available.

Single-Center Retrospective Analysis of Prophylaxis and Treatment of Pneumocystis carinii Pneumonia in Patients with Renal Dysfunction After Renal Transplantation

BACKGROUND Pneumocystis carinii is an opportunistic pathogen that can cause severe lung infections after renal transplantation. Trimethoprim-sulfamethoxazole (TMP-SMX) has been recognized as a first-line treatment for chemoprophylaxis of Pneumocystis carinii pneumonia (PCP). This study aimed to establish a personalized chemoprophylaxis prescription specifically for those recipients with renal insufficiency. MATERIAL AND METHODS This retrospective study included 68 patients with confirmed PCP after renal transplantation. Patients were divided into 2 groups: an abnormal renal function (ARF) group (creatinine ≥1.5 ng/dl; n=37) and a normal renal function (NRF) group (creatinine <1.5 ng/dl; n=31). Clinical characteristics and prognosis of PCP in both groups were compared and analyzed. RESULTS Patients in the ARF group had more prophylaxis after transplantation (15 [40.5%] vs. 2 [6.5%], p=0.047), had more biopsy-proven rejections (10 [27%] vs. 1 [3.2%], p=0.008), and had lower lymphocyte counts (0.6 [05-0.9] vs. 1.1 [0.7-1.6], p<0.01). Renal function after treatment was obviously improved in the ARF group, which had a significant decrease rate in creatinine (-13.2% [-22~4.8%] vs. -4.4% [-12.6~20.9%], p=0.043). CONCLUSIONS PCP prophylaxis regimens for recipients after renal transplantation are still needed regardless of whether the renal functions were normal or abnormal, especially for recipients with persistent lymphopenia or rejection after transplantation.

Heart Failure: A Palliative Medicine Review of Disease, Therapies, and Medications With a Focus on Symptoms, Function, and Quality of Life

Despite significant advances in heart failure (HF) treatment, HF remains a progressive, extremely symptomatic, and terminal disease with a median survival of 2.1 years after diagnosis. HF often leads to a constellation of symptoms, including dyspnea, fatigue, depression, anxiety, insomnia, pain, and worsened cognitive function. Palliative care is an approach that improves the quality of life of patients and their caregivers facing the problems associated with life-threatening illness and therefore is well suited to support these patients. However, historically, palliative care has often focused on supporting patients with malignant disease, rather than a progressive chronic disease such as HF. Predicting mortality in patients with HF is challenging. The lack of obvious transition points in disease progression also raises challenges to primary care providers and specialists to know at what point to integrate palliative care during a patient's disease trajectory. Although therapies for HF often result in functional and symptomatic improvements including health-related quality of life (HRQL), some patients with HF do not demonstrate these benefits, including those patients with a preserved ejection fraction. Provision of palliative care for patients with HF requires an understanding of HF pathogenesis and common medications used for these patients, as well as an approach to balancing life-prolonging and HRQL care strategies. This review describes HF and current targeted therapies and their effects on symptoms, hospital admission rates, exercise performance, HRQL, and survival. Pharmacological interactions with and precautions related to commonly used palliative care medications are reviewed. The goal of this review is to equip palliative care clinicians with information to make evidence-based decisions while managing the balance between optimal disease management and patient quality of life.

Evaluating the risk of hyperkalaemia and acute kidney injury with cotrimoxazole: a retrospective observational study

OBJECTIVES

Increasing antimicrobial resistance has renewed interest in older, less used antimicrobials. Cotrimoxazole shows promise; however, hyperkalaemia and acute kidney injury (AKI) are potential complications. Identifying risk factors for and quantification of these events is required for safe use. This study aimed to evaluate predictors of cotrimoxazole-associated AKI and hyperkalaemia in a clinical setting.

METHODS

Patients prescribed cotrimoxazole were identified using electronic healthcare records over 3 years (1 April 2016 to 31 March 2019). Individual risk factors were recognized. Serum creatinine and potassium trends were analysed over the subsequent 21 days. AKI and patients with hyperkalaemia were classified using Kidney Disease Improving Global Outcomes (KDIGO) and laboratory criteria. Univariate and multiple logistic regression analyses were performed.

RESULTS

Among 214 patients prescribed cotrimoxazole, 42 (19.6%, 95% confidence interval (CI) 14.6-25.7) met AKI criteria and 33 (15.4%, 95% CI 11.0-21.1) developed hyperkalaemia. Low baseline estimated glomerular filtration rate (<60 mL/min/1.73 m², odds ratio (OR) 7.78, 95% CI 3.57-16.13, p < 0.0001) and cardiac disorders (OR 2.40, 95% CI 1.17-4.82, p 0.011) predicted AKI, while low baseline estimated glomerular filtration rate (<60 mL/min/1.73 m², OR 6.80, 95% CI 3.09-15.06, p < 0.0001) and higher baseline serum potassium (p 0.001) predicted hyperkalaemia. Low-dose cotrimoxazole (<1920 mg/d) was associated with lower AKI and hyperkalaemia risk (p 0.007 and 0.019 respectively). Early (within the first 2-4 days of therapy) serum creatinine changes predicted AKI (OR 3.65, 95% CI 1.73-7.41, p 0.001), and early serum potassium changes predicted hyperkalaemia (>0.6 mmol/L, OR 2.47, 95% CI 1.14-5.27, p 0.0236).

