Short-term effectiveness of ceftriaxone single dose in the initial treatment of acute uncomplicated pyelonephritis in women. A randomised controlled trial

Cephalosporins for the treatment of uncomplicated pyelonephritis: A systematic review

BACKGROUND

The 2011 Infectious Diseases Society of America and European Society of Clinical Microbiology and Infectious Diseases guidelines recommend ciprofloxacin or sulfamethoxazole-trimethoprim (SMX-TMP) as first-line agents to treat uncomplicated acute pyelonephritis (APN).

OBJECTIVE

With increasing antimicrobial resistance rates and recent changes in practice patterns, the objective of this systematic review was to describe the effectiveness of cephalosporins for uncomplicated APN in more recently published literature.

METHODS

Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were used for reporting. We searched PubMed, Embase, and Scopus for publications between January 2010 and September 2022. Eligible articles detailed patients with uncomplicated APN, treated with first- to fourth-generation cephalosporins, and identified a clinical, microbiological, or health care utilization outcome. Studies with more than 30% of complicated APN patients, non-English-language studies, case reports, case series, pharmacodynamic or pharmacokinetic studies, and in vitro laboratory or animal studies were excluded. Screening, review, and extraction were performed independently by 2 researchers, plus a third for conflict resolution. Critical appraisal of studies was performed using Joanna Briggs Institute checklists.

RESULTS

Eight studies met inclusion, including 5 cohort studies (62.5%), 2 randomized controlled trials (25%), and 1 nonrandomized experimental study (12.5%). Cephalosporins most used across the studies included cefazolin, cephalexin, cefuroxime, cefotaxime, cefdinir, cefditoren, and ceftriaxone. Outcomes assessed were diverse, including clinical or microbiological success and time to defervescence or symptom resolution. Cephalosporins displayed effectiveness for the treatment of acute uncomplicated APN regardless of study design or the presence of a comparison group. No trials reported inferiority of clinical treatment outcomes compared with a fluoroquinolone or SMX-TMP.

CONCLUSION

Cephalosporins may be viable treatment options for the management of uncomplicated APN.

A retrospective review of oral cephalosporins versus fluoroquinolones for the treatment of pyelonephritis

Background

The current Infectious Diseases Society of America guidelines for the treatment of acute uncomplicated pyelonephritis (AUP) advise caution when using oral beta-lactams due to concern for potentially inferior efficacy compared to fluoroquinolones (FQs) and trimethoprim-sulfamethoxazole; however, studies specifically evaluating the efficacy of oral cephalosporins (CPs) in AUP are limited.

Objective

To assess the safety and efficacy of oral CPs versus FQs for the treatment of AUP.

Design, setting and participants

This is a retrospective, chart review study conducted at a single-center, tertiary care hospital.

Measurements

The primary endpoint was treatment failure within 30 days, defined as a change in antibiotic or return to ED or clinic due to persistent symptoms. Secondary endpoints included adverse drug reactions (ADRs) and C. difficile infection (CDI) within 30 days.

Results

Of the 343 patients included in the study, treatment failure occurred in 54/338 (16.0%) patients and was similar between oral CPs and FQs (35/229 [15.3%] vs. 19/109 [17.4%]). A higher percentage of treatment failures were observed for third generation (3GC) and first generation (1GC) CPs compared to second generation CPs (2GC) (3GC: 15/65 [23.4%]; 1GC: 11/49 [22.4%]; 2GC: 9/115 [7.8%]). Documented ADRs were low (6/343 [1.7%]) and no cases of CDI were documented.

Conclusions

Oral CPs appear to be as safe and effective as FQs for the treatment of AUP. Fewer treatment failures were noted with 2GCs as compared to 3GCs and 1GCs.

Intravenous Antibiotic Susceptibility for Urinary Tract Infection Prior to Emergency Department Discharge

Background

Urinary tract infection (UTI) is a common infectious disease managed in the emergency department (ED). Patients may be initially treated with an intravenous (IV) antibiotic and subsequently discharged with an oral antibiotic regimen.

