What is the recommended treatment for uncomplicated urinary tract infections (UTIs) in children?

Treatment of Uncomplicated UTIs in Children

For uncomplicated UTIs in children, use oral antibiotics for 7-14 days, with first-line options being amoxicillin-clavulanate, trimethoprim-sulfamethoxazole (if local resistance <20%), cephalosporins (cephalexin or cefixime), or nitrofurantoin (for cystitis only, not febrile UTI). 1

Initial Antibiotic Selection Algorithm

Choose empiric therapy based on clinical presentation and local resistance patterns:

• For febrile UTI/pyelonephritis (fever, flank pain, systemic symptoms):

  • First-line oral options: amoxicillin-clavulanate, cephalosporins (cephalexin, cefixime), or trimethoprim-sulfamethoxazole 2, 1
  • Never use nitrofurantoin for febrile UTI as it does not achieve adequate serum/parenchymal concentrations to treat pyelonephritis 1
  • Duration: 7-14 days 1, 3

• For uncomplicated cystitis (dysuria, frequency, urgency without fever):

  • First-line: amoxicillin-clavulanate, trimethoprim-sulfamethoxazole, cephalexin, or nitrofurantoin 2, 1
  • Duration: 3-5 days may be sufficient for cystitis (shorter courses appear comparable to 7-14 days) 1, 4

• Trimethoprim-sulfamethoxazole should only be used if local resistance rates are <20% for lower UTI and <10% for pyelonephritis 2, 1

When to Use Parenteral Therapy

Switch to IV antibiotics for:

• Toxic-appearing children 1, 5
• Age <2-3 months (neonates require hospitalization with ampicillin + aminoglycoside or third-generation cephalosporin for 14 days total) 1, 5
• Unable to retain oral intake or uncertain compliance 1, 5
• No clinical improvement within 48 hours of oral therapy 1

Parenteral options: ceftriaxone, cefotaxime, gentamicin (with or without ampicillin), or piperacillin-tazobactam 2, 1

Specific Dosing Guidance

• Amoxicillin-clavulanate: 40 mg/kg/day divided twice daily 6
• Trimethoprim-sulfamethoxazole: 40 mg/kg sulfamethoxazole + 8 mg/kg trimethoprim per 24 hours, divided every 12 hours 3
• Cefixime: 400 mg daily for adults; weight-based dosing for children 7
• Nitrofurantoin: Use only for uncomplicated cystitis, not for febrile UTI 1

Critical Management Steps

Adjust therapy based on culture results:

• Obtain urine culture before starting antibiotics (catheterization or suprapubic aspiration for non-toilet-trained children; never use bag specimens for culture) 1
• Adjust antibiotics when culture and sensitivity results are available 1
• Consider local antibiotic resistance patterns when selecting empiric therapy 1, 8

Follow-up timing:

• 1-2 days: Clinical reassessment to confirm response to antibiotics and fever resolution 1
• If fever persists beyond 48 hours, reevaluate for treatment failure, antibiotic resistance, or anatomic abnormalities 1

Imaging Recommendations

• Renal and bladder ultrasound (RBUS): Obtain for all febrile infants <2 years with first UTI to detect anatomic abnormalities 1
• Voiding cystourethrography (VCUG): NOT routinely recommended after first UTI 1
• VCUG indicated after: Second febrile UTI, or if RBUS shows hydronephrosis, scarring, or findings suggesting high-grade vesicoureteral reflux or obstruction 1

Common Pitfalls to Avoid

• Do not use nitrofurantoin for febrile UTI/pyelonephritis (inadequate tissue penetration) 1
• Do not treat for <7 days for febrile UTI (shorter courses are inferior for pyelonephritis) 1, 4
• Do not use single-dose amoxicillin (inadequate for uncomplicated cystitis) 4
• Do not delay treatment if febrile UTI is suspected (early treatment may reduce renal scarring risk) 1
• Do not fail to obtain urine culture before starting antibiotics 1
• Do not treat asymptomatic bacteriuria 1

Antibiotic Prophylaxis

• Not routinely recommended after first UTI 1
• Consider selectively only in high-risk patients (recurrent febrile UTI, high-grade vesicoureteral reflux) 1
• The RIVUR trial showed prophylaxis reduced recurrent UTI by ~50% but did not reduce renal scarring 1

Age-Specific Considerations

Neonates (<28 days):

• Require hospitalization and parenteral therapy (ampicillin + aminoglycoside or third-generation cephalosporin) 1
• Complete 14 days total therapy 1

Infants and children ≥2 months:

• Most can be treated with oral antibiotics 1
• Reserve parenteral therapy for toxic appearance, inability to tolerate oral medications, or treatment failure 1, 5