CONCLUSIONS

Cotrimoxazole-associated AKI and hyperkalaemia is frequent and dose dependent. Renal function, serum potassium and preexisting cardiac disorders should be evaluated before prescribing cotrimoxazole. Serum creatinine and potassium monitoring within first 2 to 4 days of treatment to identify susceptible patients is recommended, and the lowest effective dose ought to be prescribed.

Evaluation of community pharmacists' knowledge about drug-drug interaction in Central Saudi Arabia

Introduction

Although all implemented and ongoing initiatives, drug-drug interactions (DDIs) are still a global problem. Most published studies about DDIs in Saudi Arabia are carried out in hospital settings. In addition, assessing the knowledge of drug interactions in Saudi Arabia is limited. The aim of our study is to evaluate the knowledge of potential common drug-drug interactions among community pharmacists particularly in Saudi Arabia.

Methodology

A crosses-sectional study utilizing a self- administered questionnaire was conducted among community pharmacy in Riyadh city Saudi Arabia. DDIs' knowledge was assessed by 26 drug pairs. Community pharmacists were asked to select the DDIs as “contraindication”, “may be used together with monitoring”, “no interaction” and “not sure”.

Results

A total of 283 of community pharmacists completed the survey with response rate of 80.9%. Among the 26 drug pairs only 5 of them were identified correctly by most of the participants. To add more 3 out of the 5 pairs had a cutoff of less than 10% between the correct and wrong answer, meaning there still a majority that couldn't identify the correct answer. All the 26 pairs had a statistically significant difference between the correct and incorrect answer.

Conclusion

The results of this study showed that knowledge of community pharmacists about DDIs was inadequate. Community pharmacist should have specific courses in drug interactions to cover the most possible interactions that can be seen in this setting.

Risk of adverse outcomes following urinary tract infection in older people with renal impairment: Retrospective cohort study using linked health record data

BACKGROUND

Few studies have investigated the risk of adverse outcomes in older people with renal impairment presenting to primary care with a urinary tract infection (UTI). The aim of this study was to determine the risk of adverse outcomes in patients aged ≥65 years presenting to primary care with a UTI, by estimated glomerular filtration rate (eGFR) and empirical prescription of nitrofurantoin versus trimethoprim.

METHODS AND FINDINGS

This was a retrospective cohort study using linked health record data from 795,484 patients from 393 general practices in England, who were aged ≥65 years between 2010 and 2016. Patients were entered into the cohort if they presented with a UTI and had a creatinine measurement in the 24 months prior to presentation. We calculated an eGFR to estimate risk of adverse outcomes by renal function, and propensity-score matched patients with eGFRs <60 mL/minute/1.73 m2 to estimate risk of adverse outcomes between those prescribed trimethoprim and nitrofurantoin. Outcomes were 14-day risk of reconsultation for urinary symptoms and same-day antibiotic prescription (proxy for treatment nonresponse), hospitalisation for UTI, sepsis, or acute kidney injury (AKI), and 28-day risk of death. Of 123,607 eligible patients with a UTI, we calculated an eGFR for 116,945 (95%). Median age was 76 (IQR, 70-83) years and 32,428 (28%) were male. Compared to an eGFR of >60 mL/minute/1.73 m2, patients with an eGFR of <60 mL/minute/1.73 m2 had greater odds of hospitalisation for UTI (adjusted odds ratios [ORs] ranged from 1.14 [95% confidence interval (CI) 1.01-1.28, p = 0.028], for eGFRs of 45-59, to 1.68 [95% CI 1.01-2.82, p < 0.001] for eGFRs <15) and AKI (adjusted ORs ranged from 1.57 [95% CI 1.29-1.91, p < 0.001], for eGFRs of 45-59, to 4.53 [95% CI 2.52-8.17, p < 0.001] for eGFRs <15). Compared to an eGFR of >60 mL/minute/1.73 m2, patients with an eGFR <45 had significantly greater odds of hospitalisation for sepsis, and those with an eGFR <30 had significantly greater odds of death. Compared to trimethoprim, nitrofurantoin prescribing was associated with lower odds of hospitalisation for AKI (ORs ranged from 0.62 [95% CI 0.40-0.94, p = 0.025], for eGFRs of 45-59, to 0.45 [95% CI 0.25-0.81, p = 0.008] for eGFRs <30). Nitrofurantoin was not associated with greater odds of any adverse outcome. Our study lacked data on urine microbiology and antibiotic-related adverse events. Despite our design, residual confounding may still have affected some of our findings.

CONCLUSIONS

Older patients with renal impairment presenting to primary care with a UTI had an increased risk of UTI-related hospitalisation and death, suggesting a need for interventions that reduce the risk of these adverse outcomes. Nitrofurantoin prescribing was not associated with an increased risk of adverse outcomes in patients with an eGFR <60 mL/minute/1.73 m2 and could be used more widely in this population.