Objective

The purpose of this study was to determine whether the current Infectious Diseases Society of America guideline recommendation for an initial dose of long-acting IV antibiotic for treatment of UTI when the prevalence of fluoroquinolone resistance exceeds 10% improves the likelihood of providing in vitro susceptibility to the isolated uropathogen.

Methods

This was a retrospective study of patients in ED presenting between May 2009 and August 2018 who received treatment for UTI. The primary outcome was susceptibility of uropathogen to the IV antibiotic administered. Secondary outcomes included susceptibility to the oral antibiotic regimen prescribed at discharge, repeat health care visit within 30 days related to UTI follow-up, adverse events (AEs) associated with antibiotic use, and identification of risk factors associated with pathogen resistance.

Results

A total of 255 patients were included for analysis. Of these patients, 230 (90.2%) had pathogens susceptible to the administered IV antibiotic. The oral regimen susceptibility was 81.6% with 29 patients returning for UTI follow-up and 4 patients reporting AEs related to antibiotic use. Men and long-term care facility residents were more likely to have resistant uropathogens.

Conclusion

Administration of a long-acting IV antibiotic for treatment of UTI prior to ED discharge is recommended when the fluoroquinolone resistance rate exceeds 10% to improve in vitro susceptibility coverage.

Oral beta-lactam step down in bacteremic E. coli urinary tract infections

Background

Literature is scarce regarding oral step down to beta-lactams in bacteremic urinary tract infections. Oral fluoroquinolones are an accepted and common step down for bacteremic urinary tract infections; however, their use is associated with mounting safety concerns. We compared clinical cure in patients with E. coli bacteremic urinary tract infections who were stepped down to oral beta-lactams compared to oral fluoroquinolones.

Methods

This multicentre retrospective cohort study included patients with first positive concurrent urine and blood cultures from January 2016 to December 2016. Patients were included if they received empiric intravenous beta-lactam therapy with step down to either oral beta-lactam or fluoroquinolone for treatment completion. The primary outcome was clinical cure. Secondary outcomes were length of hospitalization, all-cause mortality and C. difficile infection. Multivariate analysis and propensity score were used to control for confounding.

Results

A total of 207 patients were identified with bacteremic E.coli urinary tract infections. Clinical cure was achieved in 72/77 (94%) in the oral beta-lactam group versus 127/130 (98%) in the oral fluoroquinolone group (absolute difference − 4.2, 95% confidence interval [CI] -10.3 to 1.9%, p = 0.13). The adjusted odds ratio (OR) for clinical cure with oral beta-lactams was 0.31 (95% CI 0.05–1.90, p = 0.21); propensity score adjusted analysis showed a similar result. There was no statistically significant difference in secondary outcomes.

Conclusions

Oral beta-lactams appear to be a safe and effective step down option in bacteremic E. coli urinary tract infections compared to oral fluoroquinolones.

Oral β-Lactam Antibiotics vs Fluoroquinolones or Trimethoprim-Sulfamethoxazole for Definitive Treatment of Enterobacterales Bacteremia From a Urine Source

Importance

Oral β-lactam antibiotics are traditionally not recommended to treat Enterobacterales bacteremia because of concerns over subtherapeutic serum concentrations, but there is a lack of outcomes data, specifically after initial treatment with parenteral antibiotics. Given the limited data and increasing limitations of fluoroquinolones or trimethoprim-sulfamethoxazole (TMP-SMX), oral β-lactam antibiotics may be a valuable additional treatment option.

Objective

To compare definitive therapy with oral β-lactam antibiotics vs fluoroquinolones or TMP-SMX for Enterobacterales bacteremia from a suspected urine source.

