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

Timing Matters: A Machine Learning Method for the Prioritization of Drug-Drug Interactions Through Signal Detection in the FDA Adverse Event Reporting System and Their Relationship with Time of Co-exposure

INTRODUCTION

Current drug-drug interaction (DDI) detection methods often miss the aspect of temporal plausibility, leading to false-positive disproportionality signals in spontaneous reporting system (SRS) databases.

OBJECTIVE

This study aims to develop a method for detecting and prioritizing temporally plausible disproportionality signals of DDIs in SRS databases by incorporating co-exposure time in disproportionality analysis.

METHODS

The method was tested in the Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS). The CRESCENDDI dataset of positive controls served as the primary source of true-positive DDIs. Disproportionality analysis was performed considering the time of co-exposure. Temporal plausibility was assessed using the flex point of cumulative reporting of disproportionality signals. Potential confounders were identified using a machine learning method (i.e. Lasso regression).

RESULTS

Disproportionality analysis was conducted on 122 triplets with more than three cases, resulting in the prioritization of 61 disproportionality signals (50.0%) involving 13 adverse events, with 61.5% of these included in the European Medicine Agency's (EMA's) Important Medical Event (IME) list. A total of 27 signals (44.3%) had at least ten cases reporting the triplet of interest, and most of them (n = 19; 70.4%) were temporally plausible. The retrieved confounders were mainly other concomitant drugs.

CONCLUSIONS

Our method was able to prioritize disproportionality signals with temporal plausibility. This finding suggests a potential for our method in pinpointing signals that are more likely to be furtherly validated.

Evaluation of effectiveness, hyperkalaemia, and hepatotoxicity of trimethoprim-sulphamethoxazole prophylaxis for Pneumocystis jirovecii pneumonia in paediatric patients: A single-centre retrospective study

BACKGROUND

American guidelines recommend trimethoprim-sulphamethoxazole (TMP-SMX) for preventing Pneumocystis jirovecii pneumonia (PJP) in paediatric patients at doses of 5-10 mg/kg/d of the TMP component, administered either daily, three times weekly, or twice weekly. However, limited studies describe the effectiveness and safety of these prophylactic regimens. Our study aimed to assess the clinical effectiveness and incidence of adverse events associated with each TMP-SMX regimen in paediatric patients, and to identify risk factors for adverse events.

METHODS

We collected data regarding the onset of PJP, hyperkalaemia, and hepatotoxicity in patients aged 0-18 years who underwent prophylaxis with TMP-SMX from July 2018 to June 2023.

RESULTS

A total of 215 paediatric patients met the inclusion criteria. No patients developed PJP. Hyperkalaemia occurred in 14.7%, patients receiving TMP-SMX daily, 15.4% receiving it three times weekly, and 15.5% receiving it twice weekly. Hepatotoxicity was most frequent in patients receiving TMP-SMX twice weekly (19%), followed by those receiving it three times weekly (7.7%), and daily (5.9%). Younger patients were significantly more prone to developing hyperkalaemia or hepatotoxicity. Patients aged <1 year had the highest incidences of hyperkalaemia (56.5%), and those aged 1-2 years had the highest incidence of hepatotoxicity (25%).

CONCLUSIONS

No patient developed PJP under various dosage prophylactic regimens of TMP-SMX. However, our findings suggest the need to monitor potassium levels and hepatic function in patients undergoing any of the three TMP-SMX regimens. In particular, patients aged <1 year old and 1-2 years old face a higher risk of hyperkalaemia and hepatotoxicity, respectively.

Antibiotic-Associated Acute Kidney Injury Among Older Adults: A Case-Crossover Study

BACKGROUND AND OBJECTIVES

Drug-related acute kidney injury is quite common in older adults. The associated drugs, including antibiotics, are often co-prescribed. The objective of this study was to ascertain antibiotic-associated acute kidney injury (AKI) in older adults aged 65 years or above in New Zealand using a case-crossover study design.

METHODS

The International Statistical Classification of Diseases and Related Health Problems, tenth revision, Australian modification code N17.x was used to identify all individuals aged 65 years and above with a diagnosis of incident AKI on admission between 1 January 2005 and 31 December 2020, from the New Zealand National Minimum Data Set. A case-crossover cohort for antibiotic exposures, with a 3 day case period and two 30 day washout periods, summed up to a 66 day study period, was created. Using conditional logistic regression, the changed odds of AKI due to exposure to an antibiotic was calculated as matched odds ratios and their 95% confidence intervals.

RESULTS

A total of 2399 incident cases of AKI were identified between 2005 and 2020 among older adults. The adjusted odds of consuming sulfamethoxazole/trimethoprim antibiotic during the case period was 3.57 times (95% CI 2.86-4.46) higher than the reference period among the incident AKI cases. Fluoroquinolone utilization was also associated with incident AKI (adjusted OR = 2.56; 95% CI 1.90-3.46).

CONCLUSION

The potential of sulfamethoxazole/trimethoprim and fluoroquinolones to be associated with AKI raises the significant need for vigilant prescribing of these antibiotics in older adults.

Implementation of a Taxonomy-Based Framework for the Selection of Appropriate Drugs and Outcomes for Real-World Data Signal Detection Studies

INTRODUCTION

For signal detection studies investigating either drug safety or method evaluation, the choice of drug-outcome pairs needs to be tailored to the planned study design and vice versa. While this is well understood in hypothesis-testing epidemiology, it should be as important in signal detection, but this has not widely been considered. There is a need for a taxonomy framework to provide guidance and a systematic reproducible approach to the selection of appropriate drugs and outcomes for signal detection studies either investigating drug safety or assessing method performance using real-world data.

OBJECTIVE

The aim was to design a general framework for the selection of appropriate drugs and outcomes for signal detection studies given a study design of interest. As a motivating example, we illustrate how the framework is applied to build a reference set for a study aiming to assess the performance of the self-controlled case series with active comparators.

METHODS

We reviewed criteria presented in two published studies which aimed to provide practical advice for choosing the appropriate signal evaluation methodology, and assessed their relevance for signal detection. Further characteristics specific to signal detection were added. The final framework is based on: the application of study design requirements, the database(s) of interest, and the clinical importance of the drug(s) and outcome(s) under consideration. This structure was applied by selecting drug-outcome pairs as a reference set (i.e. list of drug-outcome pairs classified as positive or negative controls) for which the method is expected to work well for a signal detection study aiming to assess the performance of self-controlled case series. Eight criteria were used, related to the application of self-controlled case series assumptions, choice of active comparators, coverage in the database of interest and clinical importance of the outcomes.

RESULTS

After application of the framework, two classes of antibiotics (seven drugs) were selected for the study, and 28 outcomes from all organ classes were chosen from the drug labels, out of the 273 investigated. In total, this corresponds to 104 positive controls (drug-outcome pairs) and 58 negative controls.