Evaluation of laboratory disturbance risk when adding low-dose cotrimoxazole for PJP prophylaxis to regimens of high-grade glioma patients taking RAAS inhibitors

BACKGROUND

Cotrimoxazole is associated with the development of hyponatremia, hyperkalemia and elevated serum creatinine, especially when combined with inhibitors of the renin-angiotensin-aldosterone system (RAAS). Pneumocystis jirovecii pneumonia (PJP) prophylaxis is the standard of care for high-grade glioma (HGG) patients receiving temozolomide concurrently with radiotherapy, low-dose cotrimoxazole being the preferred agent. Many of these patients are also taking renin-angiotensin-aldosterone system inhibitors, however the risk of significant laboratory disturbance in these patients remains undescribed.

OBJECTIVE

We evaluated whether high-grade glioma patients taking renin-angiotensin-aldosterone system inhibitors receiving low-dose cotrimoxazole for Pneumocystis jirovecii pneumonia prophylaxis are at additional risk of laboratory disturbances in comparison with their non-renin-angiotensin-aldosterone system counterparts.

METHODS

We conducted a retrospective chart review of adult neuro-oncology patients treated for WHO Grade III or IV glioma between 2013 and 2016. Patient serum Na, K, creatinine, and eGFR were compared (renin-angiotensin-aldosterone system vs. non-renin-angiotensin-aldosterone system) using the chi-square test. Binary logistic regression analysis was then performed to account for differences between cohorts.

RESULTS

Of 63 patients (35 non-renin-angiotensin-aldosterone system, 28 renin-angiotensin-aldosterone system), patients in the renin-angiotensin-aldosterone system cohort were more likely to experience a laboratory disturbance (odds ratio=3.17, p = 0.03). Overall, these disturbances were moderate, but were slightly more common and slightly more severe in the renin-angiotensin-aldosterone system cohort.

CONCLUSION

Adding low-dose cotrimoxazole for Pneumocystis jirovecii pneumonia prophylaxis to the regimens of patients with high-grade glioma taking renin-angiotensin-aldosterone system inhibitors increases the risk of laboratory disturbances. While these are generally moderate, some patients are at risk of significant electrolyte abnormalities requiring intervention.

Pharmacological properties of oral antibiotics for the treatment of uncomplicated urinary tract infections

The therapeutic management of uncomplicated bacterial urinary tract infections (UTIs) is based on short-term courses of oral antibiotics. The preferred drugs are nitrofurantoin trimethoprim-sulfamethoxazole, fosfomycin trometamol, fluoroquinolones and β-lactam agents. The choice of agent for treating uncomplicated UTIs should be based on the pharmacokinetic characteristics of the molecule so that clinical benefit is optimized and the risk of antibacterial resistance is minimized. This article discusses the general pharmacokinetic-pharmacodynamic (PK/PD) aspects of antimicrobial chemotherapy, the PK/PD characteristics of oral antimicrobial agents for the treatment of uncomplicated UTIs and the pharmacological and therapeutic strategies for limiting or preventing bacterial resistance.

Trimethoprim use for urinary tract infection and risk of adverse outcomes in older patients: cohort study

OBJECTIVE

To determine if trimethoprim use for urinary tract infection (UTI) is associated with an increased risk of acute kidney injury, hyperkalaemia, or sudden death in the general population.

DESIGN

Cohort study.

SETTING

UK electronic primary care records from practices contributing to the Clinical Practice Research Datalink linked to the Hospital Episode Statistics database.

PARTICIPANTS

Adults aged 65 and over with a prescription for trimethoprim, amoxicillin, cefalexin, ciprofloxacin, or nitrofurantoin prescribed up to three days after a primary care diagnosis of UTI between April 1997 and September 2015.

MAIN OUTCOME MEASURES

The outcomes were acute kidney injury, hyperkalaemia, and death within 14 days of a UTI treated with antibiotics.

RESULTS

Among a cohort of 1 191 905 patients aged 65 and over, 178 238 individuals were identified with at least one UTI treated with antibiotics, comprising a total of 422 514 episodes of UTIs treated with antibiotics. The odds of acute kidney injury in the 14 days following antibiotic initiation were higher following trimethoprim (adjusted odds ratio 1.72, 95% confidence interval 1.31 to 2.24) and ciprofloxacin (1.48, 1.03 to 2.13) compared with amoxicillin. The odds of hyperkalaemia in the 14 days following antibiotic initiation were only higher following trimethoprim (2.27, 1.49 to 3.45) compared with amoxicillin. However, the odds of death within the 14 days following antibiotic initiation were not higher with trimethoprim than with amoxicillin: in the whole population the adjusted odds ratio was 0.90 (95% confidence interval 0.76 to 1.07) while among users of renin-angiotensin system blockers the odds of death within 14 days of antibiotic initiation was 1.12 (0.80 to 1.57). The results suggest that, for 1000 UTIs treated with antibiotics among people 65 and over, treatment with trimethoprim instead of amoxicillin would result in one to two additional cases of hyperkalaemia and two admissions with acute kidney injury, regardless of renin-angiotensin system blockade. However, for people taking renin-angiotensin system blockers and spironolactone treatment with trimethoprim instead of amoxicillin there were 18 additional cases of hyperkalaemia and 11 admissions with acute kidney injury.