Design, Setting, and Participants

A retrospective cohort study was conducted from January 1, 2007, to September 30, 2015, at 114 Veterans Affairs hospitals among 4089 adults with Escherichia coli, Klebsiella spp, or Proteus spp bacteremia and matching urine culture results. Additional inclusion criteria were receipt of active parenteral antibiotic(s) followed by conversion to an oral antibiotic. Exclusion criteria were previous Enterobacterales bacteremia, urologic abscess, or chronic prostatitis. Data were analyzed from April 15, 2019, to July 26, 2020.

Exposures

Conversion of therapy to an oral β-lactam antibiotic vs fluoroquinolones or TMP-SMX after 1 to 5 days of parenteral antibiotics.

Main Outcomes and Measures

The main outcome was a composite of either 30-day all-cause mortality or 30-day recurrent bacteremia. Propensity-based overlap weights were used to adjust for differences between groups. Log binomial regression models were used to estimate adjusted relative risks (aRRs) and adjusted risk differences (aRDs).

Results

Of the 4089 eligible patients (3731 men [91.2%]; median age, 71 years [interquartile range, 63-81 years]), 955 received an oral β-lactam antibiotic, and 3134 received fluoroquinolones or TMP-SMX. The primary outcome occurred for 42 patients (4.4%) who received β-lactam antibiotics and 94 patients (3.0%) who received fluoroquinolones or TMP-SMX (aRD, 0.99% [95% CI, -0.42% to 2.40%]; aRR, 1.31 [95% CI, 0.87-1.95]). Mortality rates were 3.0% (n = 29) for patients receiving β-lactam antibiotics vs 2.6% (n = 82) for those receiving fluoroquinolones or TMP-SMX (aRD, 0.06% [95% CI, -1.13% to 1.26%]; aRR, 1.02 [95% CI, 0.67-1.56]). Recurrent bacteremia rates were 1.5% (n = 14) among those receiving β-lactam antibiotics vs 0.4% (n = 12) among those receiving fluoroquinolones or TMP-SMX (aRD, 1.03% [95% CI, 0.24%-1.82%]; aRR, 3.43 [95% CI, 0.42-27.90]).

Conclusions and Relevance

In this cohort study of adults with E coli, Klebsiella spp, or Proteus spp bacteremia from a suspected urine source, the relative risk of recurrent bacteremia was not significantly higher with β-lactam antibiotics compared with fluoroquinolones or TMP-SMX, and the absolute risk and risk difference were small (ie, <3%). No significant difference in mortality was observed. Oral β-lactam antibiotics may be a reasonable step-down treatment option, primarily when alternative options are limited by resistance or adverse effects. Further study is needed because statistical power was limited owing to a low number of recurrent bacteremia events.

Appropriateness of Antibiotic Prescriptions for Urinary Tract Infections

Introduction

Urinary tract infections (UTI) are a common indication for antibiotic use in the emergency department (ED). With antibiotic resistance on the rise, it is essential that antibiotics be prescribed appropriately for UTIs. Our objective was to evaluate the appropriateness of antibiotic prescriptions by ED providers for uncomplicated cystitis and pyelonephritis.

Methods

We conducted a retrospective study of females ages 2–50 years seen in an academic ED from January 2017 to April 2018 diagnosed with UTI. We assessed the appropriateness of discharge antibiotic prescriptions, as determined by adherence to clinical practice guidelines, best evidence for the particular indication (cystitis vs pyelonephritis for children and adults), and the local antibiogram.

Results

A total of 421 patients were included in this study. Of these, 60 children and 198 adults were diagnosed with cystitis, and 47 children and 116 adults were diagnosed with pyelonephritis. Treatment in the absence of true infection was common, with culture-confirmed UTI occurring in only 17/50 (34%) of children and 60/129 (47%) of adults diagnosed with cystitis, and 23/40 (58%) of children and 58/87 (67%) of adults diagnosed with pyelonephritis, among patients who had urine cultures. The type of antibiotic prescribed was appropriate in 53/60 (88%) of children and 135/198 (68%) of adults with cystitis, and 38/47 (81%) of children and 53/116 (46%) of adults with pyelonephritis. The most common inappropriate antibiotic types were beta-lactams in adults (n = 92), nitrofurantoin for pyelonephritis (n = 16), and amoxicillin (n = 15). Dosing and duration errors were also common, occurring in 122/279 (44%) of prescriptions of an appropriate antibiotic type. The frequency of errors in the type of antibiotic prescribed was similar among provider types (attending physician, resident physician, and advanced practice clinician; p = 0.926).

