AAP-Recommended Treatment for Pediatric UTI
The American Academy of Pediatrics recommends oral antibiotics for 7-14 days as first-line treatment for most pediatric UTIs, with cephalosporins, amoxicillin-clavulanate, or trimethoprim-sulfamethoxazole selected based on local resistance patterns, reserving parenteral therapy only for toxic-appearing children, those unable to retain oral intake, or infants under 3 months. 1, 2, 3
Route of Administration and Initial Antibiotic Selection
- Oral and parenteral routes are equally efficacious when the child can tolerate oral medications, so base your decision on practical considerations rather than assuming IV is superior 1, 2
- First-line oral options include cephalosporins (cefixime, cephalexin), amoxicillin-clavulanate, or trimethoprim-sulfamethoxazole—choose based on your local antibiogram 1, 2, 3
- Use trimethoprim-sulfamethoxazole only if local resistance rates are <10% for pyelonephritis or <20% for lower UTI 2
- Avoid nitrofurantoin for any febrile UTI or suspected pyelonephritis because it doesn't achieve adequate serum/parenchymal concentrations to treat upper tract disease 2, 3
When to Use Parenteral Therapy
- Reserve IV/IM antibiotics for: toxic appearance, inability to retain oral intake, uncertain compliance, or age <3 months 2, 4
- Ceftriaxone 50 mg/kg IV/IM every 24 hours is the standard parenteral option 2
- Neonates <28 days require hospitalization with ampicillin plus aminoglycoside or third-generation cephalosporin for 14 days total 2, 4
Treatment Duration
- 7-14 days is the recommended duration for febrile UTI/pyelonephritis, with 10 days being most commonly used 1, 2, 3
- Shorter courses (1-3 days) are inferior for febrile UTIs and should never be used 2
- For uncomplicated cystitis in children >2 years, shorter courses of 3-5 days may be comparable to longer courses, though evidence is moderate 2
Imaging Recommendations
- Obtain renal and bladder ultrasound (RBUS) for all febrile infants <2 years with first UTI to detect anatomic abnormalities 1, 2, 3
- Do NOT routinely perform voiding cystourethrography (VCUG) after first UTI 1, 2
- Perform VCUG only if: RBUS shows hydronephrosis/scarring/findings suggesting high-grade VUR or obstruction, OR after a second febrile UTI, OR fever persists >48 hours on appropriate therapy 1, 2
Follow-Up Strategy
- Reassess within 1-2 days to confirm fever resolution and clinical improvement—this is when treatment failures become apparent 2
- Instruct parents to seek prompt medical evaluation (ideally within 48 hours) for any future febrile illness to detect recurrent UTIs early 1, 2
- No routine scheduled visits are necessary after successful treatment of uncomplicated first UTI 2
Critical Pitfalls to Avoid
- Never delay treatment if febrile UTI is suspected—early treatment within 48 hours reduces renal scarring risk by >50% 2
- Always obtain urine culture before starting antibiotics—this is your only opportunity for definitive diagnosis and antibiotic adjustment 1, 2
- Never use bag specimens for culture in non-toilet-trained children—70% specificity results in 85% false-positive rate 2
- Use catheterization or suprapubic aspiration instead 2, 3
- Don't treat for less than 7 days for febrile UTI 2, 3
- Avoid fluoroquinolones as first-line agents due to musculoskeletal safety concerns 2
Antibiotic Prophylaxis
- Continuous antibiotic prophylaxis is NOT routinely recommended after first UTI 1, 2
- The RIVUR trial showed prophylaxis reduced recurrent UTI by ~50% but did not reduce renal scarring 1, 2
- Consider prophylaxis selectively only in high-risk patients with recurrent febrile UTI or high-grade VUR, weighing benefits against resistance risk 2
- Evaluate for bowel/bladder dysfunction (constipation) in children with recurrent UTI—this is a major modifiable risk factor that doesn't require imaging or antibiotics 1