What are the treatment options for augmenting strep A (streptococcal) tonsillitis?

Treatment Options for Strep A Tonsillitis

Penicillin V remains the first-line treatment for Group A Streptococcal (GAS) tonsillitis due to its proven effectiveness, narrow spectrum of activity, and lack of documented resistance worldwide.

First-Line Treatment Options

Penicillin V (First Choice)

• Dosage for children: 250 mg 2-3 times daily for 10 days 1
• Dosage for adolescents/adults: 500 mg 2-3 times daily for 10 days 1, 2
• Key benefits:
  • Narrow spectrum of activity (minimizes antimicrobial resistance) 1
  • No documented GAS resistance worldwide 1
  • Generally less expensive than alternatives 1

Amoxicillin (Alternative First-Line)

• Dosage: 50 mg/kg once daily (maximum 1000 mg) or 25 mg/kg twice daily (maximum 500 mg per dose) for 10 days 2, 1
• Advantages: Once-daily dosing may improve compliance 1
• Caution: Avoid in suspected Epstein-Barr virus (EBV) infection due to risk of severe rash 1

Benzathine Penicillin G (Intramuscular Option)

• Dosage: 600,000 units for patients <27 kg; 1,200,000 units for patients ≥27 kg (single dose) 2
• Consider when: Oral compliance is a concern or for patients with history of rheumatic fever 2, 1

Options for Penicillin-Allergic Patients

Non-Anaphylactic Penicillin Allergy

• Cephalexin: 20 mg/kg twice daily (maximum 500 mg per dose) for 10 days 2, 1
• Cefadroxil: 30 mg/kg once daily (maximum 1 g) for 10 days 2

Anaphylactic Penicillin Allergy

• Clindamycin: 7 mg/kg three times daily (maximum 300 mg per dose) for 10 days 2, 1
• Azithromycin: 12 mg/kg once daily (maximum 500 mg) for 5 days 2, 3
• Clarithromycin: 7.5 mg/kg twice daily (maximum 250 mg per dose) for 10 days 2, 1

Treatment for Persistent or Recurrent Cases

For Chronic Carriers

When eradication of carriage is necessary (e.g., during outbreaks, family history of rheumatic fever):

• Clindamycin: 20-30 mg/kg/day in 3 doses (maximum 300 mg per dose) for 10 days 2
• Amoxicillin-clavulanate: 40 mg/kg/day in 3 doses (maximum 2000 mg amoxicillin/day) for 10 days 2
• Penicillin V with rifampin: Penicillin V for 10 days plus rifampin 20 mg/kg/day for the last 4 days of treatment 2

Clinical Considerations and Pitfalls

Treatment Duration

• Complete the full 10-day course of penicillin or other beta-lactams even if symptoms resolve earlier, to prevent complications like acute rheumatic fever 2, 1
• Shorter courses (5 days) are only validated for certain antibiotics like azithromycin 3

Compliance Issues

• Twice-daily dosing of penicillin is as effective as more frequent dosing regimens and may improve compliance 4
• Once-daily dosing of penicillin is associated with decreased efficacy (12 percentage points lower cure rate) and should be avoided 4
• Consider intramuscular benzathine penicillin G for patients with suspected compliance issues 2

Treatment Failures

• Penicillin failure rates have increased from 2-10% in the 1970s to approximately 30% currently 5
• Primary causes of treatment failure:
  • Poor compliance with the 10-day regimen 5
  • Reexposure to infected family members 5
  • Copathogenicity with other bacteria 5
  • Eradication of normal protective pharyngeal flora 5

When to Consider Alternative Antibiotics

• After treatment failure with appropriate first-line therapy 2
• When distinguishing between carrier state with viral infection versus true GAS infection is difficult 2
• In areas with high macrolide resistance, avoid clarithromycin and azithromycin 6

Important Reminders

• Patients are considered non-contagious after 24 hours of antibiotic therapy 1
• Symptoms typically improve within 24-48 hours after starting treatment 1
• GAS carriers (asymptomatic individuals with positive throat cultures) generally do not require antimicrobial therapy 2, 1
• Tonsillectomy is not recommended solely to reduce the frequency of GAS pharyngitis 2

By following these evidence-based recommendations, clinicians can effectively treat strep A tonsillitis while minimizing complications and antimicrobial resistance.