Conclusion

This study reveals room for improvement in antibiotic prescription practices across provider cohorts in the ED for the management of uncomplicated cystitis and pyelonephritis in females.

Efficacy of Different Energy Levels Used in Focused and Radial Extracorporeal Shockwave Therapy in the Treatment of Plantar Fasciitis: A Meta-Analysis of Randomized Placebo-Controlled Trials

The objective of this study was to assess the efficacy of different energy levels used in extracorporeal shockwave therapy (ESWT) in the treatment of plantar fasciitis using a systematic review and meta-analysis. We searched PubMed, Embase, and Cochrane library, from inception to March 2019 for randomized controlled trials that compared ESWT with placebo in patients with plantar fasciitis. The risk of bias for selected articles was assessed based on the Cochrane Handbook Systematic Review of Interventions. The pooled data were estimated by the mean difference or odds ratio. The meta-analysis showed that the high-energy ESWT group had a better success rate than the control group only at a three-month follow-up, but no significant difference between groups was observed for the other follow-up visits (1 and 12 months). In addition, no significant differences in visual analog scale (VAS) scores between groups were observed for all the follow-up visits (one-month and three-month). On the contrary, the medium-energy ESWT group had significantly better success rates than the control group for all the follow-up visits (3, 6, and 12 months). In addition, the medium-energy ESWT group had significant improvement in VAS scores compared with the control group for all the follow-up visits (1, 3, 6, and 12 months) after removing the extreme values. The low-energy ESWT group had significant improvement in VAS scores compared with the control group for all the follow-up visits (3 and 12 months). Otherwise, focused ESWT seems to be more effective than radial ESWT when compared with the control group. Use of local anesthesia can reduce the efficacy of low- and high-energy ESWTs. Our meta-analysis suggested that medium-energy ESWT in the treatment of plantar fasciitis was more effective than the control group. A limited number of trials related to low- and high-energy ESWTs were included in our meta-analysis. More research is required to confirm the efficacy of low- and high-energy ESWTs in future studies.

Top Questions in Uncomplicated, Non-Staphylococcus aureus Bacteremia

The Infectious Diseases Society of America infection-specific guidelines provide limited guidance on the management of focal infections complicated by secondary bacteremias. We address the following 3 commonly encountered questions and management considerations regarding uncomplicated bacteremia not due to Staphylococcus aureus: the role and choice of oral antibiotics focusing on oral beta-lactams, the shortest effective duration of therapy, and the role of repeat blood cultures.

Guía de práctica clínica sobre diagnóstico y tratamiento de infección de vías urinarias no complicada en mujeres adquirida en la comunidad

<p class="p1"><span class="s1">Mediante un proceso de adaptación de guías de práctica clínica se seleccionaron y evaluaron guías de infección de vías urinarias en mujeres premenopáusicas no embarazadas; se identificaron 3 de alta calidad. Con base en las evidencias y las recomendaciones aportadas por estas guías, se realizó un consenso para realizar recomendaciones para personal de salud —médicos, personal de laboratorio y enfermeros— sobre el diagnóstico de las infecciones urinarias —cistitis y pielonefritis—, sus tratamientos y prevención de la recurrencia.</span></p>

The efficacy of sequential therapy using pazufloxacin followed by oral fluoroquinolones for treatment of pyelonephritis

