What is the treatment for pyelonephritis in children?

Treatment of Pyelonephritis in Children

For children older than 6 months with uncomplicated pyelonephritis, oral third-generation cephalosporins (such as cefixime or co-amoxiclav) are as effective as initial IV therapy and should be the first-line treatment, with a total duration of 7-10 days. 1, 2, 3

Age-Specific Treatment Algorithms

Neonates and Infants <6 Months

• Hospitalize all neonates and young infants with suspected pyelonephritis due to high risk of bacteremia (4-36% incidence) and nonspecific presentation 4
• Initiate parenteral ampicillin PLUS gentamicin as first-line therapy, with gentamicin dosing adjusted for gestational and postnatal age 1, 5
• Alternative regimen: ampicillin plus cefotaxime for neonates <28 days 5
• Continue parenteral therapy for 3-4 days until afebrile for 24 hours, then transition to oral antibiotics to complete 14 days total duration 5

Infants 6 Months to Children >6 Months (Uncomplicated)

• Third-generation cephalosporin monotherapy is the recommended first-line treatment 1
• Oral therapy alone (cefixime 14 days or co-amoxiclav 10 days) is equally effective as IV-then-oral regimens for preventing renal scarring (13.7% vs 17.7%, no significant difference) 2, 3
• If IV therapy is chosen initially, use ceftriaxone 50-75 mg/kg/day once daily for 3-4 days, then switch to oral therapy to complete 7-10 days total 1, 2, 6
• Single daily dosing of aminoglycosides (gentamicin) is safe and effective if IV therapy is selected 2, 5

Complicated Pyelonephritis (All Ages)

• Hospitalize and initiate ceftazidime PLUS ampicillin OR aminoglycoside PLUS ampicillin for broader coverage 1
• Continue parenteral therapy until clinically improved and afebrile for 24 hours, then complete 10-14 days with oral antibiotics 5

Alternative Oral Agents (When Susceptibility Known)

Trimethoprim-Sulfamethoxazole

• Only use when pathogen susceptibility is confirmed due to high resistance rates 4, 1
• Dosing: 40 mg/kg sulfamethoxazole + 8 mg/kg trimethoprim per 24 hours divided every 12 hours for 10-14 days in children >2 months 7, 8
• Not recommended for empiric therapy without culture results 1, 9

Oral Cephalosporins

• Ceftibuten switch therapy after defervescence is effective and reduces hospitalization duration 6
• Co-amoxiclav (50 mg/kg/day divided three times daily for 10 days) shows equivalent efficacy to IV ceftriaxone 3, 10

Critical Caveats and Pitfalls

Antibiotics to AVOID in Pediatric Pyelonephritis

• Fluoroquinolones should be avoided in children unless no alternatives exist due to cartilage toxicity concerns 1
• Nitrofurantoin is contraindicated for pyelonephritis—only indicated for cystitis, not upper tract infections 1, 9
• Oral fosfomycin should not be used due to insufficient efficacy data for upper tract disease 1, 9

Local Resistance Patterns

• If local E. coli resistance to third-generation cephalosporins exceeds 10%, consider alternative agents or initial IV dose of long-acting parenteral antibiotic 1
• Always obtain urine culture before initiating antibiotics to guide therapy adjustment 1

Duration Considerations

• Shorter courses (7-10 days) are sufficient with comparable clinical success to traditional 14-day regimens 1, 2, 3
• For beta-lactams specifically, 7 days is adequate; for fluoroquinolones (if used), 5-7 days 1

Monitoring and Follow-Up

• Obtain urine culture and susceptibility testing before starting antibiotics in all cases 1
• Expect clinical improvement and defervescence within 24-48 hours; if fever persists beyond 72 hours, consider imaging for complications 9
• Consider renal ultrasound or DMSA scan after first febrile UTI to assess for complications or renal scarring, particularly in high-risk patients 4, 1
• Renal scarring occurs in approximately 15% of children after first pyelonephritis episode, with risk not decreasing in older children 4