What is the recommended treatment for strep pharyngitis?

Treatment of Strep Pharyngitis

Penicillin or amoxicillin is the recommended first-line treatment for streptococcal pharyngitis due to their narrow spectrum of activity, infrequency of adverse reactions, modest cost, and proven efficacy. 1, 2

First-Line Treatment Options

For Non-Penicillin Allergic Patients:

• Penicillin V:

  • Adults: 500 mg orally 2-3 times daily for 10 days
  • Children: 250 mg orally 2-3 times daily for 10 days 2

• Amoxicillin (alternative first-line, particularly for young children due to better taste):

  • 50 mg/kg once daily (maximum 1000 mg) OR
  • 25 mg/kg twice daily (maximum 500 mg per dose) for 10 days 2

For Penicillin-Allergic Patients:

• Non-anaphylactic allergy:

  • First-generation cephalosporins (e.g., cephalexin 20 mg/kg twice daily, maximum 500 mg per dose) for 10 days 1, 2

• Anaphylactic allergy:

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

Important Clinical Considerations

1. Duration of Therapy:

   • Standard duration is 10 days for most antibiotics to prevent acute rheumatic fever
   • Exception: Azithromycin is given for 5 days due to its longer half-life 2, 3

2. Symptom Relief:

   • Acetaminophen or ibuprofen for pain/fever control
   • Avoid aspirin in children due to risk of Reye syndrome 1, 2
   • Corticosteroids are not routinely recommended 1

3. Return to Normal Activities:

   • Patients are considered non-contagious after 24 hours of antibiotic therapy
   • Symptoms typically improve within 24-48 hours after starting treatment 2

4. Follow-up Testing:

   • Routine post-treatment throat cultures are not recommended 1

Special Situations

Recurrent Strep Pharyngitis

• Consider whether the patient is experiencing true recurrences or is a chronic carrier with viral infections 1
• For multiple recurrences, investigation for chronic carriers in the household may be necessary 2

Treatment Failures

• Penicillin failure rates have increased over time and may now be approximately 30% 4
• Causes of treatment failure include:
  • Poor compliance with the 10-day regimen
  • Reexposure to infected family members
  • Copathogenicity with other bacteria
  • Penicillin tolerance 4

Caveats and Pitfalls

1. Antibiotic Resistance:

   • Significant resistance to azithromycin and clarithromycin exists in some parts of the US 5
   • About 1% of azithromycin-susceptible S. pyogenes isolates may become resistant following therapy 3

2. Diagnostic Considerations:

   • Testing for GAS pharyngitis is not recommended for children <3 years old 1
   • Testing is not recommended when clinical features strongly suggest viral etiology (cough, rhinorrhea, hoarseness, oral ulcers) 1

3. Compliance Issues:

   • Once-daily amoxicillin regimens may improve compliance while maintaining efficacy 6
   • Poor compliance is a major factor in treatment failure 4

4. Treatment of Household Contacts:

   • Diagnostic testing or empiric treatment of asymptomatic household contacts is not routinely recommended 1

By following these evidence-based recommendations, clinicians can effectively treat strep pharyngitis while minimizing complications and antibiotic resistance.