The efficacy of sequential therapy of pazufloxacin (PZFX), which is a parenteral fluoroquinolone, followed by oral fluoroquinolones [tosufloxacin tosilate (TFLX) or levofloxacin (LVFX)] for treatment of pyelonephritis, was evaluated. Patients with pyelonephritis who had fever (≥37.5 °C), pyuria (≥10 white blood cells/high-power field), and bacteriuria (≥10(4) colony-forming units/ml) were eligible for this study. PZFX (500 mg) was given intravenously twice a day for at least 3 days. If the patients were clinically improved, TFLX (150 mg) or LVFX (100 mg) was then administered orally three times a day for at least 5 days. Patients underwent clinical and microbiological evaluation at 5-9 days after final drug administration. Clinical and microbiological efficacy could be assessed in 21 of 25 cases enrolled. Both clinical and microbiological efficacy rates were 81.0 % (17/21 cases). In the effective cases, the mean administration time was 4.2 days for PZFX and 6.0 days for oral fluoroquinolones. The mean time to defervescence was 3.4 days for the effective cases. In the four treatment failure cases, three quinolone-resistant Escherichia coli and a quinolone-resistant Enterococcus faecalis were isolated. This sequential therapy seemed to be clinically effective in the treatment of pyelonephritis; however, the prevalence of quinolone-resistant E. coli should be taken into account.

A prospective, randomized, double dummy, placebo-controlled trial of oral cefditoren pivoxil 400mg once daily as switch therapy after intravenous ceftriaxone in the treatment of acute pyelonephritis

OBJECTIVES

To compare the clinical and bacteriological effectiveness of intravenous (IV) ceftriaxone followed by oral cefditoren pivoxil or IV ceftriaxone for acute pyelonephritis.

METHODS

A prospective randomized controlled trial of patients with a presumptive diagnosis of acute pyelonephritis was performed. Daily 2g IV ceftriaxone was initially given to all patients. After day 3, patients who satisfied the criteria for switch therapy were randomized to either group A (IV ceftriaxone) or group B (oral cefditoren pivoxil 400mg once daily).

RESULTS

Eighty-two patients were enrolled; 41 (50%) patients in group A and 41 (50%) patients in group B were evaluated. There was no statistically significant difference in baseline characteristics between the two groups. Clinical cure was observed in 39 of 41 (95.1%) patients in group A and 41 of 41 (100%) patients in group B (p=0.15, 95% confidence interval (CI) -0.12 to 0.02). Urine bacteriological eradication was found in 63.4% in group A and 60% in group B (p=0.75, 95% CI -0.18 to 0.25). There was no statistically significant difference in adverse effects between the two treatment groups.

CONCLUSION

These data suggest that IV ceftriaxone followed by oral cefditoren pivoxil is highly effective and well-tolerated for the treatment of acute pyelonephritis, even for uropathogens with a high proportion of quinolone-resistant strains.

Antibiotic treatment of uncomplicated urinary tract infection in premenopausal women

Uncomplicated urinary tract infections (UTIs) in otherwise healthy premenopausal women are one of the most frequent infections in the community. Therefore any improvement in management will have a high impact not only on the quality of life of the individual patient but also on the health system. In placebo-controlled studies antimicrobial treatment was significantly more effective than placebo, but on the other hand showed more adverse events. The choice of antibiotic depends on the spectrum and susceptibility patterns of the uropathogens, its effectiveness for this indication, its tolerability, its collateral effects and cost. After a systematic literature search, recommendations for empiric treatment of acute uncomplicated cystitis and acute uncomplicated pyelonephritis and for follow-up strategies were developed.

International Clinical Practice Guidelines for the Treatment of Acute Uncomplicated Cystitis and Pyelonephritis in Women: A 2010 Update by the Infectious Diseases Society of America and the European Society for Microbiology and Infectious Diseases

A Panel of International Experts was convened by the Infectious Diseases Society of America (IDSA) in collaboration with the European Society for Microbiology and Infectious Diseases (ESCMID) to update the 1999 Uncomplicated Urinary Tract Infection Guidelines by the IDSA. Co-sponsoring organizations include the American Congress of Obstetricians and Gynecologists, American Urological Association, Association of Medical Microbiology and Infectious Diseases–Canada, and the Society for Academic Emergency Medicine. The focus of this work is treatment of women with acute uncomplicated cystitis and pyelonephritis, diagnoses limited in these guidelines to premenopausal, non-pregnant women with no known urological abnormalities or co-morbidities. The issues of in vitro resistance prevalence and the ecological adverse effects of antimicrobial therapy (collateral damage) were considered as important factors in making optimal treatment choices and thus are reflected in the rankings of recommendations.

