What is the recommended treatment for a pediatric patient with a urinary tract infection (UTI)?

Treatment of Pediatric Urinary Tract Infections

Treat most pediatric UTIs with oral antibiotics for 7-14 days, reserving parenteral therapy only for toxic-appearing children, those unable to retain oral medications, or infants under 28 days of age. 1

Initial Antibiotic Selection by Age and Clinical Presentation

Neonates (<28 days)

• Hospitalize all neonates and administer parenteral therapy with ampicillin plus either an aminoglycoside or third-generation cephalosporin for a total of 14 days 1, 2
• These infants require supportive care and close monitoring due to higher risk of complications 3

Infants 29 days to 2 months

• Use ceftriaxone 50 mg/kg IV/IM every 24 hours as standard empiric therapy for confirmed or suspected febrile UTI 1
• For stable, well-appearing infants who can tolerate oral medications, oral cephalexin (50-100 mg/kg/day in 4 divided doses) or cefixime (8 mg/kg/day once daily) are acceptable alternatives 1
• Continue until afebrile for 24 hours, then complete 14 days total with oral antibiotics 3

Children >2 months with febrile UTI (pyelonephritis)

First-line oral options include: 1, 4

• Amoxicillin-clavulanate
• Cephalosporins (cefixime, cefpodoxime, cefprozil, cefuroxime, cephalexin)
• Trimethoprim-sulfamethoxazole (only if local E. coli resistance <10%) 1

Parenteral option when needed:

• Ceftriaxone 50 mg/kg IV/IM every 24 hours until clinically improved and afebrile for 24 hours, then transition to oral therapy 1

Children with non-febrile UTI (cystitis)

First-line oral options include: 1, 5

• Cephalexin (covers 85% of lower UTI pathogens)
• Nitrofurantoin (covers 80% of lower UTI pathogens, but never use for febrile UTI/pyelonephritis as it doesn't achieve adequate tissue concentrations) 1, 4
• Cefixime (covers 82% of lower UTI pathogens)
• Trimethoprim-sulfamethoxazole (if local resistance <20% for lower UTI) 1

Treatment Duration

For febrile UTI/pyelonephritis: 7-14 days total, with 10 days being most commonly recommended 1, 4, 6

• Shorter courses (1-3 days) are definitively inferior and should never be used 1, 4
• Some evidence suggests 5-9 days may be adequate for children >2 years, but this is not conclusive 1

For non-febrile UTI/cystitis: 7-10 days for moderate-to-severe symptoms 1, 6

• Shorter courses (3-5 days) may be comparable to longer courses for uncomplicated cystitis 1

Critical Timing Considerations

Start antibiotics within 48 hours of fever onset to reduce renal scarring risk by more than 50% 1, 6

• Early treatment is one of the most important modifiable factors affecting long-term outcomes 1

When to Use Parenteral Therapy

Indications for IV/IM antibiotics: 1, 4

• Toxic or septic appearance
• Unable to retain oral intake or medications
• Age <28 days (always)
• Uncertain compliance with oral therapy
• Failure to improve within 48 hours on oral therapy

Adjusting Therapy Based on Culture Results

Always obtain urine culture before starting antibiotics via catheterization or suprapubic aspiration in non-toilet-trained children, or clean-catch midstream in toilet-trained children 1, 7

• Bag specimens should never be used for culture due to 85% false-positive rate 1

Adjust antibiotics based on culture and sensitivity results when available, considering local resistance patterns 1, 4

• E. coli resistance to trimethoprim-sulfamethoxazole ranges from 19-63% in some regions 4
• Extended-spectrum beta-lactamase (ESBL) producing E. coli remains stable at 7-10% in pediatrics 2

Imaging Recommendations

Renal and bladder ultrasound (RBUS):

• Obtain for all children <2 years with first febrile UTI to detect anatomic abnormalities 1, 4
• Not routinely needed for children >2 years with first uncomplicated febrile UTI that responds well to treatment 1, 4
• Never needed for non-febrile UTI/cystitis regardless of age 1

Voiding cystourethrography (VCUG):

• Not recommended routinely after first UTI 1, 4
• Perform after second febrile UTI 1, 4
• Consider if RBUS shows hydronephrosis, scarring, or findings suggesting high-grade vesicoureteral reflux or obstruction 1
• Consider if fever persists >48 hours on appropriate therapy 1

Follow-Up Strategy

Short-term (1-2 days):

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

Long-term:

• No routine scheduled visits after successful treatment of first uncomplicated UTI 1
• Instruct parents to seek prompt evaluation (within 48 hours) for any future febrile illness to detect recurrent UTIs early 1

Antibiotic Prophylaxis

Continuous antibiotic prophylaxis is NOT routinely recommended for: 1, 8

• Children after first UTI
• Children with recurrent UTIs
• Children with vesicoureteral reflux grades I-IV
• Children with isolated hydronephrosis
• Children with neurogenic bladder

Consider prophylaxis only for:

• Significant obstructive uropathies until surgical correction 1
• High-risk patients with recurrent febrile UTIs where benefits outweigh antimicrobial resistance risks 1

The RIVUR trial showed prophylaxis reduced recurrent UTI by 50% but did not reduce renal scarring 1, and prophylaxis increases antimicrobial resistance risk 8

Critical Pitfalls to Avoid

Never use nitrofurantoin for febrile UTI/pyelonephritis as it doesn't achieve adequate serum/parenchymal concentrations 1, 4

Never treat for less than 7 days for febrile UTI as shorter courses are proven inferior 1, 4

Never use bag specimens for urine culture due to unacceptably high false-positive rates 1

Never delay obtaining urine culture before starting antibiotics as this is your only opportunity for definitive diagnosis and antibiotic adjustment 1, 7

Never order imaging for non-febrile first UTI as it is not indicated and increases unnecessary costs and radiation exposure 1

Never treat asymptomatic bacteriuria as this may be harmful and lead to resistant organisms 4

Avoid fluoroquinolones in children due to musculoskeletal safety concerns; reserve only for severe infections where benefits outweigh risks 1

When to Refer to Pediatric Nephrology/Urology

Refer for: 1

• Recurrent febrile UTIs (≥2 episodes)
• Abnormal renal ultrasound showing hydronephrosis, scarring, or structural abnormalities
• Poor response to appropriate antibiotics within 48 hours
• Non-E. coli organisms or suspected complicated infection