CONCLUSIONS

We proposed and applied a framework for the selection of drugs and outcomes for both drug safety signal detection and method assessment used in signal detection to optimise their performance given a study design. This framework will eliminate part of the bias relating to drugs and outcomes not being suited to the method or database. The main difficulty lies in the choice of the criteria and their application to ensure systematic selection, especially as some information remains unknown in signal detection, and clinical judgement was needed on occasions. The same framework could be adapted for other methods.

Treatment of MRSA Infection: Where are We?

Staphylococcus aureus is a leading cause of septicemia, endocarditis, pneumonia, skin and soft tissue infections, bone and joint infections, and hospital-acquired infections. In particular, methicillin-resistant Staphylococcus aureus (MRSA) is associated with high morbidity and mortality, and continues to be a major public health problem. The emergence of multidrug-resistant MRSA strains along with the wide consumption of antibiotics has made anti-MRSA treatment a huge challenge. Novel treatment strategies (e.g., novel antimicrobials and new administrations) against MRSA are urgently needed. In the past decade, pharmaceutical companies have invested more in the research and development (R&D) of new antimicrobials and strategies, spurred by favorable policies. All research articles were collected from authentic online databases, including Google Scholar, PubMed, Scopus, and Web of Science, by using different combinations of keywords, including 'anti-MRSA', 'antibiotic', 'antimicrobial', 'clinical trial', 'clinical phase', clinical studies', and 'pipeline'. The information extracted from articles was compared to information provided on the drug manufacturer's website and Clinical Trials.gov (https://clinicaltrials.gov/) to confirm the latest development phase of anti-MRSA agents. The present review focuses on the current development status of new anti-MRSA strategies concerning chemistry, pharmacological target(s), indications, route of administration, efficacy and safety, pharmacokinetics, and pharmacodynamics, and aims to discuss the challenges and opportunities in developing drugs for anti-MRSA infections.

tICA-Metadynamics for Identifying Slow Dynamics in Membrane Permeation

Molecular simulations are commonly used to understand the mechanism of membrane permeation of small molecules, particularly for biomedical and pharmaceutical applications. However, despite significant advances in computing power and algorithms, calculating an accurate permeation free energy profile remains elusive for many drug molecules because it can require identifying the rate-limiting degrees of freedom (i.e., appropriate reaction coordinates). To resolve this issue, researchers have developed machine learning approaches to identify slow system dynamics. In this work, we apply time-lagged independent component analysis (tICA), an unsupervised dimensionality reduction algorithm, to molecular dynamics simulations with well-tempered metadynamics to find the slowest collective degrees of freedom of the permeation process of trimethoprim through a multicomponent membrane. We show that tICA-metadynamics yields translational and orientational collective variables (CVs) that increase convergence efficiency ∼1.5 times. However, crossing the periodic boundary is shown to introduce artifacts in the translational CV that can be corrected by taking absolute values of molecular features. Additionally, we find that the convergence of the tICA CVs is reached with approximately five membrane crossings and that data reweighting is required to avoid deviations in the translational CV.

Affinity-Switchable Interaction of Biotin and Streptavidin for the Signal-ON Detection of Small Molecules

Lateral flow assay (LFA) based on gold nanoparticles (AuNPs) is a widely used analytical device for the rapid analysis of environmental hazards and biomarkers. Typically, a sandwich-type format is used for macromolecule detection, in which the appearance of a red test line indicates a positive result (Signal-ON). In contrast, small molecule detection usually relies on a competitive assay, where the absence of a test line indicates positive testing (Signal-OFF). However, such a "Signal-OFF" reading is usually detected within a narrower dynamic range and tends to generate false-negative signals at a low concentration. Moreover, inconsistent readings between macromolecule and small molecule testing might lead to misinterpretation when used by nonskilled individuals. Herein, we report a "Signal-ON" small molecule competitive assay based on the sterically modulated affinity-switchable interaction of biotin and streptavidin. In the absence of a small molecule target, a large steric hindrance can be imposed on the biotin to prevent interaction with streptavidin. However, in the presence of the small molecule target, this steric effect is removed, allowing the biotin to bind to streptavidin and generate the desired test line. In this article, we demonstrate the selective detection of two small molecule drugs, sulfonamides and trimethoprim, using this simple and modular affinity-switchable lateral flow assay (ASLFA). We believe that this affinity-switchable approach can also be adapted in drug discovery and clinical diagnosis, where the competitive assay format is always used for the rapid analysis of small molecules.

Trimethoprim resistance in surface and wastewater is mediated by contrasting variants of the dfrB gene

Trimethoprim (TMP) is a low-cost, widely prescribed antibiotic. Its effectiveness is increasingly challenged by the spread of genes coding for TMP-resistant dihydrofolate reductases: dfrA, and the lesser-known, evolutionarily unrelated dfrB. Despite recent reports of novel variants conferring high level TMP resistance (dfrB10 to dfrB21), the prevalence of dfrB is still unknown due to underreporting, heterogeneity of the analyzed genetic material in terms of isolation sources, and limited bioinformatic processing. In this study, we explored a coherent set of shotgun metagenomic sequences to quantitatively estimate the abundance of dfrB gene variants in aquatic environments. Specifically, we scanned sequences originating from influents and effluents of municipal sewage treatment plants as well as river-borne microbiomes. Our analyses reveal an increased prevalence of dfrB1, dfrB2, dfrB3, dfrB4, dfrB5, and dfrB7 in wastewater microbiomes as compared to freshwater. These gene variants were frequently found in genomic neighborship with other resistance genes, transposable elements, and integrons, indicating their mobility. By contrast, the relative abundances of the more recently discovered variants dfrB9, dfrB10, and dfrB13 were significantly higher in freshwater than in wastewater microbiomes. Moreover, their direct neighborship with other resistance genes or markers of mobile genetic elements was significantly less likely. Our findings suggest that natural freshwater communities form a major reservoir of the recently discovered dfrB gene variants. Their proliferation and mobilization in response to the exposure of freshwater communities to selective TMP concentrations may promote the prevalence of high-level TMP resistance and thus limit the future effectiveness of antimicrobial therapies.

tICA-Metadynamics for Identifying Slow Dynamics in Membrane Permeation

Molecular simulations are commonly used to understand the mechanism of membrane permeation of small molecules, particularly for biomedical and pharmaceutical applications. However, despite significant advances in computing power and algorithms, calculating an accurate permeation free energy profile remains elusive for many drug molecules because it can require identifying the rate-limiting degrees of freedom (i.e., appropriate reaction coordinates). To resolve this issue, researchers have developed machine learning approaches to identify slow system dynamics. In this work, we apply time-lagged independent component analysis (tICA), an unsupervised dimensionality reduction algorithm, to molecular dynamics simulations with well-tempered metadynamics to find the slowest collective degrees of freedom of the permeation process of trimethoprim through a multicomponent membrane. We show that tICA-metadynamics yields translational and orientational collective variables (CVs) that increase convergence efficiency ∼1.5 times. However, crossing the periodic boundary is shown to introduce artefacts in the translational CV that can be corrected by taking absolute values of molecular features. Additionally, we find that the convergence of the tICA CVs is reached with approximately five membrane crossings, and that data reweighting is required to avoid deviations in the translational CV.

