Kidney function and the use of nitrofurantoin to treat urinary tract infections in older women

Recurrent UTI in Women-Risk Factors and Management

Urinary tract infections (UTIs) are common in women; more than 50% of women will be diagnosed with a UTI in her lifetime. Many of these women will go on to develop recurrent UTI. Nevertheless, evidence-based prevention of recurrent UTI is under-utilized. Here, the authors provide detailed practical advice on UTI prevention with a thorough review of the evidence. Non-antibiotic prevention measures discussed include increased fluid intake, vaginal estrogen therapy, methenamine, and cranberry. Antibiotic prophyalxis for carefully selected patients is also discussed.

''Myth Busting in Infectious Diseases'': A Comprehensive Review

Antibiotics have played a pivotal role in modern medicine, drastically reducing mortality rates associated with bacterial infections. Despite their significant contributions, the emergence of antibiotic resistance has become a formidable challenge, necessitating a re-evaluation of antibiotic use practices. The widespread belief in clinical practice that bactericidal antibiotics are inherently superior to bacteriostatic ones lacks consistent support from evidence in randomized controlled trials (RCTs). With the latest evidence, certain infections have demonstrated equal or even superior efficacy with bacteriostatic agents. Furthermore, within clinical practice, there is a tendency to indiscriminately order urine cultures for febrile patients, even in cases where alternative etiologies might be present. Consequently, upon obtaining a positive urine culture result, patients often receive antimicrobial prescriptions despite the absence of clinical indications warranting such treatment. Furthermore, it is a prevailing notion among physicians that extended durations of antibiotic therapy confer potential benefits and mitigate the emergence of antimicrobial resistance. Contrary to this belief, empirical evidence refutes such assertions. This article aims to address common myths and misconceptions within the field of infectious diseases.

Antibiotics for UTI Prevention After Intradetrusor OnabotulinumtoxinA Injections

IMPORTANCE

Urinary tract infections (UTIs) occur in 8.6% to 48.1% of patients after intradetrusor onabotulinumtoxinA injections.

OBJECTIVE

The objective of this study was to evaluate both choice and duration of antibiotic prophylaxis on the incidence of UTI within 30 days after in-office onabotulinumtoxinA injections.

STUDY DESIGN

We included a single-site, retrospective cohort of 305 patients with overactive bladder or bladder pain syndrome receiving postprocedure prophylactic antibiotics for in-office, 100-unit intradetrusor onabotulinumtoxinA injections from 2019 to 2023. Categories of antibiotic prophylaxis compared included (1) nitrofurantoin 100 mg twice daily for 3 days, (2) nitrofurantoin 100 mg twice daily for 5 days, (3) trimethoprim-sulfamethoxazole 160 mg/800 mg twice daily for 3 days, and (4) "other regimens." Primary outcome was incidence of UTI within 30 days. Variables were compared via χ2 test. Crude/adjusted odds were estimated using binary logistic regression.

RESULTS

Incidence of UTI was 10.4% for 3-day nitrofurantoin, 20.5% for 5-day nitrofurantoin, 7.4% for 3-day trimethoprim-sulfamethoxazole, and 25.7% among "other regimens" (P = 0.023). Differences among primary regimens were substantial but not statistically significant: 3-day trimethoprim-sulfamethoxazole had 31% lower odds of UTI versus 3-day nitrofurantoin (odds ratio [OR], 0.689; P = 0.518). Compared with 3-day nitrofurantoin regimen, the 5-day nitrofurantoin regimen had twice the odds of UTI (OR, 2.22; P = 0.088). Those receiving "other regimens" had nearly 3 times the odds of UTI (OR, 2.98; P = 0.018). Results were similar adjusting for age and race. Overall urinary retention rate was 1.97%.

CONCLUSIONS

Prophylactic antibiotic choice and duration of treatment potentially affect UTI incidence after in-office, intradetrusor onabotulinumtoxinA injections. Nitrofurantoin and trimethoprim-sulfamethoxazole for 3 days have the lowest UTI incidence.

Antibiotic Selection and Duration for Catheter-Associated Urinary Tract Infection in Non-Hospitalized Older Adults: A Population-Based Cohort Study

Background

We sought to evaluate the impact of antibiotic selection and duration of therapy on treatment failure in older adults with catheter-associated urinary tract infection (CA-UTI).

Methods

We conducted a population-based cohort study comparing antibiotic treatment options and duration of therapy for non-hospitalized adults aged 66 and older with presumed CA-UTI (defined as an antibiotic prescription and an organism identified in urine culture in a patient with urinary catheterization documented within the prior 90 d). The primary outcome was treatment failure, a composite of repeat urinary antibiotic prescribing, positive blood culture with the same organism, all-cause hospitalization or mortality, within 60 days. We determined the risk of treatment failure accounting for age, sex, comorbidities, and healthcare exposure using log-binomial regression.

