Association of Adverse Events with Antibiotic Treatment for Urinary Tract Infection

Safety and Tolerability of Pivmecillinam During More Than Four Decades of Clinical Experience: A Systematic Review

The recent US Food and Drug Administration approval of pivmecillinam-an oral prodrug of the amidinopenicillin antibiotic mecillinam-presents a valuable opportunity to address the need for new treatments for uncomplicated urinary tract infection (uUTI). We report findings of a systematic literature review of the safety profile of pivmecillinam/mecillinam based on more than 40 years' experience, mainly in Europe and Canada, to describe its tolerability profile and identify any important safety signals. In total, 110 eligible publications were identified describing use of pivmecillinam/mecillinam as monotherapy or in combination, for treatment of uUTI or other infectious conditions. These studies revealed a benign safety and tolerability profile, awareness of which will inform treatment decisions as pivmecillinam is made available in the United States. Together with the evidence for efficacy of, and minimal resistance to, pivmecillinam, the findings of this review support the position of pivmecillinam as a first-line treatment for uUTI.

Comparative safety of different antibiotic regimens for the treatment of outpatient community-acquired pneumonia among otherwise healthy adults

BACKGROUND

Evidence is limited about the comparative safety of antibiotic regimens for treatment of community-acquired pneumonia (CAP). We compared the risk of adverse drug events (ADEs) associated with antibiotic regimens for CAP treatment among otherwise healthy, non-elderly adults.

METHODS

We conducted an active comparator new-user cohort study (2007-2019) of commercially-insured adults 18-64 years diagnosed with outpatient CAP, evaluated via chest x-ray, and dispensed a same-day CAP-related oral antibiotic regimen. ADE follow-up duration ranged from 2-90 days (e.g., renal failure [14 days]). We estimated risk differences [RD] per 100 treatment episodes and risk ratios using propensity score weighted Kaplan-Meier functions. Ankle/knee sprain and influenza vaccination were considered as negative control outcomes.

RESULTS

Of 145 137 otherwise healthy CAP patients without comorbidities, 52% received narrow-spectrum regimens (44% macrolide, 8% doxycycline) and 48% received broad-spectrum regimens (39% fluoroquinolone, 7% β-lactam, 3% β-lactam + macrolide). Compared with macrolide monotherapy, each broad-spectrum antibiotic regimen was associated with increased risk of several ADEs (eg, β-lactam: nausea/vomiting/abdominal pain [RD per 1000, 3.20; 95% CI, 0.99–5.73]; non–Clostridioides difficile diarrhea [RD per 1000, 4.61; 95% CI, 2.47–6.82]; vulvovaginal candidiasis/vaginitis [RD per 1000, 3.57; 95% CI, 0.87, 6.88]). Narrow-spectrum antibiotic regimens largely conferred similar risk of ADEs. We generally observed similar risks of each negative control outcome, indicating minimal confounding.

CONCLUSIONS

Broad-spectrum antibiotics were associated with increased risk of ADEs among otherwise healthy adults treated for CAP in the outpatient setting. Antimicrobial stewardship is needed to promote judicious use of broad-spectrum antibiotics and ultimately decrease antibiotic-related ADEs.

U.S. primary care physician perceptions on barriers to providing guideline-driven care for UTI and recurrent UTI: a qualitative study

BACKGROUND

Urinary tract infections (UTI) affect almost two-thirds of all women during their lives and many experience recurrent infections. There are evidence-based guidelines from multiple international societies for evaluation and treatment; however, recent claims-based analyses have demonstrated that adherence to these guidelines is poor. This study seeks to understand the barriers experienced by U.S. primary care providers (PCPs) to providing guideline-based care for UTI and recurrent UTI (rUTI).

METHODS

Semi-structured interviews of 18 PCPs, recruited from the greater Los Angeles area, examined real-world clinical management of UTI/rUTI episodes, decisions to refer to subspecialty care, and resources guiding counseling and management. Grounded theory methodology served to analyze interview transcripts and identify preliminary and major themes.

