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Advances in the Understanding and Treatment of Complicated Urinary Tract Infections
resistance patterns is encouraged. Knowledge of prior antimicrobial of this review, the issue of treatment of asymptomatic bacteriuria
therapy must also be taken into account when selecting empirical deserves mention. Evidence-based guidelines for treatment of
therapy for patients with complicated UTIs. For example, it has been asymptomatic bacteriuria have been published by the Infectious
demonstrated that an important risk factor for infection with a Diseases Society of America (IDSA) and urologists are urged to be
ciprofloxacin-resistant E. coli is prior therapy with this agent in the familiar with the conditions for which screening and treatment of
months proceeding the infection.
asymptomatic bacteriuria have been shown to be beneficial to
Treatment of asymptomatic bacteriuria in conditions for
The emergence of Enterobacteriaciae, mainly E. coli and Klebsiella which there is no evidence of benefit should be strongly discouraged
species, that produce ESBLs is one of the fastest growing antimicrobial since it may serve as an important factor in the selection of
resistance problems among Gram-negative organisms. These isolates antimicrobial resistance.
are resistant to third- and fourth-generation cephalosporins and are
frequently resistant to other antimicrobial classes, including Conclusion
aminogylcosides and fluoroquinolones. Community-onset UTIs due to Patients with complicated UTIs are a diverse group of individuals with
ESBL-producing E. coli have been described.
Risk factors for infection a wide spectrum of underlying conditions and severity of illness;
with these pathogens are poorly defined at the present time. therefore, a single approach to the management of complicated UTIs
Management of these infections is particularly challenging since
carbapenems are the only antibiotic class predictably active against these
isolates, and therefore oral therapy is not possible. Fosfomycin has been
It is imperative that antimicrobial
shown to have in vitro activity against these isolates, and one non-
randomised study has suggested clinical efficacy; however, further therapy, while usually initiated
studies are needed.
empirically, be adjusted on the basis
In addition to choice of antimicrobial, the duration of antimicrobial
of culture and susceptibility data.
therapy is an important consideration in the management of
complicated UTIs. Once again, a single recommendation is not possible
for all infections. Clearly, longer courses of therapy are required for is not possible. It is imperative that antimicrobial therapy, while usually
complicated infections than for acute uncomplicated cystitis; infections initiated empirically, be adjusted on the basis of culture and
associated with complicating factors that cannot be reversed will require susceptibility data. More data are required regarding the epidemiology
a longer duration of therapy than those associated with a complicating of complicated UTIs, and further understanding of the pathogenesis of
factor that is easily eliminated (e.g. removal of an indwelling catheter). these infections will require specific study of the individual patient
Longer durations of therapy will result in increased cost, increased populations. Data from epidemiological studies, as well as better
potential for toxicity and adverse effects and, possibly, increased chance understanding of pathogenesis, will be essential for efforts to reduce
of selection of antimicrobial-resistant pathogens. At present, the incidence of complicated UTIs. The factor that has the biggest
recommendations regarding duration of antimicrobial therapy in influence on the selection of therapy is antimicrobial resistance.
complicated UTIs are mainly based on expert opinion and therapy While we have emphasised the importance of collaborations with
duration must be individualised for each patient, balancing the risk of an infectious diseases expert in the management of these infections,
relapse (which will undoubtedly result in increased costs) against the we agree with Naber and Krieger that the urologist plays a key role in
risks of more prolonged antimicrobial therapy. the successful management of patients with complicated UTIs.
Clearly, collaboration between disciplines in terms of both research
While a comprehensive discussion regarding the prevention of and patient management will be essential for optimal outcomes for
antimicrobial resistance in complicated UTIs is clearly beyond the scope our patients. ■
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