What is the recommended dose of amoxicillin (Amoxil) for a 1-year-old child weighing 7.7 kg?

Amoxicillin Dosing for a 1-Year-Old Weighing 7.7 kg

For a 1-year-old child weighing 7.7 kg, the recommended dose of amoxicillin is 45 mg/kg/day divided into two doses (every 12 hours) for mild to moderate infections, which equals approximately 173 mg twice daily or 1.7 mL of 250 mg/5 mL suspension twice daily. 1

Standard Dosing Algorithm

Mild to Moderate Infections

• The American Academy of Pediatrics recommends 45 mg/kg/day divided every 12 hours for uncomplicated respiratory tract infections, skin infections, and genitourinary infections in children ≥3 months old and weighing <40 kg. 1
• For this 7.7 kg child: 45 mg/kg/day × 7.7 kg = 346.5 mg total daily dose, administered as 173 mg twice daily (every 12 hours). 1
• Using 250 mg/5 mL suspension: 1.7 mL twice daily. 2

Severe Infections or High-Resistance Areas

• For severe infections or areas with high pneumococcal resistance (>10%), the Infectious Diseases Society of America recommends 90 mg/kg/day divided every 12 hours. 1
• This applies to children with: 1
  • Age <2 years
  • Recent antibiotic exposure within 30 days
  • Daycare attendance
  • Severe illness requiring hospitalization
• For this 7.7 kg child: 90 mg/kg/day × 7.7 kg = 693 mg total daily dose, administered as 347 mg twice daily. 1
• Using 250 mg/5 mL suspension: 3.5 mL twice daily. 2

Indication-Specific Considerations

Community-Acquired Pneumonia

• For mild to moderate pneumonia, use 45 mg/kg/day in 2 doses (173 mg twice daily for this child). 1
• For severe pneumonia or high pneumococcal resistance areas, use 90 mg/kg/day in 2 doses (347 mg twice daily for this child). 1

Group A Streptococcal Infections

• The American Heart Association recommends 50-75 mg/kg/day in 2 doses for 10 days, not exceeding 1000 mg per dose. 1
• For this 7.7 kg child: 385-578 mg daily, divided as 193-289 mg twice daily. 1

Treatment Duration and Monitoring

• The standard treatment duration for most respiratory infections is 7-10 days, with pneumonia specifically requiring 10 days. 1, 3
• Children on appropriate therapy should demonstrate clinical improvement within 48-72 hours. 1, 3
• If no improvement occurs within 48-72 hours, reevaluation and further investigation are necessary. 1, 3

Administration Guidelines

• Amoxicillin should be taken at the start of a meal to minimize gastrointestinal intolerance. 2
• After reconstitution, shake the oral suspension well before each use. 2
• Any unused portion of reconstituted suspension must be discarded after 14 days; refrigeration is preferable but not required. 2

Critical Dosing Considerations

• The maximum daily dose of amoxicillin should not exceed 4000 mg/day regardless of weight. 1
• For pediatric patients aged less than 12 weeks (3 months), the recommended upper dose is 30 mg/kg/day divided every 12 hours due to incompletely developed renal function. 2

Common Pitfalls to Avoid

• Do not use subtherapeutic doses, as they fail to achieve adequate concentrations and promote antimicrobial resistance. 4
• Verify the suspension concentration (125 mg/5 mL vs 250 mg/5 mL) before calculating volume to avoid dosing errors. 4
• For β-lactamase-producing organisms (H. influenzae, M. catarrhalis), use amoxicillin-clavulanate instead of amoxicillin alone at 90 mg/kg/day of the amoxicillin component. 1