Augmentin Dosing for a 14-Year-Old
For a 14-year-old weighing ≥40 kg, use Augmentin 875 mg/125 mg twice daily; if <40 kg, use 45 mg/kg/day of the amoxicillin component divided every 12 hours (or 40 mg/kg/day divided every 8 hours) for severe infections. 1, 2, 3
Weight-Based Dosing Algorithm
The critical determinant is whether the adolescent weighs ≥40 kg or <40 kg:
For Patients ≥40 kg (Most 14-Year-Olds)
- Standard dosing: 875 mg/125 mg twice daily for most infections 1, 2, 3
- High-dose regimen: 2000 mg/125 mg twice daily when antibiotic resistance is suspected, including recent antibiotic use within 30 days, treatment failure, or high community resistance rates 2
- Maximum daily amoxicillin dose should not exceed 4000 mg 1
For Patients <40 kg
- Severe infections: 45 mg/kg/day divided every 12 hours OR 40 mg/kg/day divided every 8 hours 2, 3
- Mild-to-moderate infections: 25 mg/kg/day divided every 12 hours OR 20 mg/kg/day divided every 8 hours 2, 3
- High-dose formulation: 90 mg/kg/day of amoxicillin with 6.4 mg/kg/day of clavulanate in two divided doses for resistant organisms or β-lactamase-producing pathogens 1, 2
Infection-Specific Considerations
Respiratory Tract Infections
- Use 875 mg/125 mg twice daily for 10-14 days in adolescents ≥40 kg 1
- For suspected resistant Streptococcus pneumoniae or β-lactamase-producing H. influenzae, consider high-dose formulations 2, 4
- Treatment courses of 10 days are well-studied, though shorter courses may be effective for milder disease 5
Skin and Soft Tissue Infections
- For methicillin-susceptible Staphylococcus aureus: 875 mg/125 mg twice daily (if ≥40 kg) or 25 mg/kg/day in 2 divided doses (if <40 kg) 1
Sinusitis
- Standard: 875 mg/125 mg twice daily for 10-14 days 6
- High-dose: 2000 mg/125 mg twice daily if treatment failure after 3-5 days or suspected resistance 6
Treatment Duration
- Standard course: 10-14 days for most respiratory infections 5, 6
- Minimum duration: Continue for 48-72 hours beyond symptom resolution or bacterial eradication 3
- Streptococcal infections: Minimum 10 days to prevent acute rheumatic fever 3
- Assess clinical response within 48-72 hours; lack of improvement warrants further investigation 5, 2
Critical Pitfalls to Avoid
- Do not use 875 mg tablets in patients with severe renal impairment (GFR <30 mL/min) 3
- Avoid underdosing in areas with high penicillin-resistant S. pneumoniae prevalence (>10%); use high-dose formulations 2
- Take at the start of meals to minimize gastrointestinal intolerance 3
- For patients <40 kg, ensure weight-based dosing calculations are accurate to avoid therapeutic failure 2, 3