Results

Of 4,436 CA-UTI patients, 2,709 (61.1%) experienced treatment failure. Compared to a reference of TMP-SMX (61.9% failure), of those treated with fluoroquinolones, 56.3% experienced failure (RR 0.91, 95% CI: 0.85-0.98) and 60.9% of patients treated with nitrofurantoin experienced failure (RR 1.02, 95% CI: 0.94-1.10). Compared to 5-7 days of therapy (treatment failure: 59.4%), 1-4 days was associated with 69.5% failure (RR 1.15, 95% CI: 1.05-1.27), and 8-14 days was associated with a 62.0% failure (RR 1.05, 95% CI: 0.99-1.11).

Conclusions

Although most treatment options for CA-UTI have a similar risk of treatment failure, fluoroquinolones, and treatment durations ≥ 5 days in duration appear to be associated with modestly improved clinical outcomes. From a duration of therapy perspective, this study provides reassurance that relatively short courses of 5-7 days may be reasonable for CA-UTI.

Variation in Antibiotic Treatment Failure Outcome Definitions in Randomised Trials and Observational Studies of Antibiotic Prescribing Strategies: A Systematic Review and Narrative Synthesis

Antibiotic treatment failure is used as an outcome in randomised trials and observational studies of antibiotic treatment strategies and may comprise different events that indicate failure to achieve a desired clinical response. However, the lack of a universally recognised definition has led to considerable variation in the types of events included. We undertook a systematic review of published studies investigating antibiotic treatment strategies for common uncomplicated infections, aiming to describe variation in terminology and components of the antibiotic treatment failure outcomes. We searched Medline, Embase, and the Cochrane Central Register of Clinical trials for English language studies published between January 2010 and January 2021. The population of interest was ambulatory patients seen in primary care or outpatient settings with respiratory tract (RTI), urinary tract (UTI), or skin and soft tissue infection (SSTI), where different antibiotic prescribing strategies were compared, and the outcome was antibiotic treatment failure. We narratively summarised key features from eligible studies and used frequencies and proportions to describe terminology, components, and time periods used to ascertain antibiotic treatment failure outcomes. Database searches identified 2967 unique records, from which 36 studies met our inclusion criteria. This included 10 randomised controlled trials and 26 observational studies, with 20 studies of RTI, 12 of UTI, 4 of SSTI, and 2 of both RTI and SSTI. We identified three key components of treatment failure definitions: prescription changes, escalation of care, and change in clinical condition. Prescription changes were most popular in studies of UTI, while changes in clinical condition were most common in RTI and SSTI studies. We found substantial variation in the definition of antibiotic treatment failure in included studies, even amongst studies of the same infection subtype and study design. Considerable further work is needed to develop a standardised definition of antibiotic treatment failure in partnership with patients, clinicians, and relevant stakeholders.

Alkaline Urine in the Emergency Department Predicts Nitrofurantoin Resistance

BACKGROUND

The Proteeae group (i.e., Proteus species, Morganella morganii, and Providencia species) frequently causes urinary tract infections (UTIs) and is generally resistant to nitrofurantoin. Proteeae species can produce urease, which can increase urine pH.

OBJECTIVE

Our aim was to determine whether higher urine pH in the emergency department is associated with nitrofurantoin resistance.

METHODS

A single health system database of emergency department patients aged 18 years and older who received urinalysis between April 18, 2014, and March 7, 2017, was examined using χ² test and multivariable regression analysis.

RESULTS

Of 67,271 urine samples analyzed, 13,456 samples grew a single bacterial species. Urine cultures growing the Proteeae group were associated with significantly more alkaline urine than other bacteriuria cultures (odds ratio [OR] 2.20, 95% confidence interval [CI] 2.06-2.36; p < 0.001). The Proteeae species represented 4.4% of urine samples at pH 5-7, 24.4% at pH 8-9, and 40.0% at pH 9. At urine pH 5-7, 80.4% of urine samples were sensitive to nitrofurantoin; however, this percentage decreased to 66.1% for urine pH 8-9 and 54.6% for urine pH 9. Nitrofurantoin had the highest OR (2.10, 95% CI 1.85-2.39) among cefazolin, ciprofloxacin, and trimethoprim/sulfamethoxazole for bacteriuria sensitive to those antibiotics at urine pH 5-7. At urine pH 8-9 and 9, nitrofurantoin had the lowest OR among the antibiotics: 0.48 (95% CI 0.42-0.54) and 0.31 (95% CI 0.24-0.40), respectively (p < 0.001 for both).

CONCLUSIONS

Urine pH of 8 or higher is associated with high rates of nitrofurantoin resistance.