The clinical spectrum of acute 'uncomplicated' pyelonephritis from an emergency medicine perspective

Acute uncomplicated pyelonephritis (APN) is a complex clinical entity, which is defined differently based on clinical or imaging criteria. The aim of this study was to describe the clinical and radiological presentation of APN-upper urinary tract infection (UTI) cases observed between May 2005 and June 2006 and hospitalised in the Emergency Medicine ward of San Luigi Hospital, Orbassano, Turin, Italy. All patients underwent imaging scans and were differentiated on the basis of parenchymal involvement. Of around 45000 patient visits to the emergency room between May 2005 and June 2006, 23 patients were diagnosed as having uncomplicated upper UTI (all female, age 15-57 years). Renal parenchymal involvement was confirmed by imaging in 16 cases (69.6%). The imaging spectrum ranged from a small single lesion to large multiple defects; on admission, 2 cases had no pain and 2 had no fever; lower urinary tract symptoms were present in only 13 patients (7 with parenchymal involvement). All patients with parenchymal involvement had at least one sign of systemic inflammation-infection. Most patients (15) had taken antibiotics before hospitalisation; consequently, urine cultures were negative in 21 cases (14 cases with positive imaging (87.5%)). The data from patients with and without parenchymal involvement overlapped, the only difference being a higher prevalence of high CRP levels in cases with parenchymal involvement.

Modes of administration of antibiotics for symptomatic severe urinary tract infections

BACKGROUND

Urinary tract infection (UTI), worldwide, is a major source of disease in children and adults. As it may have long-term consequences such as kidney failure and hypertension, it is important to treat patients with UTI adequately. Although standard management of severe UTI usually means intravenous (IV) therapy, at least initially, there are studies showing that oral therapy may also be effective.

OBJECTIVES

To assess whether the mode of administration of antibiotic therapy for severe UTI has an effect on cure rate, reinfection rate and kidney scarring.

SEARCH STRATEGY

The Cochrane Renal Group's specialised register, the Cochrane Central Register of Controlled Trials (CENTRAL, in The Cochrane Library), MEDLINE and EMBASE were searched. No language restriction was applied. Reference lists of relevant articles and reviews were checked for additional studies and authors of relevant articles/abstracts were contacted for further information. Date of last search: July 2007.

SELECTION CRITERIA

All randomised controlled trials (RCTs) comparing different modes of antibiotic application for patients with severe UTI (children and adults) were considered.

DATA COLLECTION AND ANALYSIS

Study quality was assessed and data extracted. Statistical analyses were performed using the random effects model and the results expressed as relative risk (RR) for dichotomous outcomes or mean difference (WMD) for continuous data with 95% confidence intervals (CI).

MAIN RESULTS

Fifteen RCTs (1743 patients) were included. Studies compared oral versus parenteral treatment (1), oral versus switch treatment (initial intravenous (IV) or intramuscular (IM) therapy followed by oral therapy) (5), switch versus parenteral treatment (6) and single dose parenteral followed by oral therapy versus oral (1) or switch therapy (3). There was a variety of short-term and long-term outcomes, but no pooled outcomes showed significant differences. Most included studies were small though and there were few outcomes for combination in a meta-analysis.

AUTHORS' CONCLUSIONS

There is no evidence suggesting that oral antibiotic therapy is less effective for treatment of severe UTI than parenteral or initial parenteral therapy. The results of this review suggest that the mode of application does not determine therapeutic success.

