What antibiotics treat streptococcal per hemolytic infections?

Treatment of Beta-Hemolytic Streptococcal Infections

Penicillin or amoxicillin remains the first-line treatment for beta-hemolytic streptococcal infections due to its proven efficacy, narrow spectrum, absence of resistance, and cost-effectiveness. 1

First-Line Treatment Options

For Streptococcal Pharyngitis

• Penicillin V: First-line therapy for 10 days 1
• Amoxicillin: 50 mg/kg once daily (maximum 1000 mg) or 25 mg/kg twice daily (maximum 500 mg per dose) for 10 days 1, 2
  • Particularly effective for streptococcal infections of the upper respiratory tract, skin, and lower respiratory tract 2

Duration of Therapy

• 10-day course is mandatory for streptococcal pharyngitis to prevent acute rheumatic fever 1, 2
• Treatment should continue for at least 10 days for any infection caused by Streptococcus pyogenes to prevent acute rheumatic fever 2

Alternative Treatments (For Penicillin-Allergic Patients)

For Mild-Moderate Infections

• Clindamycin: 600-900 mg/kg every 8 hours (for adults) 3, 4
• Azithromycin: 12 mg/kg once daily (maximum 500 mg) for 5 days 1

For Severe Infections

• Clindamycin: 600-1,200 mg per day in 2,3, or 4 equal doses for serious infections; can be increased to 1,200-2,700 mg per day for more severe infections 4
• Vancomycin: For patients intolerant of β-lactam therapy 3

Special Considerations

Mixed Infections

For necrotizing fasciitis with mixed infection (including beta-hemolytic streptococci):

• Combination therapy: Ampicillin-sulbactam plus clindamycin plus ciprofloxacin 3
• Alternative: Imipenem/cilastatin, meropenem, or ertapenem 3

Streptococcal Toxic Shock Syndrome

• Clindamycin plus penicillin: Recommended for necrotizing fasciitis and/or toxic shock syndrome caused by group A streptococci 3
  • Clindamycin suppresses toxin production and modulates cytokine production 3

Treatment Considerations by Site of Infection

Skin and Soft Tissue Infections

• For non-purulent cellulitis (likely beta-hemolytic streptococcal infection):
  • First-line: Beta-lactam antibiotics 3
  • Duration: 5-10 days, individualized based on clinical response 3

Streptococcal Pharyngitis

• Contagious period: Until 24 hours of appropriate antibiotic therapy 1
• Diagnosis: Use Centor Criteria (tonsillar exudates, tender anterior cervical lymph nodes, lack of cough, fever) 1
• Testing: RADT or throat culture for confirmation 1

Treatment Failures

• Clinical failure rates with penicillin range from 6% to 25% 5, 6
• For treatment failures:
  • Consider cephalosporins or azithromycin 6
  • Cephalosporins may have lower clinical failure rates compared to penicillin in some studies 7, 8

Pitfalls and Caveats

1. Complete the full course: Failure to complete the full 10-day course of antibiotics (except for azithromycin which is 5 days) increases risk of complications such as acute rheumatic fever 1

2. Misdiagnosis: Physicians often overdiagnose streptococcal pharyngitis, leading to unnecessary antibiotic use. Use throat cultures and/or rapid GABHS detection tests for confirmation 6

3. Resistance concerns: While penicillin resistance has not been documented in beta-hemolytic streptococci, treatment failures may occur due to:

   • Co-pathogen colonization
   • Recent antibiotic exposure
   • Poor compliance 6

4. Supportive care: Don't forget symptomatic relief with cold liquids, throat lozenges, and NSAIDs for pain and fever 1

5. Prevention of complications: Primary prevention of acute rheumatic fever requires proper identification and adequate antibiotic treatment of streptococcal infections 1

Despite newer antibiotics, penicillin remains the drug of choice for beta-hemolytic streptococcal infections due to its continued effectiveness, safety profile, narrow spectrum, and lack of resistance development 9, 8.