Treatment of Strep Throat
For patients without penicillin allergy, amoxicillin 50 mg/kg once daily (maximum 1000 mg) for 10 days is the preferred treatment for children, while penicillin V 500 mg twice daily for 10 days is optimal for adults and older children. 1, 2
First-Line Treatment for Non-Allergic Patients
Pediatric Patients (Younger Children)
- Amoxicillin is the drug of choice at 50 mg/kg once daily (maximum 1000 mg) for 10 days due to superior taste acceptance, better compliance, and higher bacteriologic cure rates (79.3% vs 54.5% with standard-dose penicillin V) 1, 3
- The once-daily dosing significantly improves adherence compared to multiple daily doses 1
Adults and Older Children
- Penicillin V 500 mg twice daily for 10 days is the optimal regimen, providing better outcomes than four-times-daily dosing or once-daily dosing 1, 4
- Alternative: Penicillin V 250 mg three to four times daily for 10 days, though twice-daily dosing is preferred for compliance 1
When Compliance is Questionable
- Intramuscular benzathine penicillin G 1.2 million units as a single injection ensures complete treatment and remains the gold standard in settings where follow-up is unreliable or in populations where rheumatic fever is still prevalent 1, 5
Treatment for Penicillin-Allergic Patients
Determine the Type of Allergic Reaction First
Non-immediate/delayed reactions (rash occurring >1 hour after administration, non-urticarial):
- First-generation cephalosporins are safe and preferred with only 0.1% cross-reactivity risk 6
- Cephalexin 500 mg twice daily for 10 days (adults) or 20 mg/kg per dose twice daily for 10 days (children) 6, 1
- Alternative: Cefadroxil 30 mg/kg once daily for 10 days (children) 6
Immediate/anaphylactic reactions (anaphylaxis, angioedema, urticaria, or respiratory distress within 1 hour):
- All beta-lactams must be avoided due to up to 10% cross-reactivity risk 6, 7
- Clindamycin is the preferred alternative at 300 mg three times daily for 10 days (adults) or 7 mg/kg per dose three times daily (maximum 300 mg/dose) for 10 days (children) 6, 1
- Clindamycin has only ~1% resistance among Group A Streptococcus in the United States and demonstrates superior efficacy even in chronic carriers 6
Secondary Alternatives for Immediate Penicillin Allergy
Azithromycin (when clindamycin cannot be used):
- 500 mg once daily for 5 days (adults) or 12 mg/kg once daily (maximum 500 mg) for 5 days (children) 6, 1
- Important limitation: 5-8% macrolide resistance in the United States, with geographic variation 6
- Only antibiotic requiring just 5 days due to prolonged tissue half-life 6
Clarithromycin (acceptable alternative):
- 250 mg twice daily for 10 days (adults) or 7.5 mg/kg per dose twice daily (maximum 250 mg/dose) for 10 days (children) 6
- Same resistance concerns as azithromycin 6
Critical Treatment Duration Requirements
The full 10-day course is mandatory for all antibiotics except azithromycin to achieve maximal pharyngeal eradication and prevent acute rheumatic fever 6, 1, 2. Shortening the course by even a few days dramatically increases treatment failure rates and rheumatic fever risk 6.
Common Pitfalls to Avoid
- Never use cephalosporins in patients with immediate/anaphylactic penicillin reactions due to 10% cross-reactivity risk 6, 7
- Do not assume all penicillin-allergic patients cannot receive cephalosporins - only those with immediate hypersensitivity should avoid them 6
- Avoid using azithromycin or macrolides as first-line when penicillin can be used, as they have inferior spectrum and resistance concerns 6, 1
- Never prescribe trimethoprim-sulfamethoxazole (Bactrim) for strep throat - it has 50% resistance rates and is not effective against Group A Streptococcus 6
- Do not shorten treatment courses below 10 days (except azithromycin's 5-day regimen) as this increases treatment failure and complications 6, 2
- Avoid once-daily penicillin V dosing - it results in 23% recurrent positive cultures vs 8% with twice-daily dosing 4
Adjunctive Symptomatic Treatment
- Acetaminophen or NSAIDs (ibuprofen) for moderate to severe symptoms or high fever 6
- Never use aspirin in children due to Reye syndrome risk 6
- Corticosteroids are not recommended as adjunctive therapy 6
Special Considerations
Recurrent Infections
- Clindamycin may be particularly effective for patients with multiple recurrent episodes due to its superior ability to eradicate streptococci in chronic carriers 6, 7
- Consider benzathine penicillin G for patients with questionable compliance 8
Post-Treatment Testing
- Routine follow-up throat cultures are NOT recommended for asymptomatic patients who completed therapy 6
- Testing should only be considered in special circumstances such as patients with history of rheumatic fever 6