For a 2‑year‑old child weighing approximately 12 kg, is the appropriate amoxicillin formulation the 400 mg per 5 mL suspension?

Amoxicillin 400mg/5mL Suspension for a 2-Year-Old Child

Yes, the 400 mg/5 mL formulation is NOT a standard concentration available for amoxicillin suspension. The FDA-approved formulations are 125 mg/5 mL and 250 mg/5 mL 1.

Standard Available Formulations

For a 2-year-old child weighing approximately 12 kg, you should use one of these FDA-approved concentrations 1:

• 125 mg/5 mL suspension
• 250 mg/5 mL suspension

Appropriate Dosing for This Child

For Community-Acquired Pneumonia (CAP)

High-dose amoxicillin is recommended at 90 mg/kg/day divided into 2 doses 2. For a 12 kg child:

• Total daily dose: 1,080 mg/day
• Per dose: 540 mg twice daily

Using the 250 mg/5 mL formulation, you would prescribe:

• 10.8 mL (approximately 11 mL) twice daily 1

For Acute Otitis Media (AOM)

High-dose amoxicillin at 80-90 mg/kg/day in 2 doses is preferred 2. For a 12 kg child:

• Total daily dose: 960-1,080 mg/day
• Per dose: 480-540 mg twice daily

Using the 250 mg/5 mL formulation:

• 9.6-10.8 mL (approximately 10-11 mL) twice daily 1

For Mild Infections (Skin/ENT)

Standard-dose amoxicillin at 45 mg/kg/day in 2 doses 1. For a 12 kg child:

• Total daily dose: 540 mg/day
• Per dose: 270 mg twice daily

Using the 125 mg/5 mL formulation:

• 10.8 mL (approximately 11 mL) twice daily 1

Key Clinical Considerations

Concentration Selection

• Use 250 mg/5 mL for high-dose regimens to minimize volume and improve adherence 1
• Use 125 mg/5 mL for standard-dose regimens when lower concentrations are adequate 1

Common Pitfall: Weight-Based Dosing Disparity

Smaller children often receive appropriate mg/kg dosing, while larger children are frequently underdosed 3, 4. For this 12 kg child, ensure you calculate the full weight-based dose rather than defaulting to lower "standard" doses 3.

Administration Instructions

• Give at the start of meals to minimize gastrointestinal intolerance 1
• Shake suspension well before each use 1
• Use a calibrated oral syringe for accurate dosing 1
• Refrigeration is preferable but not required 1
• Discard unused suspension after 14 days 1

Duration of Therapy

• 5-10 days for most respiratory infections, with 10 days being best studied 2
• Shorter 3-day courses may be adequate for mild pneumonia, though cough resolution may take slightly longer 5
• Minimum 48-72 hours beyond symptom resolution 1