Safety and efficacy of lomefloxacin versus norfloxacin in the treatment of complicated urinary tract infections

A sequential study of intravenous and oral Fleroxacin for 7 or 14 days in the treatment of complicated urinary tract infections

OBJECTIVE

To compare 1 and 2-weeks of sequential intravenous and oral treatment for complicated urinary tract infection.

DESIGN

Randomized, clinical trial.

SETTING

2 secondary and 1 tertiary care hospital in the Netherlands.

PATIENTS

Patients (54) were randomly assigned, after 3 days Fleroxacin 400 mg iv once daily, to receive oral fleroxacin (400 mg OD,) either during 4 (total 7) days (n = 26), or during 11 (total 14) days (n = 28). Thirty-four patients were evaluable for efficacy. Complicated urinary tract infection was defined as the presence of an anatomical or functional abnormality of the urinary tract, urinary tract instrumentation, patients presenting with clinical signs and symptoms of pyelonephritis or a serious illness such as diabetes mellitus, immunosuppression or renal failure. Complicated urinary tract infection was defined as the presence of an anatomical or functional abnormality of the urinary tract, urinary tract instrumentation, patients presenting with clinical signs and symptoms of pyelonephritis or a serious illness such as diabetes mellitus, immunosuppression or renal failure.

RESULTS

A bacteriological cure was seen in 22 of 34 (65%) patients at 4-6 weeks after therapy. Overall, a favorable bacteriological response was obtained in 26 of 34 (76%) patients. No significant difference could be found among the two dosage groups (7 days: 14 18 = 78 %; 14 days: 12 16 = 75 %).

CONCLUSIONS

Sequential iv and oral treatment with fleroxacin in complicated UTI is a satisfactory treatment modality. Larger trials should be done in a more homogeneous population, studying shorter treatment durations in complicated UTI.

Pharmacokinetic Characteristics of Antimicrobials and Optimal Treatment of Urosepsis

Urosepsis accounts for approximately 25% of all sepsis cases and may develop from a community-acquired or nosocomial urinary tract infection (UTI). Nevertheless, the underlying UTI is almost exclusively a complicated one with involvement of the parenchymatous urogenital organs (e.g. kidneys, prostate) and mostly associated with any kind of obstructive uropathy. If urosepsis originates from a nosocomial infection, a broad spectrum of Gram-negative and Gram-positive pathogens have to be expected, which are often multiresistant. In urosepsis, as in other types of sepsis, the severity of sepsis depends mostly upon the host response. The treatment of urosepsis follows the generally accepted rules of the 'Surviving Sepsis' campaign guidelines. Early normalisation of blood pressure and early adequate empirical antibacterial therapy with optimised dosing are equally important to meet the requirements of early goal-directed therapy. In most cases of urosepsis, early control of the infectious focus is possible and as important. Optimal supportive measures need to follow the early phase of resuscitation. To lower mortality from urosepsis, an optimal interdisciplinary approach between intensive care, anti-infective therapy and urology is essential, assisted by easy access to the necessary laboratory and imaging diagnostic procedures. Although most antibacterials achieve high urinary concentrations, there are several unique features of complicated UTI, and thus urosepsis, that influence the activity of antibacterial substances: (i) renal pharmacokinetics differ in unilateral and bilateral renal impairment and in unilateral and bilateral renal obstruction; (ii) variations in pH may influence the activity of certain antibacterials; and (iii) biofilm infection is frequently found under these conditions, which may increase the minimal inhibitory concentrations (MIC) of the antibacterials at the site of infection by several hundred folds. Assessment of antibacterial pharmacodynamic properties in such situations should take into account not only the MIC as determined in vitro and the plasma concentrations of the free (unbound) drug, which are the guiding principles for many infections, but also the actual renal excretion and urinary bactericidal activity of the antibacterial substance. In the treatment of urosepsis, it is important to achieve optimal exposure to antibacterials both in plasma and in the urinary tract. The role of drugs with low renal excretion rates is therefore limited. Since urosepsis quite often originates from catheter-associated UTI and urological interventions, optimal catheter care and optimal strategies to prevent nosocomial UTI may be able to reduce the frequency of urosepsis.

Current challenges in the treatment of complicated urinary tract infections and prostatitis

Serious urinary tract infections (UTIs) and acute bacterial prostatitis in adults cause significant morbidity and economic burden. Chronic bacterial prostatitis is a rather rare condition seen in urological practice, however, in certain occasions difficult to treat. In this paper, we review the bacterial etiologies and the resistance patterns found in adults with serious UTIs and bacterial prostatitis, and discuss considerations for selecting optimal antimicrobial therapy. The role of fluoroquinolones as targeted therapy for serious UTIs is highlighted. The use of effective antimicrobial therapy is the foundation of management of serious UTIs and bacterial prostatitis. Selection of the optimal antimicrobial agent must take into account patient-specific factors; infection characteristics (e.g., severity, community- vs. institutional- or hospital-acquired, need for IV agent, UTI, prostatitis); local resistance pattern; pharmacokinetic and pharmacodynamic principles; and cost. Fluoroquinolones are among the alternatives for empirical antibiotic treatment of serious UTIs and acute bacterial prostatitis. In serious UTIs activity of the antimicrobial agent against Pseudomonas aeruginosa needs to be taken into account. In chronic bacterial prostatitis fluoroquinolones are the first choice because of their favourable pharmacokinetic properties at the site of infection. Targeted antimicrobial therapy--emphasising the correct antibacterial spectrum and correct dosage--is likely to provide important benefits, such as reduced morbidity and associated costs, reduced emergence of resistance and maintenance of class efficacy.

