What is the recommended dose of amoxicillin (250mg/5ml) for a pediatric patient?

Amoxicillin Dosing for Pediatric Patients (250mg/5mL Suspension)

Standard Dosing Algorithm

For most common pediatric infections, administer amoxicillin 45 mg/kg/day divided into 2 doses (every 12 hours) for mild to moderate infections, or 90 mg/kg/day divided into 2 doses for severe infections or areas with high pneumococcal resistance. 1, 2

Indication-Specific Dosing

Mild to Moderate Respiratory Tract Infections (Community-Acquired Pneumonia):

• Standard dose: 45 mg/kg/day divided every 12 hours 1, 2
• Practical calculation: For a child weighing 20 kg, this equals 450 mg per dose (9 mL of 250mg/5mL suspension) twice daily 1
• Treatment duration: 7-10 days, with clinical reassessment at 48-72 hours 1, 2

Severe Respiratory Infections or High-Resistance Areas:

• High dose: 90 mg/kg/day divided every 12 hours 1, 2, 3
• Indications for high-dose therapy: Children <2 years old, recent antibiotic exposure within 30 days, daycare attendance, or areas with >10% penicillin-resistant S. pneumoniae 1
• Practical calculation: For a 20 kg child, this equals 900 mg per dose (18 mL of 250mg/5mL suspension) twice daily 1
• Maximum daily dose: Do not exceed 4000 mg/day regardless of weight 1, 4

Group A Streptococcal Infections (Pharyngitis, Scarlet Fever):

• Dose: 50-75 mg/kg/day divided into 2 doses 1, 2
• Duration: Minimum 10 days to prevent acute rheumatic fever 1, 4
• Practical calculation: For a 20 kg child, this equals 500-750 mg per dose (10-15 mL) twice daily 1

Acute Otitis Media:

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

Age-Specific Considerations

Infants <3 Months (12 weeks):

• Maximum dose: 30 mg/kg/day divided every 12 hours due to immature renal function 4
• Duration: Minimum 48-72 hours beyond symptom resolution 4

Children ≥3 Months and <40 kg:

• Use weight-based dosing as outlined above 1, 4
• Twice-daily dosing (every 12 hours) is preferred over three-times-daily for improved compliance 1, 2

Children ≥40 kg and Adolescents:

• Transition to adult dosing: 500 mg every 12 hours for mild/moderate infections or 875 mg every 12 hours for severe infections 4
• For community-acquired pneumonia in adolescents: 2000 mg twice daily (maximum 4000 mg/day) 3

Critical Dosing Considerations

Administration Instructions:

• Give at the start of meals to minimize gastrointestinal intolerance 4
• Shake suspension well before each use 4
• Refrigeration is preferable but not required; discard unused suspension after 14 days 4

Monitoring and Follow-Up:

• Children should demonstrate clinical improvement within 48-72 hours 1, 2
• If no improvement occurs, reevaluate for resistant organisms, alternative diagnoses, or consider adding coverage for atypical pathogens 1, 3
• Complete the full course even if symptoms improve before completion 1, 2

Common Pitfalls to Avoid

Underdosing in Heavier Children:

• Primary care physicians frequently prescribe lower-than-recommended doses in older, heavier children 5
• Always calculate based on actual weight, not age, up to the maximum daily dose of 4000 mg 1, 4

Inadequate Coverage for Resistant Organisms:

• The standard 40 mg/kg/day dosing is inadequate for penicillin-resistant S. pneumoniae, particularly during viral coinfection 6
• Use 90 mg/kg/day for severe infections or high-resistance areas 1, 2, 3

Incorrect Dosing Frequency:

• Twice-daily dosing at appropriate total daily doses provides equivalent or superior outcomes compared to three-times-daily dosing and improves adherence 1, 7

Alternative Regimens

For β-Lactamase-Producing Organisms:

• Switch to amoxicillin-clavulanate 90 mg/kg/day (amoxicillin component) divided into 2 doses 1, 2

For Penicillin Allergy:

• Non-anaphylactic reactions: Use second- or third-generation cephalosporins (cefdinir, cefuroxime) 1, 3
• Type I hypersensitivity: Use azithromycin or clarithromycin, though these have inferior bacteriologic efficacy 1, 3