Metronidazole Dosing for 15.8 kg Pediatric Patient
For a child weighing 15.8 kg, administer metronidazole at 20-30 mg/kg/day divided into appropriate doses based on the specific infection being treated.
Standard Pediatric Dosing
For children under 12 years of age, the recommended dose is 20-30 mg/kg body weight per day 1. This translates to:
- Minimum daily dose: 316 mg/day (20 mg/kg × 15.8 kg)
- Maximum daily dose: 474 mg/day (30 mg/kg × 15.8 kg)
Practical Dosing Regimens
For Most Anaerobic Infections
- Divided dosing: 158-237 mg given twice daily (every 12 hours)
- Alternative: 105-158 mg given three times daily (every 8 hours)
The drug demonstrates excellent tissue penetration including the central nervous system and is bactericidal against almost all obligately anaerobic organisms 2. Metronidazole has oral bioavailability approaching 100%, making oral administration as effective as intravenous 3.
Age-Related Pharmacokinetic Considerations
Important caveat: Children older than 4 years have pharmacokinetic parameters similar to adults, but younger children may have prolonged elimination half-lives and reduced total body clearance 3. For a child weighing 15.8 kg (likely 3-5 years old based on typical growth patterns), standard weight-based dosing is appropriate without adjustment.
Infection-Specific Guidance
The dosing remains consistent at 20-30 mg/kg/day regardless of whether treating:
Duration of Therapy
Treatment duration varies by indication but typically ranges from 5-10 days for most anaerobic infections 4. The drug should only be used for approved indications given its mutagenic potential in animal studies, though follow-up studies in humans have not revealed increased cancer incidence 2.
Administration Recommendations
- Oral administration preferred: Given near-complete bioavailability 3
- Timing: Can be given with food to minimize gastrointestinal side effects
- Avoid alcohol: Disulfiram-like reaction can occur 2
Monitoring Considerations
Watch for reversible neutropenia and peripheral neuropathy, though these are uncommon at standard therapeutic doses 2. The drug has limited plasma protein binding but achieves favorable tissue distribution 3.