RESULTS

Participants expressed the desire to obtain urine cultures for each cystitis episode, but felt pressured to make compromises by patient demands or barriers to care. PCPs had lower thresholds to empirical treatment if patients had a history of rUTIs, were elderly, or declined evaluation. Laboratory data was minimally utilized in clinical decision-making: urinalyses were infrequently considered when interpreting culture data. PCPs treated a broad set of urologic and non-urologic symptoms as UTI, even with negative cultures. PCPs did not feel comfortable initiating UTI prophylaxis, instead seeking specialist evaluation for anatomic causes. They were unaware of management guidelines, typically utilizing UpToDate® as their primary resource. Few evidence-based UTI prevention interventions were recommended by providers.

CONCLUSIONS

Low availability of succinct and clear professional guidelines are substantial barriers to appropriate UTI/rUTI care. Poor useability of clinical guidance documents results in substantial confusion about the role of preventative measures and additional diagnostic testing. Difficulties in patient access to care providers lead to expectations for presumptive treatment. Future studies are needed to determine if improved educational materials for providers and/or management algorithms can improve guideline concordance of UTI management.

The Impact of Polymerase Chain Reaction Urine Testing on Clinical Decision-Making in the Management of Complex Urinary Tract Infections

While urinary polymerase chain reaction (PCR) testing is effective in organism identification in patients with complex urinary tract infections (cUTI), limited data exists on the clinical usefulness of this test. We serially surveyed physicians treating symptomatic patients with cUTI both at presentation and after PCR, and urine culture (UC) results were available to ascertain how the test results modified the therapy. A total of 96 unique surveys completed by 21 providers were included in the data analysis. The mean age for female and male patients was 69.4 ± 15.5 and 71.6 ± 12.7 years, respectively. The test positivity and line-item concordance for UC and PCR were consistent with prior reports. The PCR results modified or confirmed treatment in 59/96 (61.5%) and 25/96 (26.0%) of the cases, respectively, with 12/29 (41.4%) and 47/67 (70.1%) having negative and positive PCR results, respectively, resulting in treatment change (difference 28.7%, p < 0.01). Of these, 55/59 (57.3%) were alterations in the antibiotic regimen. PCR use to modify treatment was similar across providers and not statistically different when stratified by patient age, gender, or prior empiric therapy. In 31/59 (52.5%) of the cases, the PCR results modified the treatment where UC would not; conversely, UC would have modified the treatment in 3/37 (8.1%) of the cases where PCR did not (difference 44.4%, p < 0.01). We find that PCR test results are used by clinicians in managing cUTI, and use of this test provides an opportunity to improve antibiotic stewardship in this difficult-to-treat subset of patients.

Utilization of broad- versus narrow-spectrum antibiotics for the treatment of outpatient community-acquired pneumonia among adults in the United States

PURPOSE

To characterize antibiotic utilization for outpatient community-acquired pneumonia (CAP) in the United States.

METHODS

We conducted a cohort study among adults 18-64 years diagnosed with outpatient CAP and a same-day guideline-recommended oral antibiotic fill in the MarketScan® Commercial Database (2008-2019). We excluded patients coded for chronic lung disease or immunosuppressive disease; recent hospitalization or frequent healthcare exposure (e.g., home wound care, patients with cancer); recent antibiotics; or recent infection. We characterized utilization of broad-spectrum antibiotics (respiratory fluoroquinolone, β-lactam + macrolide, β-lactam + doxycycline) versus narrow-spectrum antibiotics (macrolide, doxycycline) overall and by patient- and provider-level characteristics. Per 2007 IDSA/ATS guidelines, we stratified analyses by otherwise healthy patients and patients with comorbidities (coded for diabetes; chronic heart, liver, or renal disease; etc.).

RESULTS

Among 263 914 otherwise healthy CAP patients, 35% received broad-spectrum antibiotics (not recommended); among 37 161 CAP patients with comorbidities, 44% received broad-spectrum antibiotics (recommended). Ten-day antibiotic treatment durations were the most common for all antibiotic classes except macrolides. From 2008 to 2019, broad-spectrum antibiotic use substantially decreased from 45% to 19% in otherwise healthy patients (average annual percentage change [AAPC], -7.5% [95% CI -9.2%, -5.9%]), and from 55% to 29% in patients with comorbidities (AAPC, -5.8% [95% CI -8.8%, -2.6%]). In subgroup analyses, broad-spectrum antibiotic use varied by age, geographic region, provider specialty, and provider location.