CONCLUSION

Trimethoprim is associated with a greater risk of acute kidney injury and hyperkalaemia compared with other antibiotics used to treat UTIs, but not a greater risk of death. The relative risk increase is similar across population groups, but the higher baseline risk among those taking renin-angiotensin system blockers and potassium-sparing diuretics translates into higher absolute risks of acute kidney injury and hyperkalaemia in these groups.

Explicit definitions of potentially inappropriate prescriptions of antibiotics in older patients: a compilation derived from a systematic review

Potentially inappropriate prescriptions (PIPs) of antibiotics (antibiotic-PIPs) are generally detected by applying implicit definitions based on expert opinion. Explicit definitions are less frequently used, even though this approach would enable the automated detection of antibiotic-PIPs in electronic health records. Here, explicit definitions of antibiotic-PIPs used in studies of older adults were systematically reviewed. The MEDLINE^®, Scopus^® and Web of Science^TM core collection databases were searched with a combination of three terms and their synonyms: 'potentially inappropriate prescription' AND 'antibiotic treatment' AND 'older patients'. Following standardised selection of publications, explicit definitions of antibiotic-PIPs were extracted and were classified into infectious diseases domains and subdomains. A total of 600 search queries identified 4270 records, 93 of which were selected for review. A total of 160 mentions of antibiotic-PIPs were found, corresponding to 62 distinct definitions in 19 infectious diseases domains. Nearly one-half of the definitions were related to upper respiratory tract infections (n = 11 definitions; 17.7%), lower respiratory tract infections (n = 8; 12.9%) and drug-drug interactions (n = 11; 17.7%). Almost 75% of definitions (n = 46) were mentioned in a single study only. Only three definitions concerned critically important antibiotics such as third-generation cephalosporins and fluoroquinolones. This systematic review identified 62 explicit definitions of antibiotic-PIPs. Most of the definitions were not found in more than one study and they varied in the degree of precision. We advocate the implementation of an expert consensus on explicit definitions of antibiotic-PIPs that correspond to today's challenges in public health.

Potassium: friend or foe?

The kidney plays an essential role in maintaining homeostasis of ion concentrations in the blood. Because the concentration gradient of potassium across the cell membrane is a key determinant of the membrane potential of cells, even small deviations in serum potassium level from the normal setpoint can lead to severe muscle dysfunction, resulting in respiratory failure and cardiac arrest. Less severe hypo- and hyperkalemia are also associated with morbidity and mortality across various patient populations. In addition, deficiencies in potassium intake have been associated with hypertension and adverse cardiovascular and renal outcomes, likely due in part to the interrelated handling of sodium and potassium by the kidney. Here, data on the beneficial effects of potassium on blood pressure and cardiovascular and renal outcomes will be reviewed, along with the physiological basis for these effects. In some patient populations, however, potassium excess is deleterious. Risk factors for the development of hyperkalemia will be reviewed, as well as the risks and benefits of existing and emerging therapies for hyperkalemia.

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

AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Drug-drug interactions and adverse drug reactions in polypharmacy among older adults: an integrative review

OBJECTIVE

to identify and summarize studies examining both drug-drug interactions (DDI) and adverse drug reactions (ADR) in older adults polymedicated.

METHODS

an integrative review of studies published from January 2008 to December 2013, according to inclusion and exclusion criteria, in MEDLINE and EMBASE electronic databases were performed.

RESULTS

forty-seven full-text studies including 14,624,492 older adults (≥ 60 years) were analyzed: 24 (51.1%) concerning ADR, 14 (29.8%) DDI, and 9 studies (19.1%) investigating both DDI and ADR. We found a variety of methodological designs. The reviewed studies reinforced that polypharmacy is a multifactorial process, and predictors and inappropriate prescribing are associated with negative health outcomes, as increasing the frequency and types of ADRs and DDIs involving different drug classes, moreover, some studies show the most successful interventions to optimize prescribing.

CONCLUSIONS

DDI and ADR among older adults continue to be a significant issue in the worldwide. The findings from the studies included in this integrative review, added to the previous reviews, can contribute to the improvement of advanced practices in geriatric nursing, to promote the safety of older patients in polypharmacy. However, more research is needed to elucidate gaps.

OBJETIVO

identificar e sintetizar estudos que examinam as interações medicamentosas (IM) e reações adversas a medicamentos (RAM) em idosos polimedicados.

MÉTODOS

revisão integrativa de estudos publicados de janeiro de 2008 a dezembro de 2013, de acordo com critérios de inclusão e exclusão, nas bases de dados eletrônicas MEDLINE e EMBASE.

RESULTADOS

foram analisados 47 estudos de texto completo, incluindo 14,624,492 idosos (≥ 60 anos): 24 (51,1%) sobre RAM, 14 (29,8%) sobre IM e 9 estudos (19,1%) que investigaram tanto IM como RAM. Encontramos uma variedade de desenhos metodológicos. Os estudos revisados reforçaram que a polifarmácia é um processo multifatorial, e os preditores e a prescrição inadequada estão associados a resultados negativos de saúde, como aumento da frequência e tipos de RAM e IM envolvendo diferentes classes de drogas, além disso, alguns estudos mostram as intervenções mais bem-sucedidas para otimizar a prescrição.

