What is the recommended treatment for strep (streptococcal) pharyngitis?

Treatment for Streptococcal Pharyngitis

Penicillin V (250 mg four times daily OR 500 mg twice daily) or amoxicillin (50 mg/kg once daily, maximum 1000 mg) for a full 10 days is the first-line treatment for strep pharyngitis, with penicillin preferred due to its narrow spectrum, proven efficacy, safety profile, and low cost. 1, 2

First-Line Antibiotic Regimens

For non-allergic patients, use one of these penicillin-based regimens:

• Penicillin V: 250 mg four times daily OR 500 mg twice daily for 10 days in adolescents and adults 1, 2, 3
• Amoxicillin: 50 mg/kg once daily (maximum 1000 mg) for 10 days, often preferred in children due to better palatability and once-daily dosing that enhances adherence 1, 2, 3
• Intramuscular benzathine penicillin G: Single dose (600,000 units if <27 kg; 1,200,000 units if ≥27 kg) when adherence to oral therapy is uncertain 2, 3

The 10-day duration is essential for all antibiotics except azithromycin to achieve maximal pharyngeal eradication and prevent acute rheumatic fever. 1, 2, 3 Penicillin resistance has never been documented in Group A Streptococcus. 1

Treatment for Penicillin-Allergic Patients

The choice of alternative antibiotic depends critically on the type of allergic reaction:

Non-Immediate (Non-Anaphylactic) Penicillin Allergy

First-generation cephalosporins are the preferred alternatives:

• Cephalexin: 20 mg/kg per dose twice daily (maximum 500 mg per dose) for 10 days 2, 4
• Cefadroxil: 30 mg/kg once daily (maximum 1 gram) for 10 days 2, 4

These have strong, high-quality evidence supporting their efficacy and carry only 0.1% cross-reactivity risk in patients with non-severe, delayed penicillin reactions. 4

Immediate/Anaphylactic Penicillin Allergy

All beta-lactam antibiotics must be avoided due to up to 10% cross-reactivity risk. 2, 4 Use these alternatives:

• Clindamycin (preferred): 7 mg/kg per dose three times daily (maximum 300 mg per dose) for 10 days 2, 4

  • Approximately 1% resistance rate in the United States 2, 4
  • Particularly effective in chronic carriers or treatment failures 2, 4

• Azithromycin: 12 mg/kg once daily (maximum 500 mg) for 5 days 2, 4, 5

  • Only antibiotic requiring just 5 days due to prolonged tissue half-life 2, 3
  • 5-8% macrolide resistance in the United States 2, 4
  • FDA label notes that "data establishing efficacy of azithromycin in subsequent prevention of rheumatic fever are not available" 5

• Clarithromycin: 7.5 mg/kg per dose twice daily (maximum 250 mg per dose) for 10 days 2, 4

  • Similar resistance concerns as azithromycin 4

• Erythromycin (less preferred): 20-40 mg/kg/day divided 2-3 times daily (maximum 1 gram per day) for 10 days 4, 6

  • High rate of gastrointestinal side effects makes it less desirable 4

Critical Treatment Duration Requirements

Do not shorten the 10-day course for any antibiotic except azithromycin's 5-day regimen. 2, 3 Even though symptoms typically resolve within 24-48 hours of starting therapy, the full course is essential to prevent acute rheumatic fever and achieve maximal bacterial eradication. 1, 2, 3 Therapy can be safely postponed up to 9 days after symptom onset and still prevent rheumatic fever. 4

Adjunctive Therapy

• Acetaminophen or NSAIDs (ibuprofen) for moderate to severe symptoms or high fever 1, 2, 3
• Avoid aspirin in children due to risk of Reye syndrome 1, 2, 3
• Corticosteroids are not recommended 1, 4

Common Pitfalls to Avoid

• Do not treat without confirming diagnosis through rapid antigen detection test (RADT) or throat culture, as clinical features alone cannot reliably distinguish viral from bacterial pharyngitis 3
• Do not use cephalosporins in patients with immediate/anaphylactic penicillin reactions due to 10% cross-reactivity risk 2, 4
• Do not prescribe broad-spectrum antibiotics when narrow-spectrum penicillin is appropriate, as this increases cost and selection pressure for resistant organisms 1, 3
• Do not assume all penicillin-allergic patients cannot receive cephalosporins - only those with immediate/anaphylactic reactions should avoid them 4
• Do not routinely test or treat asymptomatic household contacts given the self-limited nature of the disease and limited efficacy of prophylaxis 1

Follow-Up Recommendations

Routine post-treatment throat cultures or RADT are not recommended for asymptomatic patients who have completed therapy. 1, 3 Testing should only be considered in special circumstances, such as patients with a history of rheumatic fever. 1, 3 Patients with recurrent episodes should be evaluated to determine whether they are experiencing true recurrent infections or are chronic carriers with viral infections. 3