Treatment of UTI in an 11-Year-Old
For an uncomplicated UTI in an 11-year-old child, treat with oral antibiotics for 7-14 days using first-line agents: trimethoprim-sulfamethoxazole (6-12 mg/kg trimethoprim per day in 2 divided doses), a cephalosporin (such as cefixime 8 mg/kg daily), or amoxicillin-clavulanate (20-40 mg/kg per day in 3 doses), based on local resistance patterns. 1
Initial Assessment and Route of Administration
- Most children can be treated with oral antibiotics and do not require hospitalization 1
- Parenteral (IV) therapy is only needed if the child appears toxic, cannot retain oral fluids/medications, or if compliance with oral therapy is uncertain 1
- For children requiring IV treatment initially, switch to oral therapy once clinical improvement occurs (typically within 24-48 hours) and complete the full 7-14 day course 1
First-Line Oral Antibiotic Options
The choice should be guided by local antimicrobial susceptibility patterns, as there is substantial geographic variability in resistance 1:
Trimethoprim-sulfamethoxazole:
- Dosing: 6-12 mg/kg trimethoprim and 30-60 mg/kg sulfamethoxazole per day in 2 divided doses 1
- FDA-approved for UTI treatment 2
- Check local resistance rates before using as first-line 1
Cephalosporins (multiple options):
- Cefixime: 8 mg/kg per day in 1 dose 1, 3
- Cefpodoxime: 10 mg/kg per day in 2 doses 1
- Cefprozil: 30 mg/kg per day in 2 doses 1
- Cephalexin: 50-100 mg/kg per day in 4 doses 1
Amoxicillin-clavulanate:
- Dosing: 20-40 mg/kg per day in 3 doses 1
Duration of Treatment
- Total treatment duration should be 7-14 days regardless of whether started orally or parenterally 1
- Courses shorter than 7 days (1-3 days) are inferior and should not be used for febrile UTIs 1
- The minimum duration is 7 days 1
Critical Pitfalls to Avoid
Do NOT use nitrofurantoin for febrile UTIs in children: While nitrofurantoin is appropriate for simple cystitis in adults, it should not be used in febrile children because it does not achieve adequate blood and tissue concentrations to treat pyelonephritis or urosepsis 1. It is only excreted in urine and lacks systemic distribution 1.
Parenteral Options (If Needed)
If the child requires IV therapy initially 1:
- Ceftriaxone: 75 mg/kg every 24 hours 1
- Cefotaxime: 150 mg/kg per day divided every 6-8 hours 1
- Gentamicin: 7.5 mg/kg per day divided every 8 hours 1
Follow-Up Imaging
- Renal and bladder ultrasonography (RBUS) is recommended to detect anatomic abnormalities requiring further evaluation 1
- Timing depends on clinical situation; perform within first 2 days if concerned about complications like abscess or obstruction 1
Key Considerations
- Always obtain urine culture before starting antibiotics to guide therapy adjustment based on susceptibility results 1
- The choice between oral agents should prioritize local antibiogram data over general recommendations 1
- Oral and parenteral routes are equally efficacious when the child can tolerate oral intake 1
- Geographic resistance patterns vary significantly, particularly for trimethoprim-sulfamethoxazole and cephalexin 1