Amoxicillin Dosing for Group A Streptococcal Pharyngitis

Recommended Dosing Regimens

The American Academy of Pediatrics and Infectious Diseases Society of America recommends amoxicillin 500 mg twice daily for 10 days for adults and adolescents, and 50 mg/kg once daily (maximum 1000 mg) or 25 mg/kg twice daily (maximum 500 mg per dose) for 10 days for children, with strong, high-quality evidence supporting their efficacy 1
The twice-daily regimen significantly improves compliance while maintaining equivalent efficacy in adults 1

The Infectious Diseases Society of America recommends never shortening the 10-day course, even if symptoms resolve earlier, to prevent acute rheumatic fever and ensure adequate bacterial eradication 2
Shortening the course by even a few days results in appreciable increases in treatment failure rates and risk of acute rheumatic fever 2

The American Academy of Pediatrics recommends switching to high-dose amoxicillin-clavulanate (90 mg/kg/day of amoxicillin with 6.4 mg/kg/day of clavulanate in 2 divided doses) if the patient has taken amoxicillin in the previous 30 days, has concurrent purulent conjunctivitis, or requires coverage for beta-lactamase producing organisms 1, 3

For non-immediate penicillin allergy, the Infectious Diseases Society of America recommends first-generation cephalosporins (cephalexin 500 mg twice daily for 10 days in adults; 20 mg/kg/dose twice daily in children) 1, 2
For immediate/anaphylactic penicillin allergy, the Infectious Diseases Society of America recommends clindamycin 300 mg three times daily for 10 days (adults) or 7 mg/kg/dose three times daily (children, maximum 300 mg/dose), or azithromycin 500 mg once daily for 5 days (adults) or 12 mg/kg once daily (children, maximum 500 mg) 1, 2