Prediction of the excited-state reaction channels in photo-induced processes of nitrofurantoin using first-principle calculations and dynamics simulations

The understanding of the photochemistry of antibiotic compounds is important because it gives the direct information on the possible environmental pollution caused by them. Due to their large size, the theoretical studies of their excited-state reactions are rather challenging. In current work, we combined the on-the-fly trajectory surface-hopping dynamics, conical-intersection optimizations and excited-state pathway calculations to study the photochemistry of the trans-isomer of nitrofurantoin, a widely-used drug to treat the urinary tract infections. The dynamics-then-pathway approach was taken. First the trajectory surface hopping dynamics at the state-averaged complete-active-space self-consistent-field (SA-CASSCF) level with small active space and small basis sets were run. Second, the minimum-energy conical-intersection optimizations were performed. Finally the excited pathways from the Frank-Condon region to different reaction channels were built at the multi-state multi-reference second-order perturbation (MS-CASPT2) level with large active space and large basis set. Several possible channels responsible for the photo-induced reaction mechanism of the trans-nitrofurantoin were obtained, including the cleavage of the NO bond of the NO₂ moiety, the photoisomerization at the central CN bond, and other internal conversion channels. Our findings give some preliminary explanations on available experimental observations. It is also demonstrates that the current theoretical approach is a powerful tool to explore the excited-state reactions in the photochemistry of media-sized or large-sized drug compounds.

Predisposition of Blood group Non-secretors to Urinary tract infection with Escherichia coli Anti-microbial Resistance and Acute Kidney Injury

Urinary tract infection (UTI) causes significant renal damage and disease severity is compounded by antimicrobial resistance (AMR) and other comorbidities in the patient. Blood group antigens secreted in body fluids (secretor status) are known to play a role in bacterial adhesion and we studied its influence on AMR in UTI. A total of 2758 patients with UTI were studied with urine culture, qualitative and semiquantitative urine microscopy, serum creatinine and secretor status in saliva samples by adsorption-inhibition method. Of these, AMR from 300 patients with E. coli infection were assessed as per CLSI 2019 guidelines and extended-spectrum beta-lactamase (ESBL) genes (bla TEM, bla CTX-M, bla SHV) and NDM1 genes were studied using TaqMan probes in Real-time polymerase chain reaction. Patients with UTI were followed up for two weeks. Female patients had higher predilection (57%) for E. coli infection while patients with diabetes or non-secretors had none. In our study, ESBL producers were seen in 62% of the E. coli isolates and fosfomycin had 100% susceptibility. Non-secretors were significantly associated with acute kidney injury (AKI), AMR and ESBL genes. Multidrug-resistance (MDR) was noted in 127/160 (79.4%) ESBL and 17/18 (94%) NDM1 gene encoding strains. Quantitative urine microscopy scoring predicted AKI both at presentation and at end of follow up. ESBL producers were common in our study population and non-secretors had a significant association with AMR genes. Urine microscopy scoring system may be a useful tool to predict AKI in patients with UTI.

Predisposition of Blood group Non-secretors to Urinary tract infection with Escherichia coli Anti-microbial Resistance and Acute Kidney Injury

Urinary tract infection (UTI) causes significant renal damage and disease severity is compounded by antimicrobial resistance (AMR) and other comorbidities in the patient. Blood group antigens secreted in body fluids (secretor status) are known to play a role in bacterial adhesion and we studied its influence on AMR in UTI. A total of 2758 patients with UTI were studied with urine culture, qualitative and semiquantitative urine microscopy, serum creatinine and secretor status in saliva samples by adsorption-inhibition method. Of these, AMR from 300 patients with E. coli infection were assessed as per CLSI 2019 guidelines and extended-spectrum beta-lactamase (ESBL) genes (bla TEM, bla CTX-M, bla SHV) and NDM1 genes were studied using TaqMan probes in Real-time polymerase chain reaction. Patients with UTI were followed up for two weeks. Female patients had higher predilection (57%) for E. coli infection while patients with diabetes or non-secretors had none. In our study, ESBL producers were seen in 62% of the E. coli isolates and fosfomycin had 100% susceptibility. Non-secretors were significantly associated with acute kidney injury (AKI), AMR and ESBL genes. Multidrug-resistance (MDR) was noted in 127/160 (79.4%) ESBL and 17/18 (94%) NDM1 gene encoding strains. Quantitative urine microscopy scoring predicted AKI both at presentation and at end of follow up. ESBL producers were common in our study population and non-secretors had a significant association with AMR genes. Urine microscopy scoring system may be a useful tool to predict AKI in patients with UTI.