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.

Hyperkalemia by eplerenone or esaxerenone in the presence or absence of clarithromycin in hypertensive patients: a retrospective observational cohort study

OBJECTIVE

Mineralocorticoid receptor antagonists (MRAs), eplerenone and esaxerenone, cause hyperkalemia dose-dependently. We investigated the cytochrome P450 3A4-mediated drug-drug interaction between the MRAs and clarithromycin.

METHODS

This retrospective observational study included adult hypertensive patients with MRA plus clarithromycin or MRA alone with a propensity score matching (1:1). The difference in serum potassium level (ΔK, maximum level - baseline level) between groups was compared using the Mann-Whitney U -test. Linear regression analysis was used to detect variables that correlated with ΔK in patients with MRA plus clarithromycin.

RESULTS

After propensity score matching (each nine patients), serum potassium level was elevated after treatment with MRA plus clarithromycin [4.3 (3.5 to 5.1) meq/l to 4.9 (4.0 to 5.5) meq/l, P  = 0.0234] and MRA alone [4.3 (4.0 to 4.7) meq/l to 4.6 (4.4 to 5.2) meq/l, P  = 0.0469]. Although there was no significant difference in ΔK between groups [MRA plus clarithromycin: 0.5 (0.1 to 1.1) meq/l vs. MRA alone: 0.3 (0.1 to 1.2) meq/l, P  = 0.7231], ΔK was significantly higher in esaxerenone plus clarithromycin than in esaxerenone alone [0.6 (0.5 to 1.1) meq/l vs. 0.1 (0.1 to 0.2) meq/l, P  = 0.0495]. Conversely, clarithromycin did not show a significant effect on ΔK in patients with eplerenone [0.4 (-0.2 to 1.2) meq/l vs. 0.8 (0.1 to 1.3) meq/l, P  = 0.5745]. A positive correlation was found between ΔK and age in patients with MRA plus clarithromycin ( y  = 0.03 ×  x - 1.38, r  = 0.71, P  = 0.0336).

CONCLUSION

The drug-drug interaction between MRAs and clarithromycin was evident, particularly in esaxerenone. Serum potassium levels should be closely monitored in older patients.

Immunogenic multi-epitope-based vaccine development to combat cyclosporiasis of immunocompromised patients applying computational biology method

Cyclospora cayetanensis infections, also known as cyclosporiasis, persist to be the prevalent emerging protozoan parasite and an opportunist that causes digestive illness in immunocompromised individuals. In contrast, this causal agent can affect people of all ages, with children and foreigners being the most susceptible populations. For most immunocompetent patients, the disease is self-limiting; in extreme circumstances, this illness can manifest as severe or persistent diarrhea as well as colonize on secondary digestive organs leading to death. According to recent reports, worldwide 3.55% of people are infected by this pathogen, with Asia and Africa being more prevalent. For the treatment, trimethoprim-sulfamethoxazole is the only licensed drug and does not appear to work as well in some patient populations. Therefore, the much more effective strategy to avoid this illness is immunization through the vaccine. This present study uses immunoinformatics for identifying a computational multi-epitope-based peptide vaccine candidate for Cyclospora cayetanensis. Following the review of the literature, a highly efficient, secure, and vaccine complex based on multi-epitopes was designed by utilizing the identified proteins. These selected proteins were then used to predict non-toxic and antigenic HTL-epitopes, B-cell-epitopes, and CTL-epitopes. Ultimately, both a few linkers and an adjuvant were combined to create a vaccine candidate with superior immunological epitopes. Then, to establish the vaccine-TLR complex binding constancy, the TLR receptor and vaccine candidates were placed into the FireDock, PatchDock, and ClusPro servers for molecular docking and iMODS server for molecular-dynamic simulation. Finally, this selected vaccine construct was cloned into Escherichia coli strain-K12; thus, the constructed vaccines against Cyclospora cayetanensiscould improve the host immune response and can be produced experimentally.

Antibacterial-associated acute kidney injury among older adults: A post-marketing surveillance study using the FDA adverse events reporting system

PURPOSE

Antibacterials induce a differential risk of acute kidney injury (AKI) in older adults. This study investigated the reporting risk of AKI associated with antibacterials using the individual case safety reports (ICSRs) submitted to the Food and Drug Administration Adverse Event Reporting System (FAERS) database.

METHODS

A case/non-case method was used to assess AKI risk associated with antibacterials between 1 January 2000 and 30 September 2021. Cases were ICSRs for antibacterials with AKI as preferred terms included in the Medical Dictionary of Regulatory Activities (MedDRA) system organ classes 'Renal and urinary disorders' disorders. The analyses were completed on a de-duplicated data set containing only the recent version of the ICSR. Signals were defined by a lower 95% confidence interval (CI) of reporting odds ratio (ROR) ≥ 2, proportional reporting ratio (PRR) ≥ 2, information component (IC) > 0, Empirical Bayes Geometric Mean (EBGM) > 1 and reports ≥4. Sensitivity analyses were conducted a priori to assess the robustness of signals.

RESULTS

A total of 3 680 621 reports on ADEs were retrieved from FAERS over the study period, of which 92 194 were antibacterial reports. Gentamicin, sulfamethoxazole, trimethoprim and vancomycin consistently gave strong signals of disproportionality on all four disproportionality measures and across the different sensitivity analyses: gentamicin (ROR = 2.95[2.51-3.46]), sulfamethoxazole (ROR = 2.97[2.68-3.29]), trimethoprim (ROR = 2.81[2.29-3.46]) and vancomycin (ROR = 3.35[3.08-3.64]).

CONCLUSION

Signals for gentamicin, sulfamethoxazole, trimethoprim and vancomycin were confirmed by using antibacterials as a comparator, adjusting for drug-related competition bias and event-related competition bias.

Intestinal Microbiota Correction in the Treatment and Prevention of Urinary Tract Infection

Intestinal microbiota is a topical subject of modern research. The maintenance of a healthy intestinal micro biota is an important component of homeostasis, and violations of its composition and functions, called dysbiosis, are associated with a number of diseases, including urinary tract infections. Antimicrobial therapy leads to significant changes in the intestinal microbiota and causes the possibility of urinary tract infection recurrence. In this regard, it is important to study methods of microbiota correction in order to restore its structural and functional integrity.

