Susceptibility of recent bacterial isolates to cefdinir and selected antibiotics among children with urinary tract infections.

Background: Cefdinir, an extended-spectrum cephalosporin administered orally, is approved by the U.S. Federal Drug Administration for treatment of skin and respiratory tract infections. During the last two years at the authors' institution, this agent has been used as an off-label treatment for urinary tract infections in children.
Objectives: To evaluate antimicrobial susceptibility testing data in children to determine whether there is support for this prescribing practice.
Methods: In this retrospective study (2003-2004), the authors compared the susceptibility patterns of urinary pathogens to cefdinir and selected antibiotics in children who were evaluated for urinary tract infections in an urban tertiary academic pediatric emergency department. Pathogens (community acquired vs. opportunistic or nosocomial) were categorized as susceptible, indeterminate, or resistant on the basis of antibiotic susceptibility breakpoints. The frequency of these categorizations for individual drugs was determined.
Results: Seven hundred five isolates were recovered from urine during the study period. Pathogens isolated most frequently were Escherichia coli, Klebsiella spp, and Proteus spp. Of 431 isolates retained in the data set, 412 (95.6%) were susceptible to cefdinir. This rate was comparable or superior to rates observed for other antibiotics: 49.4% for ampicillin, 84.9% for trimethoprim-sulfamethoxazole, 88.4% for cefazolin, 93.3% for nitrofurantoin, 94.2% for ticarcillin-clavulanate potassium, 97.5% for gentamicin, and 97.7% for ceftriaxone. Cefdinir, however, had lower activity (64.7%) against 17 bacterial isolates categorized as opportunistic or nosocomial pathogens.
Conclusions: Cefdinir provides good coverage against common pathogens responsible for urinary tract infections in children and compares favorably with other oral and parenteral antibiotics that are used in the empiric treatment of this infection.