Adherence to guideline recommendations for urinary tract infections in adult women: a cross-sectional study

AIM

To study whether changes in drug preferences in the Dutch guideline for the treatment of Urinary Tract Infection (UTI) for General Practitioners (GPs) in 2013, resulted in corresponding changes in antibiotic dispensing.

BACKGROUND

For the treatment of uncomplicated UTI, nitrofurantoin remained the first choice, while fosfomycin became the second choice and changed ranks with trimethoprim. For a subsequent febrile UTI, ciprofloxacin became the first choice and changed ranks with amoxicillin/clavulanic acid, co-trimoxazole remained the third choice.

METHODS

In this observational cross-sectional study, routinely collected dispensing data from the Dutch Foundation of Pharmaceutical Statistics from 2012 to 2017 were used. The number of women 18 years and older, treated with one of the guideline antibiotics for uncomplicated UTI and subsequent febrile UTI were analysed annually. Proportions were calculated. Data were stratified for age categories. Failure of uncomplicated UTI treatment was defined as the dispensing of an antibiotic for febrile UTI within 14 days after the dispensing of an antibiotic for uncomplicated UTI.

FINDINGS

Data were available from 81% of all pharmacies in 2012 to 89% in 2017. Percentages of women dispensed nitrofurantoin were relatively stable with 87.4% in 2012 and 84.4% in 2017. Percentages of women dispensed fosfomycin increased from 5.4% in 2012 to 21.8% in 2017, whereas percentages of women dispensed trimethoprim decreased from 17.8% to 8.0%. Within age categories, the percentage of women dispensed fosfomycin increased from 12.4% in women 18-30 years old to 36.7% in women above 80 years old. Percentages of women dispensed antibiotics for febrile UTI remained stable at 5% annually. Percentages of women receiving ciprofloxacin increased from 1.9% in 2012 to 3.3% in 2017, while those receiving amoxicillin/clavulanic acid decreased from 2.9% to 1.8%. New guideline recommendations resulted in corresponding changes in dispensed antibiotics for uncomplicated UTI and subsequent febrile UTI. Drug choices differed for age categories.

Small Molecules with Membrane-Active Antibacterial Activity

This spotlight on application provides a brief overview of our research exploration, focusing on the research of small molecules with membrane-active antibacterial activity that mimic host-defense peptides (HDPs). The development of antimicrobial HDP agents is an emerging research area as they circumvent the potential disadvantages of HDPs. The small molecules are preferable for development due to their low production cost and potential of more practical applications. In recent years, we conducted research on the design of antibacterial agents based on small molecules including hydantoins, acylated reduced amides, biscyclic guanidines, and dimeric alkylamides of lysines. We herein sketch our journey on the exploration of the antimicrobial activity of these few classes of molecules and hopefully share our insight in the future design of small-molecular-weight antibiotic agents with membrane-active activity that mimic HDPs.

Low antimicrobial resistance in general practice patients in Rotterdam, the city with the largest proportion of immigrants in the Netherlands

Antimicrobial resistance (AMR) is an increasing problem. The prevalence of antimicrobial resistance in general practice patients is expected to be relatively high in Rotterdam, the Dutch city with the largest proportion non-Western immigrants. The aim of this study was to assess the prevalence of antibiotic-resistant uropathogens (Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis) in general practices in Rotterdam, and to find a possible association between the prevalence of antibiotic-resistant E. coli and age, gender, and socioeconomic status (SES). A retrospective analysis was performed of urine samples from general practice patients in 2016. The prevalence of AMR in uropathogens was compared with national resistance data, as was the prevalence of highly and multidrug resistant and extended spectrum β-lactamase (ESBL) producing E. coli and K. pneumoniae. Univariate logistic regression was used to study associations between antibiotic-resistant E. coli and age, gender, and SES area score. No clinically relevant differences were observed in the prevalence of antibiotic-resistant uropathogens in Rotterdam compared with the national prevalence. For E. coli and K. pneumoniae, the prevalence was 3.6% for ESBL production (both pathogens together), while the prevalence ranged between 4.2%-5.0% for high resistance and between 1.2%-3.3% for multidrug resistance. Ciprofloxacin-resistant E. coli was significantly associated with higher age. Although Rotterdam has a high percentage of non-western immigrants and a low SES, AMR is low among general practice patients. This indicates that adherence to national guidelines in general practice enables maintenance of low AMR, even in high-risk populations.

Age-related Trends in Adults with Urinary Tract Infections Presenting to the Emergency Department: A 5-Year Experience

INTRODUCTION

Urinary tract infections (UTIs) are among the most common bacterial infections, affecting 150 million people worldwide each year. Importantly, the incidence of UTI increases markedly with age. The increasing resistance to empirically prescribed antimicrobial agents complicates the management of this disease. This makes UTI an important issue in increasingly aging population and updated epidemiological investigation is advisable. To understand the epidemiological variation in UTI resistance patterns among differently aged populations, we conducted a retrospective study among patients presenting to the emergency department (ED) of a large tertiary-care hospital in Italy during January 2013 and June 2017.