Role of fluoroquinolones in the treatment of serious bacterial urinary tract infections

Serious urinary tract infections (UTIs) in adults--defined as acute complicated UTIs or pyelonephritis requiring initial intravenous antimicrobials and/or hospitalisation and nosocomial infections--cause significant morbidity and economic burden. In the US, UTIs are responsible for nearly 7 million outpatient physician office visits, 1 million emergency room visits and over 100 000 hospital admissions annually. Complicated UTIs often affect patients with underlying functional, metabolic or anatomical defects of the urinary tract, whereas most nosocomial UTIs (~80%) are related to short- or long-term catheterisation. Serious UTIs are often difficult to treat because infection involves a diverse array of Gram-negative and Gram-positive bacteria, coupled with increasing antimicrobial resistance in some uropathogens, and a higher rate of recurrent infections. Although Escherichia coli remains a common aetiology (< or =60%), other Enterobacteriaceae, Gram-negative bacilli (e.g. Pseudomonas aeruginosa), and Gram-positive bacteria (e.g. Staphylococcus aureus) are frequently isolated. Patients with long-term catheterisation have UTIs typically caused by organisms that produce biofilms making eradication even more difficult. Overall, aetiology and resistance patterns are not predictable for those with serious UTIs, necessitating confirmation by culture and susceptibility testing.Numerous intravenous and oral antimicrobial treatment options are available and the majority of patients with serious UTIs will need initial intravenous therapy because of the possibility of bacteraemia/sepsis or impaired gastrointestinal absorption. Many experts concur that empirical therapy for the institutionalised or hospitalised patient with a serious UTI should include an intravenous antipseudomonal agent because of an increased risk of urosepsis. While state-of-the-art treatment guidelines are lacking for these infections, targeted therapy should be initiated once susceptibility data are known. The use of targeted therapy--emphasising the "correct antibacterial spectrum" and pharmacodynamic superiority--is likely to provide important benefits (e.g. reduced morbidity and associated costs, reduced emergence of resistance). Agents commonly prescribed include aminoglycosides, beta-lactam/beta-lactamase inhibitor combinations, imipenem, advanced-generation cephalosporins and fluoroquinolones. Fluoroquinolones are often recommended when conventional agents have failed or are less desirable (e.g. toxicity/hypersensitivity concerns), or when resistance is high. Several pivotal clinical trials support the use of fluoroquinolones for serious UTIs with most experience garnered with ciprofloxacin, including a new once-daily extended-release tablet formulation.Treatment of patients with serious UTIs remains challenging. Physicians should choose empirical therapy based on patient demographics/medical history, presumed aetiology and local resistance patterns until more definitive guidelines become available.

A practical guide to antimicrobial management of complicated urinary tract infection

Complicated urinary tract infection occurs in the setting of a functionally or structurally abnormal genitourinary tract. Many different abnormalities may lead to a designation of complicated urinary tract infection, and these abnormalities will have different influences on the frequency of infection and likelihood of relapse or reinfection. The microbiology of complicated urinary tract infection is characterised by a greater variety of organisms and increased likelihood of antimicrobial resistance compared with acute uncomplicated urinary tract infection. Appropriate management requires a urine specimen for culture prior to institution of antimicrobial therapy, and ensuring that the underlying abnormality is fully characterised to determine whether it can be corrected. A wide variety of antimicrobial agents are effective for treatment, and are usually given for 7 to 14 days. If the underlying abnormality can be corrected, subsequent infections may be prevented. However, if the underlying abnormality cannot be corrected a high recurrence rate of infection, approaching 50% by 4 to 6 weeks, is expected. Further study of complicated urinary tract infection is necessary, including determination of when asymptomatic bacteriuria warrants treatment, and exploration of nonantimicrobial approaches to management.

A practical guide to the management of complicated urinary tract infection

Complicated urinary tract infections are infections in the setting of structural or functional abnormalities of the genitourinary tract. They encompass a wide variety of clinical syndromes and anticipated outcomes. The infecting micro-organisms isolated are more varied and demonstrate a higher prevalence of antimicrobial resistance in complicated compared to uncomplicated urinary tract infections. The usual duration of therapy is 7 to 14 days, although comparative trials to define optimal treatment duration are lacking. Long term success of antimicrobial treatment is dependent upon whether or not the underlying genitourinary abnormality can be corrected. Treatment of complicated urinary tract infections will usually be successful and may be permanent if the underlying abnormality can be corrected. If the underlying abnormality cannot be corrected, failure rates of 50% at 4 to 6 weeks following therapy are expected. Antimicrobial agents are similar to those used to treat uncomplicated urinary tract infection. Certain agents, such as nitrofurantoin, should be avoided for individuals with renal failure. No specific agent or class of agents has consistently demonstrated greater therapeutic efficacy where the infecting organism is susceptible to the given agent.