CONCLUSIONS

Real-world use of broad-spectrum antibiotics for outpatient CAP declined over time but remained common, irrespective of comorbidity status. Prolonged duration of therapy was common. Antimicrobial stewardship is needed to aid selection according to comorbidity status and to promote shorter courses.

Antibiotic Switches in Urinary Tract Infection Are Associated With Atypical Symptoms and Emergent Care

IMPORTANCE

Given worsening global antibiotic resistance, antimicrobial stewardship aims to use the shortest effective duration of the most narrow-spectrum, effective antibiotic for patients with specific urinary symptoms and laboratory testing consistent with urinary tract infection (UTI). Inappropriate treatment and unnecessary antibiotic switching for UTIs harms patients in a multitude of ways.

OBJECTIVE

This study sought to analyze antibiotic treatment failures as measured by antibiotic switching for treatment of UTI in emergent and ambulatory care.

STUDY DESIGN

For this retrospective cohort study, 908 encounters during July 2019 bearing a diagnostic code for UTI/cystitis in a single health care system were reviewed. Urinary and microbiological testing, symptoms endorsed at presentation, and treatments prescribed were extracted from the medical record.

RESULTS

Of 908 patients diagnosed with UTI, 64% of patients (579/908) received antibiotics, 86% of which were empiric. All patients evaluated in emergent care settings were prescribed antibiotics empirically in contrast to 71% of patients in ambulatory settings (P < 0.001). Of patients given antibiotics, 89 of 579 patients (15%, 10% of all 908 patients) were switched to alternative antibiotics within 28 days. Emergent care settings and positive urine cultures were significantly associated with increased antibiotic switching. Patients subjected to switching tended to have higher rates of presenting symptoms inconsistent with UTI.

CONCLUSIONS

Empiric treatment, particularly in an emergent care setting, was frequently inappropriate and associated with increasing rates of antibiotic switching. Given the profound potential contribution to antibiotic resistance, these findings highlight the need for improved diagnostic and prescribing accuracy for UTI.

A Systematic Literature Review on Risk Factors for and Timing of Clostridioides difficile Infection in the United States

INTRODUCTION

Clostridioides difficile infection (CDI) is a major public health threat. Up to 40% of patients with CDI experience recurrent CDI (rCDI), which is associated with increased morbidity. This study aimed to define an at-risk population by obtaining a detailed understanding of the different factors leading to CDI, rCDI, and CDI-related morbidity and of time to CDI.

METHODS

We conducted a systematic literature review (SLR) of MEDLINE (using PubMed) and EMBASE for relevant articles published between January 1, 2016, and November 11, 2022, covering the US population.

RESULTS

Of the 1324 articles identified, 151 met prespecified inclusion criteria. Advanced patient age was a likely risk factor for primary CDI within a general population, with significant risk estimates identified in nine of 10 studies. Older age was less important in specific populations with comorbidities usually diagnosed at earlier age, such as bowel disease and cancer. In terms of comorbidities, the established factors of infection, kidney disease, liver disease, cardiovascular disease, and bowel disease along with several new factors (including anemia, fluid and electrolyte disorders, and coagulation disorders) were likely risk factors for primary CDI. Data on diabetes, cancer, and obesity were mixed. Other primary CDI risk factors were antibiotics, proton pump inhibitors, female sex, prior hospitalization, and the length of stay in hospital. Similar factors were identified for rCDI, but evidence was limited. Older age was a likely risk factor for mortality. Timing of primary CDI varied depending on the population: 2-3 weeks in patients receiving stem cell transplants, within 3 weeks for patients undergoing surgery, and generally more than 3 weeks following solid organ transplant.

CONCLUSION

This SLR uses recent evidence to define the most important factors associated with CDI, confirming those that are well established and highlighting new ones that could help to identify patient populations at high risk.

Defining the Optimal Duration of Therapy for Hospitalized Patients With Complicated Urinary Tract Infections and Associated Bacteremia

BACKGROUND

Limited data are available to guide effective antibiotic durations for hospitalized patients with complicated urinary tract infections (cUTIs).

