What is the dose of amoxicillin (400 mg/kg/day) for a 20‑month‑old child weighing 10.6 kg?

Amoxicillin Dosing Calculation for a 20-Month-Old Child Weighing 10.6 kg

For a 20-month-old child weighing 10.6 kg requiring amoxicillin at 400 mg/kg/day, the total daily dose is 4,240 mg per day, which exceeds the maximum safe pediatric dose of 4,000 mg/day (4 g/day). 1, 2

Critical Safety Consideration

• The requested dose of 400 mg/kg/day is not a standard or safe amoxicillin dosing regimen for pediatric patients. 1, 2
• The maximum recommended daily dose of amoxicillin for children is 90 mg/kg/day with an absolute maximum of 4,000 mg/day (4 g/day), regardless of weight. 1, 2, 3

Standard Pediatric Amoxicillin Dosing Algorithm

For Mild to Moderate Infections

• The recommended dose is 45 mg/kg/day divided into 2 doses (every 12 hours). 1, 3
• For this 10.6 kg child: 45 mg/kg/day × 10.6 kg = 477 mg/day (approximately 240 mg every 12 hours). 1

For Severe Infections or High Pneumococcal Resistance Areas

• The recommended dose is 90 mg/kg/day divided into 2 doses (every 12 hours). 1, 2, 3
• For this 10.6 kg child: 90 mg/kg/day × 10.6 kg = 954 mg/day (approximately 480 mg every 12 hours). 1

Practical Dosing Using Available Formulations

Using 250 mg/5 mL Suspension

For mild to moderate infections (45 mg/kg/day):

• Give 2.4 mL every 12 hours (240 mg per dose). 1, 3

For severe infections (90 mg/kg/day):

• Give 4.8 mL every 12 hours (480 mg per dose). 1, 3

Using 400 mg/5 mL Suspension

For mild to moderate infections (45 mg/kg/day):

• Give 1.5 mL every 12 hours (240 mg per dose). 1

For severe infections (90 mg/kg/day):

• Give 3 mL every 12 hours (480 mg per dose). 1

Indication-Specific Dosing Guidance

Community-Acquired Pneumonia

• Use 90 mg/kg/day divided into 2 doses to ensure adequate coverage for penicillin-resistant Streptococcus pneumoniae. 1, 2
• For this child: 480 mg every 12 hours. 1

Group A Streptococcal Infections

• Use 50-75 mg/kg/day divided into 2 doses for 10 days. 1
• For this child: 530-795 mg/day (approximately 265-400 mg every 12 hours). 1

Acute Otitis Media (Uncomplicated)

• Use 45 mg/kg/day divided into 2 doses. 1
• For this child: 240 mg every 12 hours. 1

Common Pitfalls to Avoid

• Never exceed 4,000 mg/day total dose, regardless of calculated weight-based dosing. 1, 2
• The dose of 400 mg/kg/day appears to be an error—this is 4-8 times higher than standard pediatric dosing and would result in serious overdosing. 1, 2
• Always verify the intended indication before prescribing, as dosing varies significantly (45-90 mg/kg/day range). 1, 3
• Ensure proper reconstitution of oral suspension and shake well before each dose. 3
• Administer at the start of a meal to minimize gastrointestinal intolerance. 3

Treatment Duration

• Continue treatment for a minimum of 48-72 hours beyond symptom resolution or evidence of bacterial eradication. 3
• For Group A Streptococcal infections, treat for at least 10 days to prevent acute rheumatic fever. 3
• For pneumonia, the standard duration is 10 days. 1