What is the recommended treatment for urinary tract infections (UTIs) in pediatric patients?

Treatment of Urinary Tract Infections in Pediatric Patients

For febrile UTIs in children aged 2-24 months, initiate treatment with either oral or parenteral antibiotics for 7-14 days based on local resistance patterns, with oral therapy being equally effective as parenteral for most children who can tolerate oral intake. 1

Diagnostic Requirements Before Treatment

• Obtain urine culture by catheterization or suprapubic aspiration before starting antibiotics—bagged specimens are unreliable for culture 1
• A positive culture requires ≥50,000 CFU/mL of a single uropathogen (not Lactobacillus, coagulase-negative staphylococci, or Corynebacterium) 1
• Urinalysis showing pyuria or bacteriuria plus positive culture confirms UTI 1

Route of Administration Decision

Oral therapy is equally efficacious as parenteral therapy for children >3 months with uncomplicated UTI 1, 2

Use Parenteral Therapy When:

• Child appears "toxic" or hemodynamically unstable 1
• Unable to retain oral fluids or medications 1
• Age <2-3 months 3, 4
• Immunocompromised status 3
• Compliance with oral medication is uncertain 1

Empirical Antibiotic Selection

Oral Options (for uncomplicated cases):

• Cephalosporins (first choice based on local resistance):
  • Cefixime: 8 mg/kg/day in 1 dose 1
  • Cefpodoxime: 10 mg/kg/day in 2 doses 1
  • Cephalexin: 50-100 mg/kg/day in 4 doses 1
• Amoxicillin-clavulanate: 20-40 mg/kg/day in 3 doses 1
• TMP-SMX: 6-12 mg/kg trimethoprim + 30-60 mg/kg sulfamethoxazole per day in 2 doses (only if local resistance <20%) 1, 5, 6

Parenteral Options:

• Ceftriaxone: 75 mg/kg every 24 hours (preferred for IV therapy) 1
• Cefotaxime: 150 mg/kg/day divided every 6-8 hours 1
• Gentamicin: 7.5 mg/kg/day divided every 8 hours 1
• Amikacin: Consider for suspected ESBL-producing organisms 7

Critical Caveat:

Do NOT use nitrofurantoin for febrile UTI/pyelonephritis—it does not achieve adequate serum/parenchymal concentrations 1

Treatment Duration

• Febrile UTI/Pyelonephritis: 7-14 days total 1, 2
• Cystitis: 3-5 days for uncomplicated cases 2, 4
• Switch from IV to oral once afebrile for 24-48 hours and clinically improved 1, 4

Age-Specific Considerations

Neonates (<28 days):

• Hospitalize and use ampicillin + cefotaxime or ampicillin + gentamicin parenterally 3, 4
• Complete 14 days of therapy 4

Infants 28 days to 3 months:

• If clinically ill: hospitalize with parenteral 3rd generation cephalosporin or gentamicin 4
• If not acutely ill: outpatient management with daily ceftriaxone or gentamicin until afebrile 24 hours, then complete 14 days with oral antibiotics 4

Children >3 months:

• Oral therapy appropriate for most uncomplicated cases 1, 2
• Base choice on local resistance patterns 1

Adjusting Therapy

• Modify antibiotics based on culture sensitivities within 48-72 hours 1
• If no clinical improvement by 48-72 hours, reassess diagnosis and consider imaging for complications 1
• Follow-up in 1-2 days to ensure clinical response 1

Imaging Recommendations

• Obtain renal and bladder ultrasound (RBUS) after confirming UTI to detect anatomic abnormalities 1
• VCUG indicated after second febrile UTI or if RBUS shows abnormalities 1, 2
• Risk of grade IV-V VUR is 18% after second UTI 1

Common Pitfalls to Avoid

• Never treat based on bagged urine culture alone—high contamination rate leads to overdiagnosis 1, 2
• Avoid treating asymptomatic bacteriuria—may increase resistance and future UTI risk 1
• Know your local resistance patterns—TMP-SMX and cephalexin resistance varies substantially by geography 1, 8
• Do not use fluoroquinolones as first-line in children unless no alternatives exist 1
• Multidrug resistance in E. coli can exceed 60% in some regions 8