1572. Cephalexin for Outpatient Urinary Tract Infections in Children
Session: Poster Abstract Session: Clinical Infectious Diseases: UTIs
Saturday, October 10, 2015
Room: Poster Hall

In June 2011, our institution recommended cephalexin as first-line therapy for uncomplicated, outpatient urinary tract infection (UTI) based on review of susceptibility to other first generation cephalosporins. Because the Clinical and Laboratory Standards Institute (CLSI) does not provide interpretive guidelines for direct susceptibility to cephalexin, we evaluated the risk of treatment failure in children with UTI receiving empiric cephalexin.


We included patients age 2 months – 11 years presenting to one of 27 pediatric primary care practices or the Emergency Department from 1/2005 to 9/2013 with a positive urine culture (>100K CFU if clean-catch or >50K CFU if catheterized), pyuria, and signs or symptoms consistent with UTI (fever, dysuria, abdominal or flank pain, urgency, or frequency; in children ≤ 2 years, feeding difficulties, fussiness, or vomiting). We excluded children with comorbid conditions, urologic abnormalities, UTI prophylaxis, or immunosuppression. Treatment failure was defined by switch to an alternate antibiotic within 15 d of urine culture. Analysis included exact binomial confidence intervals and marginal logistic regression. Models accounted for intra-practice correlation and adjusted for age, gender, race, insurance type, and practice type.


Among eligible patients, 761 received empiric cephalexin, 1010 received trimethoprim-sulfamethoxazole (TMP-SMX), and 363 received amoxicillin. Treatment failure occurred in 13% (95% CI 10-15%), 19% (16-21%), and 36% (31-41%) of patients receiving cephalexin, TMP-SMX, and amoxicillin, respectively. In our model, the adjusted odds ratio for treatment failure comparing cephalexin to TMP-SMX was 0.67 (95% CI 0.49 – 0.89). Among cephalexin treated patients who had a pathogen susceptible to cefazolin or cephalothin, 96% had treatment success, similar to that observed in TMP-SMX treated patients with pathogens susceptible to TMP-SMX (95 %).


Empiric cephalexin for treatment of outpatient UTI resulted in fewer treatment failures than TMP-SMX or amoxicillin. Although no direct standard for susceptibility to cephalexin exists, susceptibility to first generation cephalosporins appears to be predictive of treatment success.

Jonathan M. Beus, MD, MS1,2, Carter L. Cowden, MPH1, Talene A. Metjian, PharmD2, Daniele Dona, MD1, Jennifer S. Ngo, BSN1, Evangelos Spyridakis, MD1, Lesli a. Davis, RN1, Kaede V. Sullivan, MD3, Ron Keren, MD, MPH4,5, Jane M. Lavelle, MD6, Kathy N. Shaw, MD, MSCE6 and Jeffrey S. Gerber, MD, PhD1,2, (1)Division of Infectious Diseases, The Children's Hospital of Philadelphia, Philadelphia, PA, (2)Antimicrobial Stewardship Program, The Children's Hospital of Philadelphia, Philadelphia, PA, (3)Department of Pathology and Laboratory Medicine, The Children's Hospital of Philadelphia, Philadelphia, PA, (4)Division of General Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA, (5)Office of Clinical Quality Improvement, The Children's Hospital of Philadelphia, Philadelphia, PA, (6)Division of Emergency Medicine, The Children's Hospital of Philadelphia, Philadelphia, PA


J. M. Beus, None

C. L. Cowden, None

T. A. Metjian, None

D. Dona, None

J. S. Ngo, None

E. Spyridakis, None

L. A. Davis, None

K. V. Sullivan, None

R. Keren, None

J. M. Lavelle, None

K. N. Shaw, None

J. S. Gerber, None

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