Renal Impairment Associated With Trimethoprim-Sulfamethoxazole Use in the Pediatric Population

OBJECTIVE

Limited studies describe acute kidney injury (AKI) in children receiving trimethoprimsulfamethoxazole (SXT). The primary objective of this study was to describe AKI with SXT use in pediatric patients. Secondary objectives included describing the incidence of hyperkalemia and blood dyscrasias with SXT use.

METHODS

In this retrospective, single-center observational study, inpatient electronic medical records were reviewed for patients younger than 18 years of age who received at least 5 days of SXT for treatment of a bacterial infection. Patients were excluded if serum creatinine data prior to and after initiation of SXT were unavailable, they had AKI or were on hemodialysis prior to SXT initiation, or they were admitted to an oncology unit.

RESULTS

Of 98 patients who met inclusion criteria, 24 (24.5%) experienced stage I AKI and 16 (16.3%) experienced stage II or III AKI. The mean treatment duration with SXT at time of AKI development was 5.9 days. Coadministration of SXT with other nephrotoxic medications increased the risk of development of AKI (OR, 1.7; 95% CI, 1.2-2.4). Hyperkalemia was noted in 29 patients (29.6%), anemia in 39 patients (39.8%), thrombocytopenia in 30 (30.6%), and neutropenia in 39 (39.8%).

CONCLUSIONS

Changes in renal function suggestive of AKI occur frequently in pediatric patients receiving at least 5 days of treatment with SXT, particularly when using serum creatinine as a marker of AKI. In contrast, when using urine output rather than serum creatinine, the incidence is much lower and may be more reflective of a true change in renal function. Coadministration of nephrotoxic agents increases the risk of development of AKI. Anemia and hyperkalemia are common in patients receiving SXT and not associated with development of AKI. Further prospective study is warranted to validate these results.

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.

Characteristics of risk factors for acute kidney injury among inpatients administered sulfamethoxazole/trimethoprim: a retrospective observational study

Background

Sulfamethoxazole/trimethoprim (SMX/TMP) potentially increases the serum creatinine levels, resulting in acute kidney injury (AKI). However, the clinical characteristics of the AKI associated with SMX/TMP and the risk factors for its development have not been fully characterized.

Methods

A retrospective cohort observational analysis was conducted on adult inpatients who started SMX/TMP treatment at the Tokyo Women’s Medical University, Yachiyo Medical Center, from April 2018 to March 2020. The primary outcome was AKI, defined as an increase in serum creatinine level of ≥ 50% from baseline. Multivariate logistic regression analysis was used to determine the risk factors for the AKI associated with SMX/TMP.

Results

Of the 281 patients, 32 (11.4%) developed AKI. The multivariate logistic regression analysis identified that body mass index (BMI) (odds ratio [OR] = 0.86, 95% confidence interval [95% CI] 0.76–0.97, p < 0.01), presence of hypertension (OR = 2.69, 95% CI 1.11–6.49, p = 0.02), SMX/TMP daily dose (OR = 1.16, 95% CI 1.03–1.30, p = 0.02), and concomitant loop diuretic use (OR = 2.91, 95% CI 1.08–7.78, p = 0.04) were the associated risk factors for AKI in patients who were administered SMX/TMP.

Conclusions

This study showed that low BMI, hypertension, high-dose SMX/TMP, and concomitant loop diuretic use increased the risk of AKI in patients administered SMX/TMP. Clinicians should consider monitoring the renal function in patients at a high risk of AKI.

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.

Hypothesis-Driven, Structure-Based Design in Photopharmacology: The Case of eDHFR Inhibitors

Photopharmacology uses light to regulate the biological activity of drugs. This precise control is obtained through the incorporation of molecular photoswitches into bioactive molecules. A major challenge for photopharmacology is the rational design of photoswitchable drugs that show light-induced activation. Computer-aided drug design is an attractive approach toward more effective, targeted design. Herein, we critically evaluated different structure-based approaches for photopharmacology with Escherichia coli dihydrofolate reductase (eDHFR) as a case study. Through the iterative examination of our hypotheses, we progressively tuned the design of azobenzene-based, photoswitchable eDHFR inhibitors in five design–make–switch–test–analyze cycles. Targeting a hydrophobic subpocket of the enzyme and a specific salt bridge only with the thermally metastable cis-isomer emerged as the most promising design strategy. We identified three inhibitors that could be activated upon irradiation and reached potencies in the low-nanomolar range. Above all, this systematic study provided valuable insights for future endeavors toward rational photopharmacology.

Defining Baseline Creatinine for Identification of AKI in Population-Based Laboratory Databases: A Danish Nationwide Cohort Study

Background

The baseline creatinine level is central in the Kidney Disease Improving Global Outcomes (KDIGO) criteria of AKI, but baseline creatinine is often inconsistently defined or unavailable in AKI research. We examined the rate, characteristics, and 30-day mortality of AKI in five AKI cohorts created using different definitions of baseline creatinine.

Methods

This nationwide cohort study included all individuals aged ≥18 years in Denmark with a creatinine measurement in 2017. Applying the KDIGO criteria, we created four AKI cohorts using four different baseline definitions (most recent, mean, or median value of outpatient creatinine 365-368 days before, or median value 90-98 days before, if available, otherwise median value 365-391 days before) and one AKI cohort not using a baseline value. AKI rate and the distribution of age, sex, baseline creatinine, and comorbidity were described for each AKI cohort, and the 30-day all-cause mortality was estimated using the Kaplan-Meier method.

Results

The study included 2,095,850 adults with at least one creatinine measurement in 2017. The four different baseline definitions identified between 61,189 and 62,597 AKI episodes. The AKI rate in these four cohorts was 13-14 per 1000 person-years, and 30-day all-cause mortality was 17%-18%. The cohort created without using a baseline creatinine included 37,659 AKI episodes, corresponding to an AKI rate of 8.2 per 1000 person-years and a 30-day mortality of 23%. All five cohorts were similar regarding age, sex, and comorbidity.

Conclusions

In a population-based setting with available outpatient baseline creatinine, different baseline creatinine definitions revealed comparable AKI cohorts, whereas the lack of a baseline creatinine when defining AKI led to a smaller AKI cohort with a higher mortality. These findings underscore the importance of availability and consistent use of an outpatient baseline creatinine, particulary in studies of community-acquired AKI.