Antibiotic treatment for acute 'uncomplicated' or 'primary' pyelonephritis: a systematic, 'semantic revision'

The definition of acute pyelonephritis is controversial. There are two contrasting approaches: (1) acute pyelonephritis is a severe infectious disease involving the kidney parenchyma, and specific imaging techniques are required for diagnosis; (2) acute pyelonephritis is a urinary tract infection, and diagnosis and therapy follow simplified clinical and laboratory pathways. In this study, recent randomized controlled trials (RCTs) were systematically reviewed and the diagnostic and therapeutic approaches to acute 'uncomplicated' pyelonephritis were analysed. Medline, Embase, Cochrane Central Register of Controlled Trials (CCTR) and Chinal were searched employing Mesh, Emtree and free terms on 'pyelonephritis'. Limits included human, period (1995-2004), and trials-reviews (where available). In total, 904 references and 175 full-text were retrieved; 29 were pertinent RCTs. Seven RCTs were added from reference lists (indexed on urinary tract infections). Imaging examinations were performed in 11 of 14 studies on children (diagnostic requisite in two) and in two studies on adults; scarring was not analysed in adults. Clinical definitions varied widely (fever >37.8 to >39 degrees C, culture titres 10(4) >10(5)). Studies on adults were limited to short-term end-points (microbiological sterilization, clinical improvement). Duration of therapy was 4-20 days. The trend was towards shorter periods of therapy, mainly on an outpatient basis; intravenous therapy, if performed, was usually limited to the first 1-3 days. For acute uncomplicated pyelonephritis, the tendency is towards 2 weeks of mainly oral antibiotic therapy. However, the recent literature on adults does not discriminate among different upper urinary tract infections nor does it provide data on renal scarring. While cost constraints point towards short-term therapies, further studies are needed to assess the prevalence and long-term effect of kidney scars.

Acute pyelonephritis among adults: cost of illness and considerations for the economic evaluation of therapy

Urinary tract infection (UTI) is an infection anywhere in the urinary tract, most commonly due to bacteria. If infection involves the kidney, the UTI is termed acute pyelonephritis (APN). An estimated 10-30% of all patients with APN are hospitalised for treatment; in the US, the incidence of hospitalisation is 11.7 per 10,000 for women and 2.4 per 10,000 for men. Perhaps because of the generally good prognosis of APN when treated with current antibacterial therapies, there have been relatively few studies of patient management and therapeutic options for the disease, or of its epidemiology and risk factors. The most cost-effective outpatient management strategy (immediate discharge, observation followed by discharge, etc.) is currently unknown. Appropriate antimicrobial selection is clearly important, as treatment failures will increase the cost of care and result in additional morbidity for patients. The direct and indirect costs of APN are significant: an estimated 2.14 billion US dollars (year 2000 values). Cost estimates are most sensitive to hospitalisation rates, which are unknown in the US. Additional studies are needed to better define when in-hospital treatment is required. As the pathogens causing APN are increasingly becoming resistant to current therapies, not only are clinical trials in order to test the effectiveness of alternative therapies, but epidemiological studies to identify risk factors for infection with a resistant isolate and effective prevention strategies are required, especially among those with previous episodes of APN.

Antimicrobial Selection in the Treatment of Pyelonephritis

Pyelonephritis is a common clinical entity, although accurate data regarding the true prevalence of this infection are lacking. Acute pyelonephritis is associated with significant morbidity and even mortality. There are very few randomized controlled clinical trials that have addressed the optimal management strategies and antimicrobial therapy for this infection. Increasing resistance among uropathogens, especially Escherichia coli, has impacted recommendations for empiric antimicrobial therapy, and fluoroquinolones have emerged as the empiric therapy of choice for individuals managed as outpatients; more options are available for empiric parenteral therapy for those who require hospitalization. Further study of the epidemiology of antimicrobial resistance among uropathogens and of alternative agents for the management of pyelonephritis is urgently needed.