METHODS

1281 patients who presented with UTI symptoms to the ED, were stratified into four age categories: young adults (18-44 years old;), adults (45-64), the elderly (65-84), and the oldest old (≥ 85). Inclusion criteria were urine collected in ED patients with UTI symptoms and first positive culture from one given patient in a given year.

RESULTS

362 (28.2%) patients had a urine culture with positive result, leading to a total of 459 germs isolated, stratified into four categories: young adults (58 isolates, 12.6%), adults (98, 21.4%), the elderly (174, 37.9%), and the oldest old (129, 28.1%). Escherichia coli represents the 60% of all monomicrobial infections, followed in frequency by Klebsiella pneumoniae (15%), and Enterococcus faecalis (5%). The other 20% of the infections are caused by various germs. The most common association of germs in polymicrobial is E. coli + E. faecalis, accounting for the 28% of all infections. Overall, we found a peak of susceptibility to amoxicillin (AMX) in the oldest old ( 81%), significantly higher compared to young adults (54%), adults (47%) and elderly (35%) (p<0,001). For ciprofloxacin (CIP) there is a greater susceptibility in the young adult (55.5%), but not so marked compared to the other three groups; for fosfomicin (FOS) the susceptibility was greater in the group of adults (60%) compared to young adults, elderly and the oldest old. Also for trimethoprim/ sulfamethoxazole (TMP-SMX) we found greater susceptibility in the adult group (60%), followed by the oldest old (57,6%), young adults (49%) and elderly (47%).

CONCLUSION

Age-related differences in antimicrobial-resistant microorganisms were evident for adults with UTI, and could potentially contribute to the risk of inappropriate empirical therapy in elderly patients. Thus, different empirical antimicrobial regimens should be considered for distinct age groups.

Review of the pharmacokinetic properties of nitrofurantoin and nitroxoline

Nitrofurantoin and nitroxoline are oral antibiotics for the treatment or prophylaxis of acute urinary tract infections. New interest in both these drugs is increasing because of the emergence of resistance to other antibiotics, but knowledge of their pharmacokinetics (PK) is lacking since they were developed before the advent of standardized research for drug approval. The aims of this review were to (i) summarize the PK data reported in the literature and (ii) to identify PK knowledge gaps. The current body of PK knowledge of both drugs appears to be poor and mainly based on old studies. Nitrofurantoin PK values were obtained from studies using many variables, e.g. formulations, crystal sizes and analytical methods, resulting in high interindividual variability in PK parameters and no uniform PK profile. Clinical experience and PK data for nitroxoline are even more limited since the drug is registered in only Germany and a few (Eastern European) countries. Clinical studies in relevant patient populations are needed with commercially available nitrofurantoin and nitroxoline formulations at approved dosing regimens to more fully characterize their PK profiles, and to investigate the influence of patient characteristics on these profiles in order to optimize efficacy and avoid toxicity and emergence of resistance. Only with this updated knowledge and efficacy data from well-structured trials can both drugs maintain their antimicrobial activity against uropathogens.

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.

Urinary tract infections in solid organ transplant recipients: Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

These updated guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review the diagnosis, prevention, and management of urinary tract infections (UTI) in solid organ transplantation, focusing on kidney transplant (KT) recipients. KT recipients have unique risk factors for UTI, including indwelling stents and surgical manipulation of the genitourinary tract. KT recipients experience multi-drug antibiotic-resistant infections-UTI prevention and management strategies must consider risks of antimicrobial resistance. Non-antimicrobial prevention strategies for UTI in KT recipients are reviewed. It is important to recognize that some renal transplant recipients with UTI may primarily present with fever, malaise, leukocytosis, or a non-specific sepsis syndrome without symptoms localized to the urinary tract. However, asymptomatic bacteriuria (AB) must be distinguished from UTI because AB is not necessarily a disease state. Accumulating data indicate that there are no benefits of antibiotics for treatment of AB in KT recipients more than 2 months after post-transplant. Further research is needed on management of AB in the early (<2 months) post-transplant period, prophylaxis for UTI in this era of antibiotic resistance, recurrent UTI, non-antimicrobial prevention of UTI, and uropathogens identified in donor urine and/or preservative fluid cultures.

