What is the recommended dose of amoxicillin (amoxicillin) for a 10-year-old child?

Amoxicillin Dosing for a 10-Year-Old Child

For a 10-year-old child, amoxicillin dosing is weight-based rather than age-based, with standard dosing of 45 mg/kg/day divided into 2 doses for mild to moderate infections, or 90 mg/kg/day divided into 2 doses for severe infections or high-resistance areas, not exceeding a maximum of 4000 mg/day. 1

Weight-Based Dosing Algorithm

The appropriate dose depends on the child's weight and the specific infection being treated:

Standard Dosing for Common Infections

• For mild to moderate respiratory tract infections (including community-acquired pneumonia), prescribe 45 mg/kg/day divided every 12 hours 1, 2
• For severe infections or areas with high pneumococcal resistance (>10% penicillin-resistant S. pneumoniae), prescribe 90 mg/kg/day divided every 12 hours 1, 2
• For Group A Streptococcal pharyngitis, prescribe 50-75 mg/kg/day divided into 2 doses for 10 days, not exceeding 1000 mg per dose 1

Practical Example Calculations

Assuming a typical 10-year-old weighs approximately 30-35 kg:

• Standard dose (45 mg/kg/day): 675-788 mg twice daily (approximately 700-800 mg every 12 hours) 1
• High dose (90 mg/kg/day): 1350-1575 mg twice daily (approximately 1400-1500 mg every 12 hours) 1, 2

Critical Dosing Considerations

• Maximum daily dose: Never exceed 4000 mg/day regardless of weight 1
• Dosing frequency: Twice-daily dosing (every 12 hours) is preferred over three-times-daily dosing because it improves adherence and achieves superior pharmacokinetic profiles 2
• Administration timing: Amoxicillin should be taken at the start of a meal to minimize gastrointestinal intolerance 3

Indication-Specific Guidance

Community-Acquired Pneumonia

• Mild to moderate: 45 mg/kg/day in 2 doses 1, 2
• Severe or high-resistance areas: 90 mg/kg/day in 2 doses 1, 2
• Treatment duration: 5-7 days for outpatient pneumonia, with reassessment if symptoms persist beyond 48-72 hours 2

Acute Bacterial Sinusitis

• Children ≥2 years without risk factors: 45 mg/kg/day divided every 12 hours 1
• Children <2 years, in daycare, or with recent antibiotic use: 80-90 mg/kg/day divided every 12 hours 1

Streptococcal Pharyngitis

• Standard dose: 50-75 mg/kg/day in 2 doses for 10 days 1
• Important: Complete the full 10-day course to prevent acute rheumatic fever 3

Common Pitfalls and How to Avoid Them

• Age-based dosing error: Always calculate based on weight, not age, as a 10-year-old's weight can vary significantly (typically 25-45 kg) 1
• Underdosing in high-resistance areas: If the child attends daycare, has received antibiotics in the past 30 days, or lives in an area with >10% penicillin-resistant S. pneumoniae, use the high-dose regimen (90 mg/kg/day) 1
• Inadequate treatment duration: Ensure at least 48-72 hours of treatment beyond symptom resolution 3
• Prescription clarity: The prescription should specify the daily dose, number of divided doses, duration of therapy, indication, and the child's weight 4

When to Use Amoxicillin-Clavulanate Instead

• For β-lactamase-producing organisms (H. influenzae, M. catarrhalis): Switch to amoxicillin-clavulanate at 90 mg/kg/day of the amoxicillin component 1
• Recent antibiotic exposure (within 4-6 weeks): Consider high-dose amoxicillin-clavulanate (90 mg/6.4 mg per kg per day of the amoxicillin component) 1

Monitoring and Follow-Up

• Expected improvement: Children on appropriate therapy should demonstrate clinical improvement within 48-72 hours 1, 2
• Fever resolution: Fever typically resolves within 24-48 hours for pneumococcal infections, though cough may persist longer 1
• Reevaluation criteria: If no improvement occurs within 48-72 hours, reevaluation and further investigation are necessary 1, 2