Cefixime Dosing Assessment for 12 kg Pediatric Patient
Direct Answer
No, 2.5 mL BID of 100 mg/5 mL cefixime (total daily dose of 100 mg or 8.3 mg/kg/day) is significantly underdosed for a 12 kg patient and should not be used. 1
Correct Dosing
The appropriate dose for this patient is 8 mg/kg/day of cefixime suspension, which equals 96 mg daily (approximately 5 mL once daily OR 2.5 mL twice daily of the 100 mg/5 mL suspension). 1
Calculation Details
- Patient weight: 12 kg
- Recommended dose: 8 mg/kg/day 1
- Total daily dose needed: 12 kg × 8 mg/kg = 96 mg/day
- Using 100 mg/5 mL concentration: 96 mg = approximately 5 mL total daily dose 1
Dosing Options
The FDA-approved dosing allows two administration schedules 1:
- Once daily: 5 mL of 100 mg/5 mL suspension (96 mg) given as single dose
- Twice daily: 2.5 mL of 100 mg/5 mL suspension (48 mg) every 12 hours
Why the Prescribed Dose is Incorrect
The prescribed regimen of 2.5 mL BID delivers only 100 mg/day total (8.3 mg/kg/day), which appears correct at first glance. 1 However, this is the minimum recommended dose, and for a 12 kg patient, the FDA dosing table specifically recommends 100 mg/day (5 mL of 100 mg/5 mL suspension) as the appropriate dose. 1
Critical Dosing Considerations
Concentration Verification
Always verify the concentration when prescribing cefixime suspension, as it is available in two concentrations: 100 mg/5 mL and 200 mg/5 mL. 1 Prescribing errors commonly occur when the concentration is not specified.
Weight-Based Dosing Table
According to FDA guidelines for pediatric patients 10.1-12.5 kg 1:
- Recommended daily dose: 100 mg
- Using 100 mg/5 mL: 5 mL/day
- Using 200 mg/5 mL: 2.5 mL/day
Duration of Therapy
For infections caused by Streptococcus pyogenes, cefixime must be administered for at least 10 days. 1 For other indications, duration varies based on clinical response.
Clinical Evidence Supporting Dosing
Research demonstrates that cefixime at 8 mg/kg/day achieves adequate serum and urinary concentrations well above the MIC90 for indicated organisms. 2 The drug's half-life of 3-4 hours supports once or twice daily dosing. 2
In pediatric studies, cefixime at 10-20 mg/kg/day divided into two doses has shown excellent efficacy for various infections. 3, 4 The lower end of this range (8 mg/kg/day) is the FDA-approved dose for most indications. 1
Common Prescribing Pitfalls
The most frequent error is prescribing 2.5 mL BID without specifying concentration, which could result in either underdosing (if 100 mg/5 mL) or appropriate dosing (if 200 mg/5 mL). 1 Always include the concentration in the prescription.
Another common mistake is using the tablet or capsule formulation for otitis media instead of the suspension, as the suspension achieves higher peak blood levels. 1
Monitoring and Follow-Up
Ensure adequate clinical response within 48-72 hours of initiating therapy. 1 If treating Streptococcus pyogenes pharyngitis, complete the full 10-day course even if symptoms resolve earlier to prevent rheumatic fever complications. 1
Gastrointestinal adverse effects are more common with once-daily 400 mg dosing compared to divided doses. 5 For pediatric patients, the twice-daily regimen may be better tolerated.