Nitrofurantoin and fosfomycin for resistant urinary tract infections: old drugs for emerging problems

Uncomplicated urinary tract infection is one of the most common indications for antibiotic use in the community However the Gram-negative organisms that can cause the infection are becoming more resistant to antibiotics

Many multidrug resistant organisms retain susceptibility to two old antibiotics nitrofurantoin and fosfomycin Advantages over newer drugs include their high urinary concentrations and minimal toxicity

Fosfomycin is a potential treatment option for patients with uncomplicated urinary tract infection due to resistant organisms Nitrofurantoin may be more effective and can be used for urinary infections in pregnant women

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.

Diagnosis and treatment of urinary tract infections across age groups

Urinary tract infections are the most common outpatient infections, but predicting the probability of urinary tract infections through symptoms and test results can be complex. The most diagnostic symptoms of urinary tract infections include change in frequency, dysuria, urgency, and presence or absence of vaginal discharge, but urinary tract infections may present differently in older women. Dipstick urinalysis is popular for its availability and usefulness, but results must be interpreted in context of the patient's pretest probability based on symptoms and characteristics. In patients with a high probability of urinary tract infection based on symptoms, negative dipstick urinalysis does not rule out urinary tract infection. Nitrites are likely more sensitive and specific than other dipstick components for urinary tract infection, particularly in the elderly. Positive dipstick testing is likely specific for asymptomatic bacteriuria in pregnancy, but urine culture is still the test of choice. Microscopic urinalysis is likely comparable to dipstick urinalysis as a screening test. Bacteriuria is more specific and sensitive than pyuria for detecting urinary tract infection, even in older women and during pregnancy. Pyuria is commonly found in the absence of infection, particularly in older adults with lower urinary tract symptoms such as incontinence. Positive testing may increase the probability of urinary tract infection, but initiation of treatment should take into account risk of urinary tract infection based on symptoms as well. In cases in which the probability of urinary tract infection is moderate or unclear, urine culture should be performed. Urine culture is the gold standard for detection of urinary tract infection. However, asymptomatic bacteriuria is common, particularly in older women, and should not be treated with antibiotics. Conversely, in symptomatic women, even growth as low as 10² colony-forming unit/mL could reflect infection. Resistance is increasing to fluoroquinolones, beta-lactams, and trimethoprim-sulfamethoxazole. Most uropathogens still display good sensitivity to nitrofurantoin. First-line treatments for urinary tract infection include nitrofurantoin, fosfomycin, and trimethoprim-sulfamethoxazole (when resistance levels are <20%). These antibiotics have minimal collateral damage and resistance. In pregnancy, beta-lactams, nitrofurantoin, fosfomycin, and trimethoprim-sulfamethoxazole can be appropriate treatments. Interpreting the probability of urinary tract infection based on symptoms and testing allows for greater accuracy in diagnosis of urinary tract infection, decreasing overtreatment and encouraging antimicrobial stewardship.

Leveraging Antimicrobial Stewardship in the Emergency Department to Improve the Quality of Urinary Tract Infection Management and Outcomes

BACKGROUND

The complex and fast-paced emergency department (ED) practice setting presents unique challenges that demand a tailored approach to antimicrobial stewardship. In this article, we describe the strategies applied by 1 institution's antimicrobial stewardship program (ASP) that were successful in improving prescribing practices and outcomes for urinary tract infection (UTI) in the ED.

METHODS

Core strategies included pre-implementation research characterizing the patient population, antimicrobial resistance patterns, prescribing behavior, and morbidity related to infection; collaboration across multiple disciplines; development and implementation of a UTI treatment algorithm; education to increase awareness of the algorithm and the background and rationale supporting it; audit and feedback; and early evaluation of post-implementation outcomes.

RESULTS

We observed a rapid change in prescribing post-implementation with increased empiric nitrofurantoin use and reduced cephalosporin use (P < .05). Our elevation of nitrofurantoin to firstline status was supported by our post-implementation analysis showing that its use was independently associated with reduced 30-day return visits (adjusted odds ratio, 0.547; 95% confidence interval, 0.312-0.960). Furthermore, despite a shift to a higher risk population and a corresponding decrease in antimicrobial susceptibility rates post-implementation, the preferential use of nitrofurantoin did not result in higher bug-drug mismatches while 30-day return visits to the ED remained stable.

CONCLUSIONS

We demonstrate that an outcomes-based ASP can impart meaningful change to knowledge and attitudes affecting prescribing practices in the ED. The success of our program may be used by other institutions as support for ASP expansion to the ED.

Urinary Tract Infection and Asymptomatic Bacteriuria in Older Adults

Urinary tract infections (UTIs) are a significant cause of morbidity among older adults. However, antibiotic prescriptions for clinically suspected UTIs are often inappropriate. Health care providers frequently struggle to differentiate UTI from asymptomatic bacteriuria, particularly in patients presenting with nonspecific symptoms. Patients with baseline cognitive impairments that limit history-taking can be particularly challenging. This article reviews the epidemiology and pathogenesis of UTI in older adults. It discusses an approach to diagnosis and treatment focused on recognizing patients who would likely benefit from antibiotic treatment and on identifying patients for whom empiric antibiotic therapy should not be given.