METHODS

We conducted an observational study of patients ≥18 years at 24 US hospitals to identify the optimal treatment duration for patients with cUTI. To increase the likelihood patients experienced true infection, eligibility was limited to those with associated bacteremia. Propensity scores were generated for an inverse probability of treatment weighted analysis. The primary outcome was recurrent infection with the same species ≤30 days of completing therapy.

RESULTS

1099 patients met eligibility criteria and received 7 (n = 265), 10 (n = 382), or 14 (n = 452) days of therapy. There was no difference in the odds of recurrent infection for patients receiving 10 days and those receiving 14 days of therapy (aOR: .99; 95% CI: .52-1.87). Increased odds of recurrence was observed in patients receiving 7 days versus 14 days of treatment (aOR: 2.54; 95% CI: 1.40-4.60). When limiting the 7-day versus 14-day analysis to the 627 patients who remained on intravenous beta-lactam therapy or were transitioned to highly bioavailable oral agents, differences in outcomes no longer persisted (aOR: .76; 95% CI: .38-1.52). Of 76 patients with recurrent infections, 2 (11%), 2 (10%), and 10 (36%) in the 7-, 10-, and 14-day groups, respectively, had drug-resistant infections (P = .10).

CONCLUSIONS

Seven days of antibiotics appears effective for hospitalized patients with cUTI when antibiotics with comparable intravenous and oral bioavailability are administered; 10 days may be needed for all other patients.

Comparative Safety and Attributable Healthcare Expenditures Following Inappropriate Versus Appropriate Outpatient Antibiotic Prescriptions Among Adults With Upper Respiratory Infections

BACKGROUND

Little is known about the clinical and financial consequences of inappropriate antibiotics. We aimed to estimate the comparative risk of adverse drug events and attributable healthcare expenditures associated with inappropriate versus appropriate antibiotic prescriptions for common respiratory infections.

METHODS

We established a cohort of adults aged 18 to 64 years with an outpatient diagnosis of a bacterial (pharyngitis, sinusitis) or viral respiratory infection (influenza, viral upper respiratory infection, nonsuppurative otitis media, bronchitis) from 1 April 2016 to 30 September 2018 using Merative MarketScan Commercial Database. The exposure was an inappropriate versus appropriate oral antibiotic (ie, non-guideline-recommended vs guideline-recommended antibiotic for bacterial infections; any vs no antibiotic for viral infections). Propensity score-weighted Cox proportional hazards models were used to estimate the association between inappropriate antibiotics and adverse drug events. Two-part models were used to calculate 30-day all-cause attributable healthcare expenditures by infection type.

RESULTS

Among 3 294 598 eligible adults, 43% to 56% received inappropriate antibiotics for bacterial and 7% to 66% for viral infections. Inappropriate antibiotics were associated with increased risk of several adverse drug events, including Clostridioides difficile infection and nausea/vomiting/abdominal pain (hazard ratio, 2.90; 95% confidence interval, 1.31-6.41 and hazard ratio, 1.10; 95% confidence interval, 1.03-1.18, respectively, for pharyngitis). Thirty-day attributable healthcare expenditures were higher among adults who received inappropriate antibiotics for bacterial infections ($18-$67) and variable (-$53 to $49) for viral infections.

CONCLUSIONS

Inappropriate antibiotic prescriptions for respiratory infections were associated with increased risks of patient harm and higher healthcare expenditures, justifying a further call to action to implement outpatient antibiotic stewardship programs.

d-Mannose for Recurrent Urinary Tract Infection Prevention in Postmenopausal Women Using Vaginal Estrogen: A Randomized Controlled Trial

IMPORTANCE

Further research is needed to determine whether d-mannose plus vaginal estrogen therapy (VET) is beneficial over VET alone for recurrent urinary tract infection (rUTI) prevention.

OBJECTIVE

The aim of this study was to evaluate d-mannose efficacy for rUTI prevention in postmenopausal women using VET.