Risk of antimicrobial-associated organ injury among the older adults: a systematic review and meta-analysis

Background

Older adults (aged 65 years and above) constitute the fastest growing population cohort in the western world. There is increasing evidence that the burden of infections disproportionately affects older adults, and hence this vulnerable population is frequently exposed to antimicrobials. There is currently no systematic review summarising the evidence for organ injury risk among older adults following antimicrobial exposure. This systematic review and meta-analysis examined the relationship between antimicrobial exposure and organ injury in older adults.

Methodology

We searched for original research articles in PubMed, Embase.com, Web of Science core collection, Web of Science BIOSIS citation index, Scopus, Cochrane Central Register of Controlled Trials, ProQuest, and PsycINFO databases, using key words in titles and abstracts, and using MeSH terms. We searched for all available articles up to 31 May 2021. After removing duplicates, articles were screened for inclusion into or exclusion from the study by two reviewers. The Newcastle-Ottawa scale was used to assess the risk of bias for cohort and case-control studies. We explored the heterogeneity of the included studies using the Q test and I² test and the publication bias using the funnel plot and Egger’s test. The meta-analyses were performed using the OpenMetaAnalyst software.

Results

The overall absolute risks of acute kidney injury among older adults prescribed aminoglycosides, glycopeptides, and macrolides were 15.1% (95% CI: 12.8–17.3), 19.1% (95% CI: 15.4–22.7), and 0.3% (95% CI: 0.3–0.3), respectively. Only 3 studies reported antimicrobial associated drug-induced liver injury. Studies reporting on the association of organ injury and antimicrobial exposure by age or duration of treatment were too few to meta-analyse. The funnel plot and Egger’s tests did not indicate evidence of publication bias.

Conclusion

Older adults have a significantly higher risk of sustaining acute kidney injury when compared to the general adult population. Older adults prescribed aminoglycosides have a similar risk of acute kidney injury to the general adult population.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-021-02512-3.

FTIR, Weight, and Surface Morphology of Poly(vinyl chloride) Doped with Tin Complexes Containing Aromatic and Heterocyclic Moieties

Poly(vinyl chloride) (PVC) is an important synthetic plastic that is produced in large quantities (millions of tons) annually. Additives to PVC are necessary to allow its use in many applications, particularly in harsh conditions. In regard to this, investigation of the synthesis of trimethoprim–tin complexes and their use as PVC additives is reported. Trimethoprim–tin complexes were obtained from the reaction of trimethoprim and tin chlorides using simple procedures. Trimethoprim–tin complexes (0.5% by weight) were added to PVC to produce homogenous mixtures and thin films were made. The effect of ultraviolet irradiation on the surface and properties of the PVC films was investigated. The level of both photodecomposition and photo-oxidation of PVC films containing trimethoprim–tin complexes was observed to be lower than for the blank film. The effectiveness of tin complexes as PVC photostabilizers reflects the aromaticity of the additives. The complex containing three phenyl groups attached to the tin cation showed the most stabilizing effect on PVC. The complex containing two phenyl groups was next, with the one containing butyl substituents resulting in the least stabilization of PVC. A number of mechanisms have been proposed to explain the role of the synthesized complexes in PVC photostabilization.

Antimicrobial Treatment and Prophylaxis of Plague: Recommendations for Naturally Acquired Infections and Bioterrorism Response

This report provides CDC recommendations to U.S. health care providers regarding treatment, pre-exposure prophylaxis, and postexposure prophylaxis of plague. Yersinia pestis, the bacterium that causes plague, leads to naturally occurring disease in the United States and other regions worldwide and is recognized as a potential bioterrorism weapon. A bioweapon attack with Y. pestis could potentially infect thousands, requiring rapid and informed decision making by clinicians and public health agencies. The U.S. government stockpiles a variety of medical countermeasures to mitigate the effects of a bioterrorism attack (e.g., antimicrobials, antitoxins, and vaccines) for which the 21st Century Cures Act mandates the development of evidence-based guidelines on appropriate use. Guidelines for treatment and postexposure prophylaxis of plague were published in 2000 by a nongovernmental work group; since then, new human clinical data, animal study data, and U.S. Food and Drug Administration approvals of additional countermeasures have become available. To develop a comprehensive set of updated guidelines, CDC conducted a series of systematic literature reviews on human treatment of plague and other relevant topics to collect a broad evidence base for the recommendations in this report. Evidence from CDC reviews and additional sources were presented to subject matter experts during a series of forums. CDC considered individual expert input while developing these guidelines, which provide recommended best practices for treatment and prophylaxis of human plague for both naturally occurring disease and following a bioterrorism attack. The guidelines do not include information on diagnostic testing, triage decisions, or logistics involved in dispensing medical countermeasures. Clinicians and public health officials can use these guidelines to prepare their organizations, hospitals, and communities to respond to a plague mass-casualty event and as a guide for treating patients affected by plague.

Compared with Cotrimoxazole Nitroxoline Seems to Be a Better Option for the Treatment and Prophylaxis of Urinary Tract Infections Caused by Multidrug-Resistant Uropathogens: An In Vitro Study

The resistance of uropathogens to various antibiotics is increasing, but nitroxoline remains active in vitro against some relevant multidrug resistant uropathogenic bacteria. E. coli strains, which are among the most common uropathogens, are unanimously susceptible. Thus, nitroxoline is an option for the therapy of urinary tract infections caused by multiresistant bacteria. Since nitroxoline is active against bacteria in biofilms, it will also be effective in patients with indwelling catheters or foreign bodies in the urinary tract. Cotrimoxazole, on the other hand, which, in principle, can also act on bacteria in biofilms, is frequently inactive against multiresistant uropathogens. Based on phenotypic resistance data from a large number of urine isolates, structural characterisation of an MDR plasmid of a recent ST131 uropathogenic E. coli isolate, and publicly available genomic data of resistant enterobacteria, we show that nitroxoline could be used instead of cotrimoxazole for intervention against MDR uropathogens. Particularly in uropathogenic E. coli, but also in other enterobacterial uropathogens, the frequent parallel resistance to different antibiotics due to the accumulation of multiple antibiotic resistance determinants on mobile genetic elements argues for greater consideration of nitroxoline in the treatment of uncomplicated urinary tract infections.

Antimicrobial pharmacokinetics and preclinical in vitro models to support optimized treatment approaches for uncomplicated lower urinary tract infections

INTRODUCTION

Urinary tract infections (UTIs) are extremely common. Millions of people, particularly healthy women, are affected worldwide every year. One-in-two women will have a recurrence within 12-months of an initial UTI. Inadequate treatment risks worsening infection leading to acute pyelonephritis, bacteremia and sepsis. In an era of increasing antimicrobial resistance, it is critical to provide optimized antimicrobial treatment.