CONCLUSÕES

IM e RAM entre idosos continuam a ser um problema significativo no mundo todo. Os resultados dos estudos incluídos nesta revisão integrativa, adicionado às revisões anteriores, podem contribuir para a melhoria das práticas avançadas de enfermagem geriátrica, para promover a segurança dos pacientes idosos em polifarmácia. No entanto, são necessárias mais pesquisas para elucidar lacunas.

OBJETIVO

identificar y resumir los estudios que analizan tanto las interacciones medicamentosas (IM) como las reacciones adversas a medicamentos (RAM) en los adultos mayores polimedicados.

MÉTODOS

revisión integradora de estudios publicados entre enero de 2008 a diciembre de 2013, siguiendo criterios de inclusión y exclusión, en las bases de datos electrónicas MEDLINE y EMBASE.

RESULTADOS

cuarenta y siete estudios de texto completo incluidos fueron analizados incluyendo 14,624,492 adultos mayores (≥ 60 años), de ellos 24 (51,1%) en relación con RAM, 14 (29,9%) con IM y 9 estudios (19,1%) que investigaron tanto IM como RAM. Encontramos una gran variedad de diseños metodológicos. Los estudios revisados reforzaron el concepto que la polifarmacia es un proceso multifactorial, y los predictores y la prescripción inadecuada se asocian con resultados negativos para la salud tales como el aumento de la frecuencia y tipos de RAM y IM implicando diferentes clases de fármacos, además que algunos estudios muestran cuales son las intervenciones más exitosas para optimizar la prescripción.

CONCLUSIONES

IM y RAM siguen siendo un problema importante en el mundo entero entre los adultos mayores. Los resultados de los estudios incluidos en esta revisión integradora, sumado a las revisiones previas, pueden contribuir a la mejora de las prácticas avanzadas de enfermería geriátrica, para promover la seguridad de los pacientes de mayor edad en la polifarmacia. Sin embargo, se necesita más investigación para esclarecer los vacíos de conocimiento.

SFE/SFHTA/AFCE consensus on primary aldosteronism, part 7: Medical treatment of primary aldosteronism

Spironolactone, which is a potent mineralocorticoid receptor antagonist, represents the first line medical treatment of primary aldosteronism (PA). As spironolactone is also an antagonist of the androgen and progesterone receptor, it may present side effects, especially in male patients. In case of intolerance to spironolactone, amiloride may be used to control hypokaliemia and we suggest that eplerenone, which is a more selective but less powerful antagonist of the mineralocorticoid receptor, be used in case of intolerance to spironolactone and insufficient control of hypertension by amiloride. Specific calcic inhibitors and thiazide diuretics may be used as second or third line therapy. Medical treatment of bilateral forms of PA seem to be as efficient as surgical treatment of lateralized PA for the control of hypertension and the prevention of cardiovascular and renal morbidities. This allows to propose medical treatment of PA to patients with lateralized forms of PA who refuse surgery or to patients with PA who do not want to be explored by adrenal venous sampling to determine whether they have a bilateral or lateralized form.

Renal Insufficiency in Concert with Renin-angiotensin-aldosterone Inhibition Is a Major Risk Factor for Hyperkalemia Associated with Low-dose Trimethoprim-sulfamethoxazole in Adults

OBJECTIVE

Low-dose trimethoprim-sulfamethoxazole (TMP-SMX) is commonly used to prevent pneumocystis pneumonia in daily practice. Previous reports have shown a relationship between high- or standard-dose of TMP-SMX and hyperkalemia, however it remains unclear whether this is true for low-dose TMP-SMX. In this study we sought to determine the risk factors for hyperkalemia associated with low-dose TMP-SMX.

METHODS

In this retrospective cohort study, 186 consecutive adult patients who received TMP-SMX as prophylaxis for pneumocystis pneumonia from January 2014 to January 2015 were evaluated. Data on the patients' age, gender, baseline estimated glomerular filtration rate (eGFR), baseline serum potassium, maximum serum potassium, duration reaching the maximal serum potassium level, dosage, and concomitant use of angiotensin-converting enzyme inhibitors (ACEi)/angiotensin receptor blockers (ARB), β-blockers, non-steroidal anti-inflammatory drugs and potassium-sparing diuretics were retrospectively collected. Hyperkalemia was defined as a serum potassium level ≥5 mEq/L. Univariate and multivariate analyses were performed.

RESULTS

The median age of the patients was 66 years and 51.1% were men. Hyperkalemia associated with low-dose TMP-SMX was observed in 32 patients (17.2%). The median duration to reach the maximal serum potassium level was 12 days. The multivariate logistic regression analysis identified renal insufficiency to be a major risk factor for hyperkalemia associated with low-dose TMP-SMX (eGFR <60 mL/min/1.73 m(2), adjusted OR 4.62). Moreover, in the subpopulation of patients with renal insufficiency, ACEi/ARB use was considered to be a major risk factor for hyperkalemia (adjusted OR 3.96).