STUDY DESIGN

We conducted a randomized controlled trial comparing d-mannose (2 g/d) with control. Participants were required to have a history of uncomplicated rUTIs and to remain on VET throughout the trial. They were followed up 90 days for incident UTIs. Cumulative UTI incidences were calculated by the Kaplan-Meier method and compared by Cox proportional hazards regression. For the planned interim analysis, P < 0.001 was considered statistically significant. Futility analysis was performed by generating post hoc conditional power for multiple scenarios.

RESULTS

We evaluated 545 patients for frequent/recurrent UTIs from March 1, 2018, to January 18, 2020. Of these women, 213 had culture-proven rUTIs, 71 were eligible, 57 enrolled, 44 began their planned 90-day study period, and 32 completed the study. At interim analysis, the overall cumulative UTI incidence was 46.6%; 41.1% in the treatment arm (median time to first UTI, 24 days) and 50.4% in the control arm (median, 21 days); hazard ratio, 0.76; 99.9% confidence interval, 0.15-3.97. d-Mannose was well tolerated with high participant adherence. Futility analysis suggested the study lacked power to detect the planned (25%) or observed (9%) difference as statistically significant; the study was halted before conclusion.

CONCLUSIONS

d-Mannose is a well-tolerated nutraceutical, but further research is needed to determine whether d-mannose in combination with VET has a significant, beneficial effect beyond VET alone in postmenopausal women with rUTIs.

Candida albicans V132 induces trained immunity and enhances the responses triggered by the polybacterial vaccine MV140 for genitourinary tract infections

Introduction

Recurrent urinary tract infections (RUTIs) and recurrent vulvovaginal candidiasis (RVVCs) represent major healthcare problems all over the world. Antibiotics and antifungals are widely used for such infectious diseases, which is linked with microbial resistances and microbiota deleterious effects. The development of novel approaches for genitourinary tract infections (GUTIs) such as trained immunity-based vaccines (TIbV) is therefore highly required. MV140 is a sublingual whole-cell heat-inactivated polybacterial preparation with demonstrated clinical efficacy for RUTIs. The sublingual heat-inactivated Candida albicans vaccine V132 has been developed for RVVCs. We previously showed that the combination of MV140 and V132 promotes potent Th1/Th17 and regulatory T-cell responses against antigens contained in the formulation and unrelated antigens. The specific contribution of each preparation to such effects and the underlying molecular mechanisms remain incompletely understood.

Methods

PBMC and monocytes were isolated from healthy donors and in vitro stimulated with V132, MV140 or MV140/V132. After 6 days of resting, cells were reestimulated with LPS and MV140. Analysis of cytokine production by ELISA, Seahorse assays for functional metabolic experiments and chromatin immunoprecipitation assays were performed. BALB/c mice were intraperitoneally and sublingually immunized with V132.

Results

We uncover that V132 induces trained immunity in human PBMCs and purified monocytes, significantly increasing the responses triggered by subsequent stimulation with MV140. Mechanistically, V132 drives metabolic rewiring towards increased glycolysis and oxidative phosphorylation and induces epigenetic reprogramming that enhances the transcription of the pro-inflammatory genes IL6 and TNFA. Splenocytes and peritoneal cells from V132-immunize mice show increased responses upon in vitro stimulation with MV140. Remarkably, splenocytes from sublingually V132-immunized and MV140 in vivo treatment mice show stronger Th17 responses than mice exposed to excipients upon in vitro stimulation with MV140.

Conclusion

Overall, we provide novel mechanistic insights into how V132-induced trained immunity enhances both innate and adaptive immune responses triggered by MV140, which might open the door for new interventions for GUTIs with important clinical implications.

A Cost-Effectiveness Analysis of Fosfomycin: A Single-Dose Antibiotic Therapy for Treatment of Uncomplicated Urinary Tract Infection