AREAS COVERED

Literature was searched using PubMed and Google Scholar (up to 06/2020), examining the etiology, diagnosis and oral antimicrobial therapy for uncomplicated UTIs, with emphasis on urinary antimicrobial pharmacokinetics (PK) and the application of dynamic in vitro models for the pharmacodynamic (PD) profiling of pathogen response.

EXPERT OPINION

The majority of antimicrobial agents included in international guidelines were developed decades ago without well-described dose-response relationships. Microbiology laboratories still apply standard diagnostic methodology that has essentially remained unchanged for decades. Furthermore, it is uncertain how relevant standard in vitro susceptibility is for predicting antimicrobial efficacy in urine. In order to optimize UTI treatments, clinicians must exploit the urine-specific PK of antimicrobial agents. Dynamic in vitro models are valuable tools to examine the PK/PD and urodynamic variables associated with UTIs, while informing uropathogen susceptibility reporting, optimized dosing schedules, clinical trials and treatment guidelines.

Hyperkalemia: pathophysiology, risk factors and consequences

There have been significant recent advances in our understanding of the mechanisms that maintain potassium homoeostasis and the clinical consequences of hyperkalemia. In this article we discuss these advances within a concise review of the pathophysiology, risk factors and consequences of hyperkalemia. We highlight aspects that are of particular relevance for clinical practice. Hyperkalemia occurs when renal potassium excretion is limited by reductions in glomerular filtration rate, tubular flow, distal sodium delivery or the expression of aldosterone-sensitive ion transporters in the distal nephron. Accordingly, the major risk factors for hyperkalemia are renal failure, diabetes mellitus, adrenal disease and the use of angiotensin-converting enzyme inhibitors, angiotensin receptor blockers or potassium-sparing diuretics. Hyperkalemia is associated with an increased risk of death, and this is only in part explicable by hyperkalemia-induced cardiac arrhythmia. In addition to its well-established effects on cardiac excitability, hyperkalemia could also contribute to peripheral neuropathy and cause renal tubular acidosis. Hyperkalemia-or the fear of hyperkalemia-contributes to the underprescription of potentially beneficial medications, particularly in heart failure. The newer potassium binders could play a role in attempts to minimize reduced prescribing of renin-angiotensin inhibitors and mineraolocorticoid antagonists in this context.

Risk of acute kidney injury following community prescription of antibiotics: self-controlled case series

BACKGROUND

Development of acute kidney injury (AKI) following the use of antibiotics such as sulphonamides, trimethoprim and aminoglycosides is a frequently described phenomenon. More recently, an association between fluoroquinolone use and AKI has been suggested. The aim of this study was to evaluate the risk of AKI as an unintended consequence of commonly prescribed antibiotics in a large community cohort using a method that fully adjusts for underlying patient characteristics, including potential unmeasured confounders.

METHODS

A self-controlled case study was conducted and included all individuals aged 18 years and over in the Tayside region of Scotland who had a serum creatinine measured between 1 January 2004 and 31 December 2012. AKI episodes were defined using the Kidney Disease: Improving Global Outcomes definition. Data on oral community-prescribed antibiotics (penicillins, cephalosporins, fluoroquinolones, sulphonamides and trimethoprim, macrolides and nitrofurantoin) were collected for all individuals. Incidence rate ratios (IRRs) for AKI associated with antibiotic exposure versus time periods without antibiotic exposure were calculated.

RESULTS

Combined use of sulphonamides, trimethoprim and nitrofurantoin rose by 47% and incidence of community-acquired AKI rose by 16% between 2008 and 2012. During the study period 12 777 individuals developed 14 900 episodes of AKI in the community, of which 68% was AKI Stage 1, 16% Stage 2 and 16% Stage 3. The IRR of AKI during any antibiotic use was 1.16 [95% confidence interval (CI) 1.10-1.23], and this was highest during sulphonamides or trimethoprim use; IRR 3.07 (95% CI 2.81-3.35). Fluoroquinolone and nitrofurantoin use was not associated with a significantly increased rate of AKI; IRR 1.13 (95% CI 0.94-1.35) and 1.16 (95% CI 0.91-1.50), respectively.

CONCLUSIONS

Incidence of AKI rose by 16% between 2008 and 2012. In the same period the use of sulphonamides, trimethoprim and nitrofurantoin increased by 47%. A significant increased risk of AKI was seen with the use of sulphonamides and trimethoprim, but not with fluoroquinolones or nitrofurantoin.

Management of Urinary Tract Infections in Direct to Consumer Telemedicine

BACKGROUND

Urinary tract infections (UTI) are a common reason for seeking care via direct to consumer (DTC) telemedicine, yet patterns of care, including antibiotic prescribing, have not been reported.

OBJECTIVE

To describe management of UTI in a large nationwide DTC telemedicine platform.

DESIGN

Cross-sectional observational study.

PARTICIPANTS

Patients seeking care for or diagnosed with UTI via DTC telemedicine between July 2016 and July 2018.

MAIN MEASURES

Patient measures included age, sex, geographic region, satisfaction with care, and patient-reported call reason. High-risk patients were defined as males, patients over 65 years, or those diagnosed with pyelonephritis. Physician measures included specialty and geographic region. Antibiotic prescription was assessed overall and by antibiotic type. Variation in antibiotic prescriptions was assessed by patient and physician factors, including geographic region of both parties.

KEY RESULTS

Of the 20,600 patients diagnosed with a UTI during the study period, 96% were female. Most (84%) stated their call reason was a UTI. Overall, 94% of UTI patients received an antibiotic; 56% got nitrofurantoin, 29% got trimethoprim-sulfamethoxazole, and 10% got a quinolone. Receipt of an antibiotic was associated with higher satisfaction with care (p < 0.001). While nitrofurantoin was the most common antibiotic for all physician regions, antibiotic type varied by physician region. Of the 6% of the study population defined as high risk, 69% received an antibiotic: 72% of males, 91% of women over 65, and 21% of patients diagnosed with pyelonephritis.

CONCLUSIONS

Management of UTI via DTC telemedicine appears to be appropriate for average-risk patients, and most are able to self-diagnose. Most patients received guideline-concordant care, but over half of high-risk patients received antibiotics. DTC telemedicine offers convenient, low-cost care that is generally appropriate. Efforts should be made to ensure high-risk patients get proper follow-up.

Empirical treatment of urinary tract infections: how rational are our guidelines?

Objectives

This study considers susceptibility test results obtained over a 6 month period for Enterobacteriaceae that caused urinary tract infections (UTIs) in the Cork region of Ireland and uses these results to examine the suitability of Irish empirical treatment guidelines.

