Amoxicillin Dosing for Strep Throat in a 30-Pound Child
For a 30-pound (13.6 kg) child with strep throat, administer amoxicillin 50 mg/kg once daily (680 mg, maximum 1000 mg) or 25 mg/kg twice daily (340 mg per dose, maximum 500 mg per dose) for 10 days. 1
Recommended Dosing Regimen
The American Academy of Family Physicians recommends amoxicillin as the preferred first-line treatment for Group A Streptococcal pharyngitis in children. 1 For this 30-pound (13.6 kg) child, you have two equivalent options:
Option 1: Once-Daily Dosing (Preferred for Adherence)
- 680 mg once daily (50 mg/kg × 13.6 kg = 680 mg) 1
- This simplifies administration and may improve compliance 2
Option 2: Twice-Daily Dosing
- 340 mg twice daily (25 mg/kg × 13.6 kg = 340 mg per dose) 1
- Both regimens have demonstrated equivalent efficacy 2
Critical Treatment Duration
Complete the full 10-day course regardless of symptom resolution. 1, 3 This duration is essential to prevent acute rheumatic fever, even if the child becomes asymptomatic after 2-3 days. 3 Treatment should continue for at least 48-72 hours beyond symptom resolution. 3
Practical Formulation Guidance
For a 680 mg once-daily dose using oral suspension:
- Using 250 mg/5 mL suspension: Give 13.6 mL once daily
- Using 125 mg/5 mL suspension: Give 27.2 mL once daily
For 340 mg twice-daily dosing:
- Using 250 mg/5 mL suspension: Give 6.8 mL twice daily
- Using 125 mg/5 mL suspension: Give 13.6 mL twice daily
Important Administration Details
- Give at the start of meals to minimize gastrointestinal intolerance 3
- Shake suspension vigorously before each use 3
- Refrigeration is preferable but not required 3
- Discard any unused suspension after 14 days 3
Common Pitfalls to Avoid
Do not use the older 40 mg/kg/day dosing regimen that appears in some references for otitis media. 4 The current guideline-recommended dosing for strep throat is specifically 50 mg/kg once daily or 25 mg/kg twice daily. 1
Avoid once-daily penicillin V as an alternative, as it has shown inferior eradication rates compared to twice-daily dosing. 5 If switching from amoxicillin, penicillin V must be given at least twice daily. 5
When to Consider Alternatives
Reserve amoxicillin/clavulanate (Augmentin) for treatment failures or chronic carriers who have failed first-line therapy, not for initial treatment. 1 For penicillin-allergic patients, consider cephalexin, clindamycin, or azithromycin instead. 1