What is the recommended dose of vancomycin for a 9-year-old boy with normal renal function?

Vancomycin Dosing for a 9-Year-Old Boy

For a 9-year-old boy with normal renal function, administer vancomycin 60 mg/kg/day divided into doses given every 6 hours (15 mg/kg per dose every 6 hours). 1, 2

Standard Pediatric Dosing Algorithm

Initial Dosing Strategy

• Start with 60 mg/kg/day divided every 6 hours for children with normal renal function, as this dosing achieves therapeutic peak and trough concentrations more reliably than the traditional 40 mg/kg/day regimen 1, 3

• The older guideline recommendation of 40 mg/kg/day divided every 6-8 hours 1 frequently results in subtherapeutic levels in pediatric intensive care patients, requiring dose escalation 3

• For a typical 9-year-old weighing approximately 30 kg, this translates to 450 mg every 6 hours (1,800 mg total daily dose) 1, 3

Dosing Based on Infection Severity

For less severe infections:

• 40-60 mg/kg/day divided every 6-8 hours is acceptable 1, 2
• Target trough concentrations of 10-15 μg/mL 2, 4

For serious or invasive infections (bacteremia, endocarditis, meningitis, osteomyelitis, pneumonia):

• Use the higher end: 60 mg/kg/day or 15 mg/kg per dose every 6 hours 1, 3
• Target trough concentrations of 15-20 μg/mL 2, 4
• Consider a loading dose of 15 mg/kg for rapid achievement of therapeutic levels 5

Critical Monitoring Requirements

• Obtain trough concentrations before the fourth dose to assess adequacy and guide adjustments 2, 6
• Monitor renal function closely throughout therapy, as vancomycin requires dose adjustment with any decline in kidney function 1, 2
• Trough concentrations >5 μg/mL are highly predictive of corresponding peak concentrations >20 μg/mL, potentially eliminating the need for routine peak monitoring 3

Administration Considerations

• Infuse each dose over at least 1 hour to minimize the risk of red man syndrome (histamine-release reaction) 5, 4
• For doses exceeding 500 mg, extend infusion time to 1.5-2 hours 4

Common Pitfalls to Avoid

• Do not use fixed adult doses (such as 1 gram every 12 hours) in pediatric patients, as weight-based dosing is essential 1, 4
• Do not underdose with 40 mg/kg/day for serious infections, as pediatric patients—particularly those in intensive care settings—require higher doses (60 mg/kg/day) to achieve therapeutic concentrations 3
• Do not delay therapeutic drug monitoring—obtain the first trough before the fourth dose to ensure adequate exposure early in therapy 2, 6
• Do not ignore augmented renal clearance in critically ill children, which may require doses up to 75 mg/kg/day to achieve target AUC/MIC ratios 7

Special Populations

For children with augmented renal clearance:

• Increase dosing to 75 mg/kg/day for children aged 1 month to 12 years 7
• Standard dosing of 60 mg/kg/day carries high risk of underdosing in this population 7

For neonates and infants:

• Use 40 mg/kg/day divided every 6-8 hours as the starting point 2
• Adjust based on therapeutic drug monitoring 2