CONCLUSION

Renal insufficiency in concert with ACEi/ARB use is a major risk factor for hyperkalemia induced by low-dose TMP-SMX.

Trimethoprim-sulfamethoxazole and risk of sudden death among patients taking spironolactone

BACKGROUND

Trimethoprim-sulfamethoxazole increases the risk of hyperkalemia when used with spironolactone. We examined whether this drug combination is associated with an increased risk of sudden death, a consequence of severe hyperkalemia.

METHODS

We conducted a population-based nested case-control study involving Ontario residents aged 66 years or older who received spironolactone between Apr. 1, 1994, and Dec. 31, 2011. Within this group, we identified cases as patients who died of sudden death within 14 days after receiving a prescription for trimethoprim-sulfamethoxazole or one of the other study antibiotics (amoxicillin, ciprofloxacin, norfloxacin or nitrofurantoin). For each case, we identified up to 4 controls matched by age and sex. We determined the odds ratio (OR) for the association between sudden death and exposure to each antibiotic relative to amoxicillin, adjusted for predictors of sudden death using a disease risk index.

RESULTS

Of the 11,968 patients who died of sudden death while receiving spironolactone, we identified 328 whose death occurred within 14 days after antibiotic exposure. Compared with amoxicillin, trimethoprim-sulfamethoxazole was associated with a more than twofold increase in the risk of sudden death (adjusted OR 2.46, 95% confidence interval [CI] 1.55-3.90). Ciprofloxacin (adjusted OR 1.55, 95% CI 1.02-2.38) and nitrofurantoin (adjusted OR 1.70, 95% CI 1.03-2.79) were also associated with an increased risk of sudden death, although the risk with nitrofurantoin was not apparent in a sensitivity analysis.

INTERPRETATION

The antibiotic trimethoprim-sulfamethoxazole was associated with an increased risk of sudden death among older patients taking spironolactone. When clinically appropriate, alternative antibiotics should be considered in these patients.

Extended-release nifedipine and the risk of intestinal obstruction: a population-based study

OBJECTIVES

To examine the risk of bowel obstruction in older adults during treatment with extended-release nifedipine compared with patients treated with amlodipine.

DESIGN

Retrospective cohort study using multiple linked healthcare databases.

SETTING

Ontario, Canada from 1 April 1997 to 31 December 2010.

PARTICIPANTS

We identified patients aged 66 years and older who started treatment with Adalat XL, an extended-release nifedipine product employing a tablet delivery system associated with mechanical bowel obstruction. For comparison, we studied patients receiving amlodipine, a long-acting calcium channel blocker that does not utilise the same delivery system and has not been implicated as a cause of bowel obstruction. Propensity score matching was used to ensure similarity of patients receiving the two drugs.

PRIMARY OUTCOME MEASURE

HR for the association between extended-release nifedipine relative to amlodipine and hospitalisation for bowel obstruction during therapy.

RESULTS

Over the 13-year study period, we identified 103 657 patients treated with extended-release nifedipine and 204 733 patients treated with amlodipine. In these two groups, 591 (0.6%) and 1185 (0.6%) of patients were hospitalised for bowel obstruction, respectively. We found no difference in the risk of bowel obstruction among patients treated with extended-release nifedipine compared with amlodipine (HR 1.09, 95% CI 0.96 to 1.24).

CONCLUSIONS

Bowel obstruction during treatment with extended-release nidefipine is rare, and the risk is not appreciably greater than that during treatment with amlodipine.

Urinary tract infections in older women: a clinical review

IMPORTANCE

Asymptomatic bacteriuria and symptomatic urinary tract infections (UTIs) in older women are commonly encountered in outpatient practice.

OBJECTIVE

To review management of asymptomatic bacteriuria and symptomatic UTI and review prevention of recurrent UTIs in older community-dwelling women.

EVIDENCE REVIEW

A search of Ovid (Medline, PsycINFO, Embase) for English-language human studies conducted among adults aged 65 years and older and published in peer-reviewed journals from 1946 to November 20, 2013.

RESULTS

The clinical spectrum of UTIs ranges from asymptomatic bacteriuria, to symptomatic and recurrent UTIs, to sepsis associated with UTI requiring hospitalization. Recent evidence helps differentiate asymptomatic bacteriuria from symptomatic UTI. Asymptomatic bacteriuria is transient in older women, often resolves without any treatment, and is not associated with morbidity or mortality. The diagnosis of symptomatic UTI is made when a patient has both clinical features and laboratory evidence of a urinary infection. Absent other causes, patients presenting with any 2 of the following meet the clinical diagnostic criteria for symptomatic UTI: fever, worsened urinary urgency or frequency, acute dysuria, suprapubic tenderness, or costovertebral angle pain or tenderness. A positive urine culture (≥105 CFU/mL) with no more than 2 uropathogens and pyuria confirms the diagnosis of UTI. Risk factors for recurrent symptomatic UTI include diabetes, functional disability, recent sexual intercourse, prior history of urogynecologic surgery, urinary retention, and urinary incontinence. Testing for UTI is easily performed in the clinic using dipstick tests. When there is a low pretest probability of UTI, a negative dipstick result for leukocyte esterase and nitrites excludes infection. Antibiotics are selected by identifying the uropathogen, knowing local resistance rates, and considering adverse effect profiles. Chronic suppressive antibiotics for 6 to 12 months and vaginal estrogen therapy effectively reduce symptomatic UTI episodes and should be considered in patients with recurrent UTIs.

