What is the recommended dose of itraconazole (antifungal medication) for children?

Itraconazole Dosing in Children

The recommended dose of itraconazole for children is 5 mg/kg/day given in two divided doses (2.5 mg/kg twice daily) for most indications, with treatment doses increased to 10 mg/kg/day in two divided doses for systemic fungal infections. 1

Age-Specific Dosing Considerations

Children ≥2 years of age:

• Prophylaxis: 2.5 mg/kg twice daily (5 mg/kg/day) 1
• Treatment of oropharyngeal candidiasis: 2.5 mg/kg twice daily 1
• Treatment of esophageal candidiasis: 2.5 mg/kg twice daily (5 mg/kg/day), with loading dose of 5 mg/kg twice daily (10 mg/kg/day) on day 1 1
• Treatment of systemic fungal infections: 5 mg/kg twice daily (10 mg/kg/day) 2
• Treatment of superficial fungal infections: 5 mg/kg/day for shorter duration 2

Children <2 years of age:

• May require higher doses due to faster clearance
• Recent research shows children ≤12 years often need median doses of 6.2 mg/kg/day to achieve therapeutic levels 3
• 71.4% of children ≤12 years required doses above the recommended 5 mg/kg/day to reach therapeutic levels 3

Formulation Considerations

• Oral solution (cyclodextrin) is preferred for children and should NOT be used interchangeably with capsules 1
• Capsules are generally ineffective for treating esophageal disease 1
• For infants, the oral solution at 5 mg/kg/day provides potentially therapeutic concentrations 4

Therapeutic Drug Monitoring (TDM)

• TDM is strongly recommended for all children receiving itraconazole 1, 3
• Target trough concentration: ≥0.5 mg/L 1
• Samples should be taken at steady state (typically after 5-7 days of therapy) 3
• Children aged 6 months to 2 years tend to have more frequent low trough concentrations 4

Special Considerations

• Drug interactions: Use caution when combining with vincristine or other chemotherapeutic agents due to potential for increased toxicity 5
• Hepatotoxicity: Monitor liver function tests during therapy 3, 5
• Absorption: Administration with food improves bioavailability
• Duration of therapy:
  • Superficial fungal infections: 1-8 weeks depending on infection site 6
  • Systemic fungal infections: Based on clinical response and resolution of infection

Common Pitfalls to Avoid

1. Underdosing in younger children: Children ≤12 years often require higher doses than currently recommended to achieve therapeutic levels 3
2. Failure to perform TDM: Only 28.6% of courses with subtherapeutic levels had appropriate dose adjustments 3
3. Inappropriate formulation selection: Itraconazole cyclodextrin oral solution should not be used interchangeably with capsules 1
4. Overlooking drug interactions: Particularly with chemotherapeutic agents like vincristine 5
5. Inadequate monitoring: Regular monitoring of liver function is necessary during therapy 3

In conclusion, while the standard recommended dose is 5 mg/kg/day in divided doses, clinicians should be prepared to adjust dosing based on therapeutic drug monitoring, particularly in younger children who often require higher doses to achieve therapeutic levels.