Antimicrobial Pharmacotherapy Management of Urinary Tract Infections in Pediatric Patients

Objective: To discuss the risk factors, microbial resistance rates, and pharmacotherapy, including antimicrobial choices and medication dosage regimens, for urinary tract infections (UTIs) in pediatric patients. Data Sources: A MEDLINE literature search (1985 to December 2017) was performed using the following keywords and associated medical subject headings: urinary tract infection, antimicrobial, treatment, and children. Study Selection and Data Extraction: Search was conducted to identify clinical trials, systematic reviews, and guidelines. Search was filtered to include studies with age range between birth and 18 years and published in English. Additional references were identified from selected review articles. Data Synthesis: In total, 27 studies investigating microbial resistance, 31 studies assessing antimicrobial efficacy, 34 studies describing prophylaxis, and 6 systematic reviews were included. The resistance patterns differed across age groups and affected the choice of empirical therapy. If pyelonephritis is suspected, empiric antimicrobials should have high urinary and sufficient parenchymal concentrations. Nitrofurantoin has low microbial resistance rates and can generally be used empirically for treating uncomplicated cystitis in children >1 month of age. Trimethoprim-sulfamethoxazole resistance has increased and should be avoided unless local susceptibility data are available. Certain patients with recurrent UTIs or renal abnormalities may require antimicrobial prophylaxis, which may be associated with adverse effects, such as intolerability or an increased risk of microbial resistance. Conclusion: The resistance pattern of uropathogens should be considered prior to initiating therapy. Controlled trials with large samples are needed to compare the treatment duration of various antimicrobial regimens and the specific role of prophylactic antimicrobials.

Membrane-Active Hydantoin Derivatives as Antibiotic Agents

Hydantoin (imidazolidinedione) derivatives such as nitrofurantoin are small molecules that have aroused considerable interest recently due to their low rate of bacterial resistance. However, their moderate antimicrobial activity may hamper their application combating antibiotic resistance in the long run. Herein, we report the design of bacterial membrane-active hydantoin derivatives, from which we identified compounds that show much more potent antimicrobial activity than nitrofurantoin against a panel of clinically relevant Gram-positive and Gram-negative bacterial strains. These compounds are able to act on bacterial membranes, analogous to natural host-defense peptides. Additionally, these hydantoin compounds not only kill bacterial pathogens rapidly but also prevent the development of methicillin-resistant Staphylococcus aureus (MRSA) bacterial resistance under the tested conditions. More intriguingly, the lead compound exhibited in vivo efficacy that is much superior to vancomycin by eradicating bacteria and suppressing inflammation caused by MRSA-induced pneumonia in a rat model, demonstrating its promising therapeutic potential.

How Common Are Pulmonary and Hepatic Adverse Effects in Older Adults Prescribed Nitrofurantoin?

OBJECTIVES

To determine the frequency of serious pulmonary and hepatic adverse events (AEs) in persons aged 65 and older prescribed nitrofurantoin.

DESIGN

Retrospective electronic health record (EHR) audit of nitrofurantoin prescriptions and associated AEs.

SETTING

Urban academic medical center.

PARTICIPANTS

All inpatients and outpatients aged 65 and older prescribed nitrofurantoin from January 1, 2010, to December 31, 2014.

MEASUREMENTS

The number of nitrofurantoin prescriptions and pulmonary and hepatic AEs associated with nitrofurantoin use was acquired by data extraction from EHRs.

RESULTS

Of 3,400 individuals aged 65 and older prescribed nitrofurantoin during the study period, 641 were identified as possibly having one of five targeted symptoms or disease complications (pulmonary and hepatic) associated with nitrofurantoin. After a detailed chart audit, 89% were deemed to have no adverse reaction, 7% had a minor side effect or allergy, and 3.9% met criteria for suspicion of a nitrofurantoin-induced AE, five of whom were rated as being highly suspicious for nitrofurantoin toxicity; four of the five were identified with pulmonary toxicity and one with hepatotoxicity. Four of five of these individuals used nitrofurantoin chronically.

CONCLUSION

Nitrofurantoin was prescribed for 3,400 individuals aged 65 and older during the 5-year study period. Serious side effects appeared to be uncommon, but chronic use appeared to be at greater risk.