CONCLUSIONS AND RELEVANCE

Establishing a diagnosis of symptomatic UTI in older women requires careful clinical evaluation with possible laboratory assessment using urinalysis and urine culture. Asymptomatic bacteriuria should be differentiated from symptomatic UTI. Asymptomatic bacteriuria in older women should not be treated.

Antibiotic-resistant Escherichia coli in women with acute cystitis in Canada

BACKGROUND

Trimethoprim-sulfamethoxazole (TMP-SMX) has been a traditional first-line antibiotic treatment for acute cystitis; however, guidelines do not recommend TMP-SMX in regions where Escherichia coli resistance exceeds 20%. While resistance is increasing, there are no recent Canadian estimates from a primary care setting to guide prescribing decisions.

METHODS

A total of 330 family physicians assessed 752 women with suspected acute cystitis between 2009 and 2011. Physicians documented clinical features and collected urine for cultures for 430 (57.2%) women. The proportion of resistant isolates of E coli and exact binomial 95% CIs were estimated nationally, and compared regionally and demographically. These estimates were compared with those from a 2002 national study.

RESULTS

The proportion of TMP-SMX-resistant E coli was 16.0% nationally (95% CI 11.3% to 21.8%). This was not statistically higher than 2002 (10.9% [P=0.14]). TMP-SMX resistance was increased in women ≤50 years of age (21.4%) compared with older women (10.7% [P=0.037]). In women with no antibiotic exposure in the previous three months, TMP-SMX-resistant E coli remained more prevalent in younger women (21.8%) compared with older women (4.4% [P=0.003]). The proportion of ciprofloxacin-resistant E coli was 5.5% nationally (95% CI 2.7% to 9.9%), and was increased compared with 2002 (1.1% [P=0.036]). Ciprofloxacin resistance was highest in British Columbia (17.7%) compared with other regions (2.7% [P=0.003]), and was increased compared with 2002 levels in this province (0.0% [P=0.025]). Nitrofurantoin-resistant E coli levels were low (0.5% [95% CI 0.01% to 2.7%).

DISCUSSION

The proportion of TMP-SMX-resistant E coli causing acute cystitis in women in Canada remains below 20% nationally, but may exceed this level in premenopausal women. Ciprofloxacin resistance has increased, notably in British Columbia. Nitrofurantoin resistance levels are low across the country. These observations indicate that TMP-SMX and nitrofurantoin remain appropriate empirical antibiotic agents for treating cystitis in primary care settings in Canada.

Studies on the use of BD Vacutainer® SST II™ and RST™ in general practice: investigation of artefactual hyperkalaemia

Background

Current sampling and transport conditions of samples in general practice can result in pseudohyperkalaemia. This study was undertaken to determine, in a general practice setting, whether there is any difference in haemolysis obtained when using BD Vacutainer® Rapid Serum Tubes (BD RST) compared with using BD Vacutainer® SST™ II Advance Blood Collection Tubes (BD SSTII).

Methods

Blood was collected from 353 patients requiring blood sampling who were attending 31 general practitioner practices in Belgium. For each patient, two BD SSTII tubes and two BD RST tubes were drawn in a randomized order. One of each pair of tubes was inverted five times, the other was not. Serum potassium concentration, serum LDH activity and haemolysis index were measured in each sample.

Results

There was no significant difference in measured potassium concentration according to tube type ( P = 0.16). Measured LDH activities were 1.7% higher in serum collected into BD SSTII tubes compared to BD RST tubes ( P = 0.02). When comparing serum from unmixed BD RST with BD SSTII tubes, there was a slight reduction in the haemolysis index but no significant difference in measured potassium concentration or LDH activity. Risk of hyperkalaemia was 4.8 times higher in serum from tubes that were incompletely filled compared to those that were filled with the correct amount of blood.

Conclusion

Both types of blood tubes are suitable for the measurement of serum potassium and LDH in patients from general practice. Tube inversion does not improve the accuracy of either serum potassium or LDH measurement. Blood tubes should be filled to the level recommended by the manufacturer to avoid artefactual increases in measured serum potassium concentration and LDH activity.

