Narrow- vs. broad-spectrum antibiotics: No difference in outcome for infants with UTIs
Infants aged 60 days or younger with UTIs caused by Escherichia coli or Klebsiella pneumoniae who were treated with narrow-spectrum antibiotics were no more likely to relapse or require a longer duration of antibiotics than infants who were treated with broad-spectrum agents, according to a retrospective cohort study published in the Journal of the Pediatric Infectious Diseases Society.
“Pediatric practice guidelines for the diagnosis and management of initial UTI in febrile infants and young children aged 2 to 24 months recommend choosing antibiotics on the basis of local antimicrobial susceptibility patterns,” Marisol Fernandez, MD, from the department of pediatric infectious diseases at the University of Texas at Austin Dell Medical School, and colleagues wrote. “Local antibiotic susceptibility data indicate a cephalexin susceptibility rate of 92% in infants aged [younger than] 60 days, a population excluded from the guidelines, which indicates that narrow-spectrum oral antibiotic therapy might be advisable in this population.”
Fernandez and colleagues identified 307 infants admitted to a children’s hospital in Central Texas between 2009 and 2017 with UTIs caused by E. coli or K. pneumoniae who received oral antibiotic treatment. They classified amoxicillin and cephalexin as narrow-spectrum antibiotics, and all others (cefuroxime, amoxicillin-clavulanate, sulfamethoxazole-trimethoprim, cefdinir, cefixime and ciprofloxacin) as broad-spectrum antibiotics. Patients who received nitrofurantoin as an initial oral antibiotic were excluded because it is not recommended for the treatment of urosepsis or pyelonephritis, according to the study.
Among all patients in the cohort, E. coli was isolated as a single organism in 96%. According to the researchers, 92% of all isolates showed susceptibility to at least one narrow-spectrum oral antibiotic.
“Local antibiotic susceptibility data indicate a cephalexin susceptibility rate of 92% in infants aged [younger than] 60 days, a population excluded from the guidelines, which indicates that narrow-spectrum oral antibiotic therapy might be advisable in this population,” the researchers wrote.
At discharge, 53% (n = 162) of patients were prescribed amoxicillin (n = 67) or cephalexin (n = 95), and the rest were prescribed broad-spectrum antibiotics, according to the study.
“We found no significant difference between the two treatment groups according to their demographics, health history, rate of abnormal renal imaging study results, or severity as assessed by the rates of bacteremia, septic appearance, initial white blood cell count, and length of stay,” the researchers wrote.
Broad-spectrum antibiotic use resulted in higher rates of infection resistance compared with narrow-spectrum antibiotic use (14% vs. 2% resistance, respectively; P = .001).
ED readmission rates were similar among children who received narrow-spectrum antibiotics and those who received broad-spectrum agents (3% vs. 2%, respectively), as well among five patients who relapsed within 30 days of discharge (2% vs. 1%, respectively), Fernandez and colleagues wrote.
Rates of bacteremia also were similar among infants discharged with narrow- or broad-spectrum antibiotics (11% vs. 8%, respectively).
The researchers concluded that antimicrobial stewardship improved prescribing practices at their institution.
“The results of our study show that unassociated antimicrobial stewardship interventions such as facility-specific clinical practice guidelines, education, and physician engagement led to increased use of narrow-spectrum antibiotic treatment in the [younger than] 60-day-old cohort,” they wrote. “To sustain antimicrobial stewardship efforts, the UTI treatment guideline has become an integral part of medical resident education.”
The study was limited by its retrospective and single-center design, but the researchers hope “it might lead other facilities to review local susceptibility data and consider making changes in the treatment of uncomplicated UTI in young infants to more narrow-spectrum antibiotics, as appropriate,” they wrote. – by Joe Gramigna
Disclosures: The authors report no relevant financial disclosures.