Patients and methods

UTI-causing Enterobacteriaceae isolates were analysed using EUCAST guidelines to determine resistance to a set of commonly prescribed antimicrobial agents, i.e. ampicillin, amoxicillin/clavulanate, cefalexin, ciprofloxacin, nitrofurantoin and trimethoprim. Patients were categorized by age and patient type, based on origin (hospital inpatients, patients in long-term care facilities and all other non-hospitalized patients). In total, 8999 test results were analysed using the IBM Cognos Analytics Series 7 interrogation tool and Microsoft Office Excel.

Results

A variety of resistance patterns were observed. Only one antimicrobial agent, nitrofurantoin, demonstrated a resistance rate of less than 20% for all patient categories considered.

Conclusions

Previous studies determined that a resistance rate of >20% renders an antimicrobial agent unsuitable for use as an empirical treatment option. This study demonstrated that this resistance rate is exceeded in many cases, potentially rendering some antimicrobial agents unsuitable for use as empirical treatment. We suggest that the focus on susceptibility when producing surveillance data to create empirical treatment guidelines may inadvertently camouflage resistance rates. The findings of this study highlight the need for laboratory-guided treatment of UTIs and ideally a pre-emptive sample should be obtained for laboratory investigation prior to commencement of antimicrobial therapy.

Characteristics of febrile urinary tract infections in older male adults

Background

Urinary tract infections (UTI) are among the most frequent bacterial infections in older adults. The aim of the study was to analyse the existence of differences in clinical features, microbiological data and risk of infection by multidrug-resistant organisms (MDRO) between older and non-older men with febrile UTI (FUTI).

Methods

This was an ambispective observational study involving older males with a FUTI attended in the Emergency Department. Variables collected included age, comorbidity, diagnostic of healthcare-associated (HCA)-FUTI, clinical manifestations, hospitalization, mortality, and microbiological data.

Results

Five hundred fifty-two males with a FUTI, 329 (59.6%) of whom were older adults, were included. Older males had a higher frequency of HCA-FUTI (p <  0.001), increased Charlson scores (p <  0.001), had received previous antimicrobial treatment more frequently (p <  0.001) and had less lower urinary tract symptoms (p <  0.001). Older patients showed a lower frequency of FUTI caused by E. coli (p <  0.001) and a higher rate of those due to Enterobacter spp. (p = 0.003) and P. aeruginosa (p = 0.033). Resistance rates to cefuroxime (p = 0.038), gentamicin (p = 0.043), and fluoroquinolones (p <  0.001) in E. coli isolates and the prevalence of extended-spectrum beta-lactamase and AmpC producing E. coli and Klebsiella spp. strains (p = 0.041) and MDRO (p <  0.001) were increased in older males. Inadequate empirical antimicrobial treatment (p = 0.004), frequency of hospitalization (p <  0.001), and all cause in-hospital mortality (p = 0.007) were higher among older patients. In the multivariate analysis, being admitted from an long term care facility (OR 2.4; 95% CI: 1.06–5.9), having a urinary tract abnormality (OR 2.2; 95% CI: 1.2–3.8) and previous antimicrobial treatment (OR 3.2; 95% CI: 1.9–5.4) were associated to FUTI caused by MDRO.

Conclusions

Older male adults with a FUTI have different clinical characteristics, present specific microbiological features, and antimicrobial resistance rates. In the multivariate analysis being an older male was not associated with an increased risk of FUTI caused by MDRO.

Treatment of urinary tract infections in the era of antimicrobial resistance and new antimicrobial agents

Urinary tract infections (UTIs) caused by antibiotic-resistant Gram-negative bacteria are a growing concern due to limited treatment options. Knowledge of the common uropathogens in addition to local susceptibility patterns is essential in determining appropriate empiric antibiotic therapy of UTIs. The recommended first-line empiric antibiotic therapy for acute uncomplicated bacterial cystitis in otherwise healthy adult nonpregnant females is a 5-day course of nitrofurantoin, a 3-g single dose of fosfomycin tromethamine, or a 5-day course of pivmecillinam. High rates of resistance for trimethoprim-sulfamethoxazole and ciprofloxacin preclude their use as empiric treatment of UTIs in several communities, particularly if patients who were recently exposed to them or in patients who are at risk of infections with extended-spectrum β-lactamases (ESBLs)-producing Enterobacteriales. Second-line options include oral cephalosporins such as cephalexin or cefixime, fluoroquinolones and β-lactams, such as amoxicillin-clavulanate. Current treatment options for UTIs due to AmpC- β -lactamase-producing Enterobacteriales include nitrofurantoin, fosfomycin, pivmecillinam, fluoroquinolones, cefepime, piperacillin-tazobactam and carbapenems. Treatment oral options for UTIs due to ESBLs-E coli include nitrofurantoin, fosfomycin, pivmecillinam, amoxicillin-clavulanate, finafloxacin, and sitafloxacin while pivmecillinam, fosfomycin, finafloxacin, and sitafloxacin are treatment oral options for ESBLs- Klebsiella pneumoniae. Parenteral treatment options for UTIs due to ESBLs-producing Enterobacteriales include piperacillin-tazobactam (for ESBL-E coli only), carbapenems including meropenem/vaborbactam, imipenem/cilastatin-relebactam, and sulopenem, ceftazidime-avibactam, ceftolozane-tazobactam, aminoglycosides including plazomicin, cefiderocol, fosfomycin, sitafloxacin, and finafloxacin. Ceftazidime-avibactam, meropenem/vaborbactam, imipenem/cilastatin-relebactam, colistin, fosfomycin, aztreonam and ceftazidime-avibactam, aztreonam and amoxicillin-clavulanate, aminoglycosides including plazomicin, cefiderocol, tigecycline are treatment options for UTIs caused by carbapenem-resistant Enterobacteriales (CRE). Treatment options for UTIs caused by multidrug resistant (MDR)-Pseudomonas spp. include fluoroquinolones, ceftazidime, cefepime, piperacillin-tazobactam, carbapenems including imipenem-cilastatin/relebactam, meropenem, and fosfomycin, ceftolozane-tazobactam, ceftazidime-avibactam, aminoglycosides including plazomicin, aztreonam and ceftazidime-avibactam, cefiderocol, and colistin. It is important to use the new antimicrobials wisely for treatment of UTIs caused by MDR-organisms to avoid resistance development.

Lower Urinary Tract Infections: Management, Outcomes and Risk Factors for Antibiotic Re-prescription in Primary Care

BACKGROUND

Urinary tract infections (UTIs) are major drivers of antibiotic prescribing in primary care. Inappropriate antibiotic prescribing for UTIs likely drives antibiotic resistance. We aimed to describe current investigation and antibiotic treatment to examine opportunities for improved antimicrobial stewardship.

METHODS

We identified a cohort of all patients with lower UTI diagnosis between 2011 and 2015 in the 390 primary care practices contributing data to ResearchOne in England. We examined investigation, antibiotic treatment and antibiotic re-prescription within 28 days according to guideline-defined patient groups. We assessed risk factors for re-prescription using mixed-effect logistic regression.