Antibiotics-related adverse events in the infectious diseases department of a French teaching hospital: a prospective study

Antibiotics are a significant cause of adverse events (AE), but few studies have focused on prescriptions in hospitalized patients. In infectious diseases departments, the high frequency and diversity of antibiotics prescribed makes AE post-marketing monitoring easier. The aim of our study was to assess the incidence and type of AE in the infectious diseases department of a French teaching tertiary-care hospital. The main characteristics of each hospitalization, including all antibiotics prescribed and any significant AE were recorded prospectively in the medical dashboard of the department. We included all patients having suffered an AE due to systemic antibiotics between January 2008 and March 2011. Among the 3963 hospitalized patients, 2682 (68%) received an antibiotic and 151/2682 (5.6%) suffered an AE. Fifty-two (34%) AE were gastrointestinal disorders, 32 (21%) dermatological, 20 (13%) hepatobiliary, 16 (11%) renal and urinary disorders, 13 (9%) neurological and 11 (7%) blood disorders. Rifampin, fosfomycin, cotrimoxazole and linezolid were the leading causes of AE. Sixty-two percent of the antibiotics causing an AE were stopped and 38% were continued (including 11% with a dose modification). Patients suffering from AE had an increased length of stay (18 vs 10 days, P < 0.001). Our data could help choosing the safest antibiotic when several options are possible.

Spironolactone, eplerenone and the new aldosterone blockers in endocrine and primary hypertension

Mineralocorticoid receptor antagonists (MRAs) are commonly used to reduce blood pressure, left-ventricular hypertrophy, and urinary albumin excretion in patients with essential hypertension or primary aldosteronism. Effects of MRAs on hypertensive organ damage seem to occur beyond what is expected from the mere reduction of blood pressure. This suggests that activation of the mineralocorticoid receptor plays a central role in the development of cardiac and renal abnormalities in hypertensive patients. However, broad use of classic MRAs such as spironolactone has been limited by significant incidence of gynecomastia and other sex-related adverse effects. To overcome these problems, new aldosterone blockers have been developed with different strategies that include use of nonsteroidal MRAs and inhibition of aldosterone synthesis. Both strategies have been designed to avoid the steroid receptor cross-reactivity of classic MRAs that accounts for most adverse effects. Moreover, inhibition of aldosterone synthesis could have an additional benefit due to blockade of the mineralocorticoid receptor-independent pathways that might account for some of the untoward effects of aldosterone. The new aldosterone blockers are currently having extensive preclinical evaluation, and one of these compounds has passed phase 2 trials showing promising results in patients with primary hypertension and primary aldosteronism. This narrative review summarizes the knowledge on the use of classic MRAs in hypertension and covers the evidence currently available on new aldosterone blockers.

Complications of antibiotic therapy

Antibiotics have greatly changed the practice of medicine for the better. Many infections commonly treated in the outpatient setting with antibiotics (eg, urinary tract infections, streptococcal pharyngitis), which previously caused significant morbidity and mortality, are now typically benign. However, with antibiotic therapy come side effects, ranging in severity from mild nausea to life-threatening cytopenias. This article highlights important complications of antibiotic therapy that may be encountered by outpatient providers. Side effects by system are discussed, and a few important drug-specific complications and important drug-drug interactions highlighted.

Polypharmacy in the elderly from the clinical toxicologist perspective

INTRODUCTION

Polypharmacy is closely associated with multimorbidity in the elderly and can lead to problems and drug interactions.

AIM

This study assessed polypharmacy in the elderly, tracking inquiries to the Poison Information Centre Nuremberg (PICN) and patients needing toxicological intensive care therapy.

METHODS

From 2006-2009, all PICN inquiries involving individuals > 70 years were tracked, as were cases at the Toxicological Intensive Care Unit (T-ICU) regarding adverse drug reactions (ADRs) and drug poisoning.

RESULTS

Of 11,683 PICN calls about pharmaceuticals, 175 (1.5%) were from people > 70 years; 156 (4.8%) of 3,272 T-ICU patients were > 70 years. Calls about psychopharmaceuticals (46.9%) and analgesics (25.7%) were most frequent. Among the T-ICU patients, psychopharmaceuticals like sedatives and hypnotics were frequently involved (20.5%), as were tricyclic antidepressants (17.9%) and analgesics (29.5%). Ethanol was co-ingested by 18.3%.

CONCLUSION

Population-specific poison prevention strategies are needed to reduce toxic exposures. Such strategies could include pharmacist intervention, improved prescriber communication and education regarding the geriatric population, and computerized drug databases.

Mineralocorticoid receptor antagonists for heart failure with reduced ejection fraction: integrating evidence into clinical practice

Mineralocorticoid receptor antagonists (MRAs) improve survival and reduce morbidity in patients with heart failure, reduced ejection fraction (HF-REF), and mild-to-severe symptoms, and in patients with left ventricular systolic dysfunction and heart failure after acute myocardial infarction. These clinical benefits are observed in addition to those of angiotensin converting enzyme inhibitors or angiotensin receptor blockers and beta-blockers. The morbidity and mortality benefits of MRAs may be mediated by several proposed actions, including antifibrotic mechanisms that slow heart failure progression, prevent or reverse cardiac remodelling, or reduce arrhythmogenesis. Both eplerenone and spironolactone have demonstrated survival benefits in individual clinical trials. Pharmacologic differences exist between the drugs, which may be relevant for therapeutic decision making in individual patients. Although serious hyperkalaemia events were reported in the major MRA clinical trials, these risks can be mitigated through appropriate patient selection, dose selection, patient education, monitoring, and follow-up. When used appropriately, MRAs significantly improve outcomes across the spectrum of patients with HF-REF.