Recommended Amoxicillin Dosage for Streptococcal Pharyngitis
For patients with streptococcal pharyngitis, amoxicillin should be administered at 50 mg/kg once daily (maximum 1,000 mg) or alternatively 25 mg/kg twice daily (maximum 500 mg per dose) for 10 days. 1
Dosing Recommendations by Age Group
Children
- 50 mg/kg once daily (maximum 1,000 mg) for 10 days 1
- Alternative: 25 mg/kg twice daily (maximum 500 mg per dose) for 10 days 1
Adolescents and Adults
Evidence Strength
- The recommended dosing regimen carries a "Strong, high" recommendation based on quality evidence 1
- Once-daily dosing has been shown to be as effective as twice-daily dosing in multiple clinical trials 4, 3
Important Considerations
Duration of Therapy
- A full 10-day course is essential to prevent acute rheumatic fever, even if symptoms resolve earlier 1, 2
- Patients are generally considered non-contagious after 24 hours of antibiotic therapy 1
Alternative Regimens for Penicillin-Allergic Patients
- Cephalexin: 20 mg/kg twice daily (maximum 500 mg per dose) for 10 days 1
- Clindamycin: 7 mg/kg three times daily (maximum 300 mg per dose) for 10 days 1
- Azithromycin: 12 mg/kg once daily (maximum 500 mg) for 5 days 1
- Note: Macrolide resistance is well-known and varies geographically 1, 5
Special Situations
- For chronic carriers with recurrent symptoms, different regimens may be required 1
- Amoxicillin/clavulanate (40 mg/kg/day of amoxicillin component in three divided doses) may be considered for chronic carriers 1, 6
Common Pitfalls to Avoid
- Shorter courses (<10 days) are not recommended as they may not prevent acute rheumatic fever 2, 7
- Failure to complete the full 10-day course even when symptoms resolve quickly 1
- Not accounting for local resistance patterns when selecting alternatives to amoxicillin 1, 5
- Using macrolides in areas with high resistance rates 5, 6
Advantages of Amoxicillin
- Once-daily dosing may improve adherence compared to multiple daily doses 4, 3
- Amoxicillin has a narrow spectrum of activity with few adverse effects 1
- More palatable than penicillin V suspension, especially for children 1
Remember that confirmation of group A streptococcal pharyngitis through rapid antigen detection testing or throat culture is recommended before initiating antimicrobial therapy to avoid unnecessary antibiotic use 1.