Cefixime Dosing for Pediatric UTI
The recommended dose of cefixime for urinary tract infections in children is 8 mg/kg/day, which can be administered as a single daily dose or divided into two doses of 4 mg/kg every 12 hours. 1, 2
Dosing Regimen
- Cefixime 8 mg/kg/day is the standard dose for pediatric patients 6 months of age or older with uncomplicated UTI 1, 2
- The dose may be given as a single daily dose or split into 4 mg/kg every 12 hours 2
- The maximum daily dose should not exceed 400 mg 2
Age and Weight Considerations
- Cefixime is FDA-approved for children ≥6 months of age with uncomplicated UTI 2
- For children weighing more than 45 kg or older than 12 years, use the adult dose of 400 mg daily 2
- Weight-based dosing tables are available in the FDA label to guide precise dosing for different weight ranges 2
Treatment Duration
- The total course of therapy should be 7 to 14 days 1, 3
- Shorter courses of 1-3 days have been shown to be inferior for febrile UTIs and should be avoided 1, 3
- The American Academy of Pediatrics could not identify a single preferred duration within this range, but 7 days represents the minimum acceptable duration 1
Clinical Context and Route Selection
- Cefixime is appropriate for oral treatment in children who are not toxic-appearing and can retain oral medications 1, 3
- For children who appear toxic or cannot tolerate oral intake, initial parenteral therapy (such as ceftriaxone 75 mg/kg every 24 hours or cefotaxime 150 mg/kg/day divided every 6-8 hours) should be used until clinical improvement occurs, typically within 24-48 hours 1, 3
- Once the child improves and can retain oral medications, transition to oral cefixime is appropriate 1
Important Caveats
- Cefixime should NOT be used for febrile UTIs or suspected pyelonephritis if it does not achieve adequate serum concentrations, as agents that are only excreted in urine (like nitrofurantoin) may be insufficient for parenchymal infections 1
- However, cefixime does achieve therapeutic serum levels (unlike nitrofurantoin) and is appropriate for febrile UTI when given at the recommended dose 4, 5
- Local antimicrobial resistance patterns should guide empiric therapy selection, as there is substantial geographic variability in susceptibility patterns 1, 3
- All Gram-negative organisms in pediatric studies showed susceptibility to cefixime, making it a reliable empiric choice 5
Pharmacokinetic Support
- Plasma and urine concentrations of cefixime at 8 mg/kg dosing remain above the minimal inhibitory concentration for most common urinary pathogens for up to 12 hours in plasma and 24 hours in urine 4
- Approximately 15-20% of cefixime is excreted unchanged in the urine as active drug, providing adequate urinary concentrations 6, 4
- Once-daily dosing has shown comparable efficacy to twice-daily trimethoprim-sulfamethoxazole in clinical trials 5
Formulation Considerations
- Cefixime oral suspension is available in two concentrations: 100 mg/5 mL and 200 mg/5 mL 2
- All orders specifying a dose in milliliters must include the concentration to avoid dosing errors 2
- The suspension formulation should be used rather than tablets/capsules when available, as it may result in higher peak blood levels at equivalent doses 2