Nitrofurantoin, trimethoprim-sulfamethoxazole (TMP-SMX) and fosfomycin are first-line therapeutics for uncomplicated urinary tract infections (uUTI). While fosfomycin is the most expensive, it is also attractive due to its effectiveness against most uUTI-causing bacteria, limited risk of cross-resistance with other drugs, and single-dose delivery. In light of these competing attributes, a cost-effectiveness analysis can provide useful, standardized information about tradeoffs between fosfomycin and treatment alternatives. This paper assessed cost-effectiveness via incremental cost-effectiveness ratios (ICERs) that represented a drug’s incremental cost per additional uUTI case resolved with initial course of antibiotic therapy. The study setting was New Hampshire, USA. Total cost of treatment was lowest with TMP-SMX and highest with fosfomycin. ICERs were $84.53 and $78.59 for nitrofurantoin and $2264.29 and $2260.89 for fosfomycin under a payer and societal perspective, respectively. While no standard benchmark for our measure of cost-effectiveness exists, the high national prevalence of antibiotic stewardship efforts suggests that willingness-to-pay to increase the number of people who are successfully treated with an initial course of therapy is non-zero. Ultimately, fosfomycin may currently be considered a cost-effective option for treating uUTI in the US. As a recently off-patent drug, increased competition in the generic market may improve its cost-effectiveness in the future.

Association of Inappropriate Outpatient Pediatric Antibiotic Prescriptions With Adverse Drug Events and Health Care Expenditures

IMPORTANCE

Nonguideline antibiotic prescribing for the treatment of pediatric infections is common, but the consequences of inappropriate antibiotics are not well described.

OBJECTIVE

To evaluate the comparative safety and health care expenditures of inappropriate vs appropriate oral antibiotic prescriptions for common outpatient pediatric infections.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included children aged 6 months to 17 years diagnosed with a bacterial infection (suppurative otitis media [OM], pharyngitis, sinusitis) or viral infection (influenza, viral upper respiratory infection [URI], bronchiolitis, bronchitis, nonsuppurative OM) as an outpatient from April 1, 2016, to September 30, 2018, in the IBM MarketScan Commercial Database. Data were analyzed from August to November 2021.

EXPOSURES

Inappropriate (ie, non-guideline-recommended) vs appropriate (ie, guideline-recommended) oral antibiotic agents dispensed from an outpatient pharmacy on the date of infection.

MAIN OUTCOMES AND MEASURES

Propensity score-weighted Cox proportional hazards models were used to estimate hazards ratios (HRs) and 95% CIs for the association between inappropriate antibiotic prescriptions and adverse drug events. Two-part models were used to calculate 30-day all-cause attributable health care expenditures by infection type. National-level annual attributable expenditures were calculated by scaling attributable expenditures in the study cohort to the national employer-sponsored insurance population.

RESULTS

The cohort included 2 804 245 eligible children (52% male; median [IQR] age, 8 [4-12] years). Overall, 31% to 36% received inappropriate antibiotics for bacterial infections and 4% to 70% for viral infections. Inappropriate antibiotics were associated with increased risk of several adverse drug events, including Clostridioides difficile infection and severe allergic reaction among children treated with a nonrecommended antibiotic agent for a bacterial infection (among patients with suppurative OM, C. difficile infection: HR, 6.23; 95% CI, 2.24-17.32; allergic reaction: HR, 4.14; 95% CI, 2.48-6.92). Thirty-day attributable health care expenditures were generally higher among children who received inappropriate antibiotics, ranging from $21 to $56 for bacterial infections and from -$96 to $97 for viral infections. National annual attributable expenditure estimates were highest for suppurative OM ($25.3 million), pharyngitis ($21.3 million), and viral URI ($19.1 million).

CONCLUSIONS AND RELEVANCE

In this cohort study of children with common infections treated in an outpatient setting, inappropriate antibiotic prescriptions were common and associated with increased risks of adverse drug events and higher attributable health care expenditures. These findings highlight the individual- and national-level consequences of inappropriate antibiotic prescribing and further support implementation of outpatient antibiotic stewardship programs.

Envisioning Future UTI Diagnostics

Urinary tract infections (UTIs) are among the most common bacterial infections in the United States and are a major driver of antibiotic use - both appropriate and inappropriate - across healthcare settings. UTI treatment has become complex due to antibacterial resistance; one quarter of urinary tract isolates of Escherichia coli in the United States in 2017 were resistant to fluoroquinolones and one third to trimethoprimsulfamethoxazole (1), agents with historically predictable activity against E. coli. As a result, more broad-spectrum antibiotics are being used to treat UTIs, contributing to selection of further antibiotic resistance.