An update on the management of urinary tract infections in the era of antimicrobial resistance

Urinary tract infections (UTIs) caused by antibiotic-resistant Gram-negative bacteria are a growing concern due to limited therapeutic options. Gram-negative bacteria, specifically Enterobacteriaceae, are common causes of both community-acquired and hospital acquired UTIs. These organisms can acquire genes that encode for multiple antibiotic resistance mechanisms, including extended-spectrum-lactamases (ESBLs), AmpC- β -lactamase, and carbapenemases. The assessment of suspected UTI includes identification of characteristic symptoms or signs, urinalysis, dipstick or microscopic tests, and urine culture if indicated. UTIs are categorized according to location (upper versus lower urinary tract) and severity (uncomplicated versus complicated). Increasing rates of antibiotic resistance necessitate judicious use of antibiotics through the application of antimicrobial stewardship principles. Knowledge of the common causative pathogens of UTIs including local susceptibility patterns are essential in determining appropriate empiric therapy. The recommended first-line empiric therapies for acute uncomplicated bacterial cystitis in otherwise healthy adult nonpregnant females is a 5-day course of nitrofurantion or a 3-g single dose of fosfomycin tromethamine. Second-line options include fluoroquinolones and β-lactams, such as amoxicillin-clavulanate. Current treatment options for UTIs due to AmpC- β -lactamase-producing organisms include fosfomycin, nitrofurantion, fluoroquinolones, cefepime, piperacillin-tazobactam and carbapenems. In addition, treatment options for UTIs due to ESBLs-producing Enterobacteriaceae include nitrofurantion, fosfomycin, fluoroquinolones, cefoxitin, piperacillin-tazobactam, carbapenems, ceftazidime-avibactam, ceftolozane-tazobactam, and aminoglycosides. Based on identification and susceptibility results, alternatives to carbapenems may be used to treat mild-moderate UTIs caused by ESBL-producing Enterobacteriaceae. Ceftazidime-avibactam, colistin, polymixin B, fosfomycin, aztreonam, aminoglycosides, and tigecycline are treatment options for UTIs caused by carbapenem-resistant Enterobacteriaceae (CRE). Treatment options for UTIs caused by multidrug resistant (MDR)-Pseudomonas spp. include fluoroquinolones, ceftazidime, cefepime, piperacillin-tazobactam, carbapenems, aminoglycosides, colistin, ceftazidime-avibactam, and ceftolozane-tazobactam. The use of fluoroquinolones for empiric treatment of UTIs should be restricted due to increased rates of resistance. Aminoglycosides, colistin, and tigecycline are considered alternatives in the setting of MDR Gram-negative infections in patients with limited therapeutic options.

Prescribing for patients on dialysis

The pharmacokinetics of a drug may be altered in patients with renal impairment who require dialysis. Some drugs are contraindicated. The drug's clearance and therapeutic index determine if a dose adjustment is needed. A lower dose or less frequent dosing may be required. Consult a reference source or the patient's nephrologist before prescribing. Start at a low dose and increase gradually. If possible give once-daily drugs after dialysis.

Low Concordance With Guidelines for Treatment of Acute Cystitis in Primary Care

We found low concordance with the updated 2010 IDSA guidelines for both the choice of drug and duration of therapy for acute cystitis. Interventions to decrease overuse of fluoroquinolones are needed to preserve the antimicrobial efficacy of these important antimicrobials.

Background. The updated 2010 Infectious Diseases Society of America guidelines recommended 3 first-line therapies for uncomplicated cystitis: nitrofurantoin, trimethoprim-sulfamethoxazole (TMP-SMX), and fosfomycin, while fluoroquinolones (FQs) remained as second-line agents. We assessed guideline concordance for antibiotic choice and treatment duration after introduction of the updated guidelines and studied patient characteristics associated with prescribing of specific antibiotics and with treatment duration.

Methods. We used the Epic Clarity database (electronic medical record system) to identify all female patients aged ≥18 years with uncomplicated cystitis in 2 private family medicine clinics in the period of 2011–2014. For each eligible visit, we extracted type of antibiotic prescribed, duration of treatment, and patient and visit characteristics.

Results. We included 1546 visits. Fluoroquinolones were the most common antibiotic class prescribed (51.6%), followed by nitrofurantoin (33.5%), TMP-SMX (12.0%), and other antibiotics (3.2%). A significant trend occurred toward increasing TMP-SMX and toward decreasing nitrofurantoin use. The duration of most prescriptions for TMP-SMX, nitrofurantoin, and FQs was longer than guidelines recommendations (longer durations were prescribed for these agents in 82%, 73%, and 71% of the prescriptions, respectively). No patient or visit characteristic was associated with use of specific antibiotics. Older age and presence of diabetes were independently associated with longer treatment duration.

Conclusions. We found low concordance with the updated guidelines for both the choice of drug and duration of therapy for uncomplicated cystitis in primary care. Identifying barriers to guideline adherence and designing interventions to decrease overuse of FQs may help preserve the antimicrobial efficacy of these important antimicrobials.