FINDINGS

In total, 494,675 UTIs were diagnosed in 300,354 patients. Median age was 54 years, and 83.3% were women. Same-day antibiotic was prescribed for 85.7% of UTIs; 56.8% were treated with trimethoprim, and urine sampling was undertaken in 25.0%. The antibiotic re-prescription rate was low (17,430, 4.1%) and increased slightly over time in men (from 5.2% in 2011 to 6.2% in 2015). Overall, 21.1% of pre-prescription were for the same antibiotic. The percentage of adults with recurrent UTIs ranged from 1.0% in 18-64 year-old men to 2.6% in women ≥ 65 years. The risk of antibiotic re-prescription increased with age, calendar year, recent antibiotic prescribing and treatment with antibiotic other than trimethoprim or nitrofurantoin.

INTERPRETATION

Most patients diagnosed with lower UTI in primary care receive same-day empirical antibiotics with little diversity in choice of agent. The antibiotic re-prescription rate is low. Microbiological investigation and re-prescription of the same antibiotic given for the initial episode happened in one quarter of UTIs.

FUNDING

UK National Health Service Improvement.

The safety of treatment options for acute bacterial skin and skin structure infections

INTRODUCTION

Acute bacterial skin and skin-structure infections (ABSSSI) may develop in both in-patients and out-patients, possibly with a severe clinical presentation. Since most phase 3 randomized clinical trials have shown non-inferiority in efficacy across different agents, considerations regarding their different safety profiles inevitably play a crucial role in the everyday choice about which of them should be employed for the treatment of ABSSSI.

AREAS COVERED

In this review, the authors discuss the safety profile of different treatment options for ABSSSI.

EXPERT OPINION

The spread of methicillin-resistant Staphylococcus aureus (MRSA) in the last decades has inevitably influenced the therapeutic approach to ABSSSI. Adequate knowledge of the peculiar toxicity profile of each drug active against MRSA is essential for guiding, monitoring and managing adverse events, in turn reducing any unfavorable impact of toxicity on patients' outcomes. In the next five years, potential toxicity will play a critical role in establishing the best available therapy for each specific patient, together with consideration regarding the possibility of avoiding hospitalization or allowing a switch from intravenous to oral therapy and early discharge.

Impact of antibiotic treatment duration on outcomes in older men with suspected urinary tract infection: Retrospective cohort study

PURPOSE

Clinical guidelines recommend at least 7 days of antibiotic treatment for older men with urinary tract infection (UTI). There may be potential benefits for patients, health services, and antimicrobial stewardship if shorter antibiotic treatment resulted in similar outcomes. We aimed to determine if treatment duration could be reduced by estimating risk of adverse outcomes according to different prescription durations.

METHODS

This retrospective cohort study included men aged greater than or equal to 65 years old with a suspected UTI. We compared outcomes in men prescribed 3, 5, 7, and 8 to 14 days of antibiotic treatment in a multivariable logistic regression analysis and 3 versus 7 days in a propensity-score matched analysis. Our outcomes were reconsultation and represcription (proxy for treatment failure), hospitalisation for UTI, sepsis, or acute kidney injury (AKI), and death.

RESULTS

Of 360 640 men aged greater than or equal to 65 years, 33 745 (9.4%) had a UTI. Compared with 7 days, men prescribed 3-day treatment had greater odds of reconsultation and represcription (adjusted OR 1.48; 95% CI, 1.25-1.74) but lower odds of AKI hospitalisation (adjusted OR 0.66; 95% CI, 0.45-0.97). We estimated that treating 150 older men with 3 days instead of 7 days of antibiotics could result in four extra reconsultation and represcriptions and one less AKI hospitalisation. We estimated annual prescription cost savings at around £2.2 million.

CONCLUSIONS

Antibiotic treatment for older men with suspected UTI could be reduced to 3 days, albeit with a small increase in risk of treatment failure. A definitive randomised trial is urgently needed.

Antibiotic management of urinary tract infection in elderly patients in primary care and its association with bloodstream infections and all cause mortality: population based cohort study

OBJECTIVE

To evaluate the association between antibiotic treatment for urinary tract infection (UTI) and severe adverse outcomes in elderly patients in primary care.

DESIGN

Retrospective population based cohort study.

SETTING

Clinical Practice Research Datalink (2007-15) primary care records linked to hospital episode statistics and death records in England.

PARTICIPANTS

157 264 adults aged 65 years or older presenting to a general practitioner with at least one diagnosis of suspected or confirmed lower UTI from November 2007 to May 2015.

MAIN OUTCOME MEASURES

Bloodstream infection, hospital admission, and all cause mortality within 60 days after the index UTI diagnosis.

RESULTS

Among 312 896 UTI episodes (157 264 unique patients), 7.2% (n=22 534) did not have a record of antibiotics being prescribed and 6.2% (n=19 292) showed a delay in antibiotic prescribing. 1539 episodes of bloodstream infection (0.5%) were recorded within 60 days after the initial UTI. The rate of bloodstream infection was significantly higher among those patients not prescribed an antibiotic (2.9%; n=647) and those recorded as revisiting the general practitioner within seven days of the initial consultation for an antibiotic prescription compared with those given a prescription for an antibiotic at the initial consultation (2.2% v 0.2%; P=0.001). After adjustment for covariates, patients were significantly more likely to experience a bloodstream infection in the deferred antibiotics group (adjusted odds ratio 7.12, 95% confidence interval 6.22 to 8.14) and no antibiotics group (8.08, 7.12 to 9.16) compared with the immediate antibiotics group. The number needed to harm (NNH) for occurrence of bloodstream infection was lower (greater risk) for the no antibiotics group (NNH=37) than for the deferred antibiotics group (NNH=51) compared with the immediate antibiotics group. The rate of hospital admissions was about double among cases with no antibiotics (27.0%) and deferred antibiotics (26.8%) compared with those prescribed immediate antibiotics (14.8%; P=0.001). The risk of all cause mortality was significantly higher with deferred antibiotics and no antibiotics than with immediate antibiotics at any time during the 60 days follow-up (adjusted hazard ratio 1.16, 95% confidence interval 1.06 to 1.27 and 2.18, 2.04 to 2.33, respectively). Men older than 85 years were particularly at risk for both bloodstream infection and 60 day all cause mortality.

CONCLUSIONS

In elderly patients with a diagnosis of UTI in primary care, no antibiotics and deferred antibiotics were associated with a significant increase in bloodstream infection and all cause mortality compared with immediate antibiotics. In the context of an increase of Escherichia coli bloodstream infections in England, early initiation of recommended first line antibiotics for UTI in the older population is advocated.

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.