Treatment of Urinary Tract Infections in Children
Oral antibiotics for 7-14 days are the standard treatment for most pediatric UTIs, with first-line agents including cephalosporins, amoxicillin-clavulanate, or trimethoprim-sulfamethoxazole.
The American Academy of Pediatrics recommends oral antibiotic therapy for 7-14 days for most children with UTIs, reserving parenteral therapy only for toxic-appearing children or those unable to tolerate oral medications 1.
Initial Treatment Selection
First-Line Oral Antibiotics
- Cephalosporins (first or second generation), amoxicillin-clavulanate, or trimethoprim-sulfamethoxazole are appropriate first-line choices 1.
- First-generation cephalosporins show resistance rates of only 9.9% in community settings, making them preferred for empiric treatment 2.
- Amoxicillin-clavulanate demonstrates higher resistance rates (20.7%) and should be used with caution 2.
Dosing Guidelines
- Trimethoprim-sulfamethoxazole: 40 mg/kg sulfamethoxazole and 8 mg/kg trimethoprim per 24 hours, divided every 12 hours 3, 4.
- Amoxicillin-clavulanate: 40 mg/kg/day divided twice daily for 5 days initially 5.
- Treatment must be adjusted based on culture and sensitivity results when available 1.
When to Use Parenteral Therapy
- Reserve IV antibiotics for children who appear toxic, cannot retain oral intake, or have uncertain compliance 1.
- Once stabilized, transition to oral therapy to complete the 7-14 day course 1.
Treatment Duration
Febrile UTI/Pyelonephritis
- 7-14 days total duration is required for febrile UTIs 1.
- Shorter courses (1-3 days) are inferior and should not be used 1.
- For children >2 years with pyelonephritis, 5-9 days may be as effective as 10-14 days, though evidence is limited 1.
Cystitis (Non-Febrile UTI)
- Shorter courses of 3-5 days are comparable to 7-14 days for uncomplicated cystitis 1.
Critical Pitfalls to Avoid
Nitrofurantoin in Febrile UTI
- Never use nitrofurantoin for febrile infants with UTIs 1.
- It does not achieve adequate serum/parenchymal concentrations to treat pyelonephritis 1.
Other Common Errors
- Treating for less than 7 days for febrile UTIs 1.
- Failing to consider local antibiotic resistance patterns 1.
- Not adjusting therapy based on culture results 1.
- Treating asymptomatic bacteriuria 1.
Imaging Recommendations
After First UTI
- Renal and bladder ultrasonography (RBUS) is recommended for all febrile infants with confirmed UTIs to detect anatomic abnormalities 6, 1.
- For children >6 years with first febrile UTI and good response to treatment, imaging is usually not needed 6.
Voiding Cystourethrography (VCUG)
- VCUG should be performed after a second UTI, not routinely after the first 1.
- Consider VCUG if ultrasound reveals hydronephrosis, scarring, or findings suggesting high-grade vesicoureteral reflux (VUR) or obstructive uropathy 1.
Antibiotic Prophylaxis Considerations
Limited Benefit
- Long-term antibiotic prophylaxis shows only modest reduction in recurrent UTI risk (RR 0.68) 6, 7.
- Prophylaxis does not significantly reduce pyelonephritis recurrence regardless of VUR grade 6.
- Most benefit is from reducing cystitis or asymptomatic bacteriuria, which do not cause renal damage 6.
Resistance Concerns
- Prophylactic antibiotics increase resistance risk 2.4-fold 7.
- E. coli resistance to trimethoprim-sulfamethoxazole increased from 19% to 63% in prophylaxis groups 6.
When to Consider Prophylaxis
- Girls aged 12-23 months with grade III-IV VUR showed benefit (number needed to treat = 2.5-3 for 2 years) 6.
- Consider in children with recurrent UTI and anatomic abnormalities 8.
- Typical prophylactic dose: trimethoprim-sulfamethoxazole 2 mg/kg trimethoprim component daily 6.
Age-Specific Considerations
Infants <2 Months
- More conservative imaging approach needed due to higher incidence of renal anomalies and sepsis risk 6.
- Ultrasound is usually appropriate; cystourethrography may be appropriate in boys and with any sonographic abnormalities 6.
Children 2 Months to 6 Years
- Ultrasound is the only imaging usually appropriate after first febrile UTI with good response 6.
Children >6 Years
- Lower prevalence of VUR; imaging role is controversial after first uncomplicated UTI 6.
Follow-Up
- Instruct parents to seek prompt medical evaluation (within 48 hours) for future febrile illnesses to detect recurrent infections early 1.