What is the recommended treatment for strep pharyngitis?

Treatment of Strep Pharyngitis

Penicillin remains the first-line treatment for group A streptococcal pharyngitis due to its proven efficacy, safety, narrow spectrum, and low cost. 1

First-Line Treatment Options

• Oral Penicillin V: 500 mg 2-3 times daily for adults for 10 days 1, 2
• Amoxicillin: Can be used in place of penicillin V, particularly for young children due to better taste acceptance 1
  • Dosing: 50 mg/kg once daily (maximum 1000 mg) or 25 mg/kg twice daily (maximum 500 mg per dose) for 10 days 2
• Intramuscular Benzathine Penicillin G: Single dose option (1,200,000 units for patients >60 lb; 600,000 units for patients <60 lb) 2
  • Particularly valuable when compliance with oral therapy is a concern or in areas with high rheumatic fever prevalence 3

Treatment for Penicillin-Allergic Patients

Non-Anaphylactic Penicillin Allergy

• First-generation cephalosporins (e.g., cephalexin 20 mg/kg twice daily, maximum 500 mg per dose, for 10 days) 2

Anaphylactic Penicillin Allergy

• Clindamycin: 7 mg/kg three times daily (maximum 300 mg per dose) for 10 days 2
• Azithromycin: 12 mg/kg once daily (maximum 500 mg) for 5 days 2, 4
  • Note: FDA data shows azithromycin was clinically and microbiologically superior to penicillin in pharyngitis treatment, with 95% bacteriologic eradication at day 14 compared to 73% for penicillin 4
• Clarithromycin: 7.5 mg/kg twice daily (maximum 250 mg per dose) for 10 days 2

Treatment Duration and Compliance

• Standard duration: 10 days for most antibiotics to prevent acute rheumatic fever 1, 5
• Exception: Azithromycin is given for 5 days 2, 4
• Compliance considerations:
  • Twice-daily dosing of penicillin is as effective as more frequent dosing and may improve compliance 6
  • Once-daily dosing of penicillin is associated with decreased efficacy and should not be used 6
  • Once-daily amoxicillin may be effective and could become an alternative if confirmed by additional studies 1

Clinical Pearls and Pitfalls

• Patients are considered non-contagious after 24 hours of antibiotic therapy 2
• Symptoms typically improve within 24-48 hours after starting treatment 2
• Complete the full course of antibiotics even if symptoms resolve quickly to prevent complications and recurrence 2
• Treatment failure considerations: If symptoms persist or worsen after 5 days of appropriate treatment, consider:
  • Non-compliance with the prescribed regimen
  • Penicillin treatment failure (bacteriologic failure rates have increased from 2-10% in the 1970s to approximately 30% more recently) 7
  • New infection with group A streptococci
  • Viral pharyngitis in a streptococcal carrier 2

Follow-Up Recommendations

• Routine follow-up testing (culture or rapid antigen detection test) is not recommended for asymptomatic patients after completing treatment 1
• Routine testing of asymptomatic household contacts is not recommended 1
• For recurrence shortly after treatment completion, consider:
  • Retreatment with the same antibiotic used initially
  • If compliance with oral therapy is questionable, consider intramuscular benzathine penicillin G 1

The evidence strongly supports penicillin as the treatment of choice for strep pharyngitis, with several well-established alternatives for penicillin-allergic patients. Despite some evidence suggesting increased failure rates with penicillin in recent decades, it remains the recommended first-line therapy due to its long track record of safety, efficacy, and the absence of documented resistance.