Amoxicillin Dosing for a 14kg Child
For a 14kg child, the standard amoxicillin dose is 315mg twice daily (45 mg/kg/day divided every 12 hours) for mild to moderate infections, or 630mg twice daily (90 mg/kg/day divided every 12 hours) for severe infections or areas with high pneumococcal resistance. 1, 2
Practical Dosing Based on Available Formulations
For Mild to Moderate Infections (45 mg/kg/day):
- Total daily dose: 630mg (45 mg/kg/day × 14kg) 1, 2
- Per dose: 315mg twice daily 1, 2
- Using 250mg/5mL suspension: 6.3 mL twice daily 3
- Using 125mg/5mL suspension: 12.6 mL twice daily 3
For Severe Infections or High Resistance Areas (90 mg/kg/day):
- Total daily dose: 1260mg (90 mg/kg/day × 14kg) 1, 2
- Per dose: 630mg twice daily 1, 2
- Using 250mg/5mL suspension: 12.6 mL twice daily 3
- Maximum daily dose is 4000mg, so this child is well within safe limits 1, 2, 3
Indication-Specific Recommendations
Respiratory Tract Infections (Pneumonia, Bronchitis):
- Standard dose: 45 mg/kg/day (315mg twice daily) for mild to moderate infections 1, 2
- High dose: 90 mg/kg/day (630mg twice daily) for severe infections or high pneumococcal resistance areas 1, 2
- Duration: 10 days for pneumonia; 7-10 days for other respiratory infections 1, 2
Group A Streptococcal Infections (Strep Throat, Scarlet Fever):
- Dose: 50-75 mg/kg/day divided into 2 doses 1, 2
- For 14kg child: 350-525mg twice daily (7-10.5 mL of 250mg/5mL suspension twice daily) 1, 2
- Maximum per dose: 1000mg 1, 2
- Duration: Must be 10 days to prevent rheumatic fever 1, 2, 3
- Child becomes non-contagious after 24 hours of therapy 2
Ear Infections (Otitis Media):
- Standard dose: 45 mg/kg/day (315mg twice daily) 1
- High dose: 90 mg/kg/day (630mg twice daily) if recent antibiotic use within 4-6 weeks or high resistance area 1, 4
Critical Administration Details
- Take at the start of meals to minimize gastrointestinal intolerance 3
- Shake suspension well before each use 3
- Refrigeration is preferable but not required 3
- Discard unused suspension after 14 days 3
- Continue treatment for minimum 48-72 hours beyond symptom resolution 3
When to Use High-Dose Regimen (90 mg/kg/day)
Use the higher dose if any of these risk factors are present: 1, 4
- Age less than 2 years
- Daycare attendance
- Recent antibiotic use (within past 3 months)
- Geographic area with high pneumococcal resistance (>10%)
- Severe infection presentation
- Incomplete Haemophilus influenzae type b vaccination
Monitoring and Follow-Up
- Clinical improvement should occur within 48-72 hours 1, 2
- If no improvement by 72 hours, reassess diagnosis and consider alternative antibiotics 1, 2
- Complete the full prescribed course even if symptoms improve 1, 2
Common Adverse Effects
- Most common: Diarrhea, nausea, vomiting 1, 2
- Also possible: Rash, urticaria, hypersensitivity reactions 1, 2
- Twice-daily dosing improves adherence compared to three-times-daily regimens 2
Important Clinical Pitfalls to Avoid
- Never use subtherapeutic doses - they fail to achieve adequate tissue concentrations and promote antimicrobial resistance 4
- Do not underdose in viral coinfections - viral coinfection reduces amoxicillin middle ear fluid penetration, making adequate dosing even more critical 5
- Verify suspension concentration before calculating volume - 125mg/5mL vs 250mg/5mL formulations require different volumes 4, 3
- For Group A Strep infections, must complete full 10 days to prevent rheumatic fever, even if symptoms resolve earlier 1, 2, 3