Pediatric Dosing of Metronidazole
The recommended dose of metronidazole for pediatric patients is 30-40 mg/kg/day divided every 8 hours, with a maximum of 500 mg per dose. 1
General Dosing Guidelines
- For most infections requiring metronidazole in children, the standard dose is 30-40 mg/kg/day divided into three doses (every 8 hours) 1, 2
- The maximum dose per administration is 500 mg 2
- The standard duration of therapy for most infections is 10 days 2
- For intra-abdominal infections, metronidazole can be used as part of a combination antimicrobial regimen 1
Dosing by Specific Condition
Intra-abdominal Infections
- Metronidazole at 30-40 mg/kg/day divided every 8 hours is recommended as part of combination therapy 1
- Can be combined with aminoglycosides, carbapenems, or advanced-generation cephalosporins for complicated intra-abdominal infections 1
Clostridium difficile Infection
- For non-severe infections: 7.5 mg/kg/dose three or four times daily (maximum 500 mg per dose) for 10 days 2
- For severe infections requiring IV therapy: 10 mg/kg/dose three times daily (maximum 500 mg per dose) 2
Crohn's Disease with Perianal Fistulizing Disease
- For perianal disease: 10-20 mg/kg/day divided doses 1
- Used as adjuvant therapy in more severe perianal fistulizing disease 1
Alternative Dosing Approaches
- Recent pharmacokinetic/pharmacodynamic studies suggest that once-daily dosing of metronidazole at 30 mg/kg/dose may be effective for appendicitis, achieving target concentrations for Bacteroides fragilis with MICs ≤2 mcg/mL 3
- This approach achieved similar area under the curve (AUC) values to adults receiving 1000-1500 mg once daily or 500 mg every 8 hours 3
Considerations for Specific Infections
- For giardiasis: 15 mg/kg/day in three divided doses for 7 days has shown 90% efficacy 4
- For anaerobic infections: Intravenous dosing at 30 mg/kg/day or oral dosing at 40-50 mg/kg/day has demonstrated good efficacy and safety 5
Important Caveats
- Metronidazole dosing should be adjusted based on the severity of infection 2
- Side effects may include nausea, anorexia, and metallic taste 4
- For severe infections, higher doses within the recommended range may be warranted 1, 2
- When treating complicated intra-abdominal infections, metronidazole should be used as part of a broader antimicrobial regimen 1