What is the recommended treatment for bacterial pharyngitis?

Treatment of Bacterial Pharyngitis

The recommended first-line treatment for bacterial pharyngitis is oral penicillin V (250 mg 2-3 times daily for children, 500 mg 2-3 times daily for adults) or amoxicillin (50 mg/kg once daily, maximum 1000 mg) for a full 10-day course. 1

Diagnosis Before Treatment

Before initiating treatment, proper diagnosis is essential:

• Use Centor Criteria to assess likelihood of Group A Streptococcal (GAS) infection:

  • Tonsillar exudates
  • Tender anterior cervical lymph nodes
  • Lack of cough
  • Fever

• Patients with 0-2 criteria are unlikely to have GAS infection and don't require testing

• Patients with 3-4 criteria should be tested with rapid antigen detection test (RADT) and/or throat culture 1

First-Line Treatment Options

1. Penicillin V:

   • Children: 250 mg 2-3 times daily for 10 days
   • Adults: 500 mg 2-3 times daily for 10 days 1

2. 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

Important: It is recommended that there be at least 10 days' treatment for any infection caused by Streptococcus pyogenes to prevent the occurrence of acute rheumatic fever. 2

Alternative Treatments for Penicillin Allergy

For patients with penicillin allergy, the following alternatives are recommended:

1. Cephalosporins (if no history of anaphylaxis to penicillin):

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

2. Clindamycin:

   • 7 mg/kg three times daily (maximum 300 mg per dose) for 10 days 1
   • Children: 20-30 mg/kg/day in 3 equally divided doses for 10 days
   • Adults: 600 mg/day in 2-4 equally divided doses for 10 days 3

3. Macrolides:

   • Azithromycin: 12 mg/kg once daily (maximum 500 mg) for 5 days 1, 4
   • Clarithromycin: 7.5 mg/kg twice daily (maximum 250 mg per dose) for 10 days 1

Note: Azithromycin has shown clinical and microbiological superiority to penicillin in some studies, with a 95% bacteriologic eradication rate compared to 73% for penicillin V at day 14 4. However, macrolides should be used with consideration of local resistance patterns.

Treatment Duration

• Complete the full 10-day course of antibiotics (except for azithromycin, which is 5 days) to:

  • Prevent acute rheumatic fever
  • Ensure complete eradication of Group A Streptococcus
  • Reduce risk of treatment failure 1

• Shorter courses (5 days) have been associated with higher bacteriologic treatment failure rates (18% vs 6% for 10-day courses) 5

Symptomatic Treatment

In addition to antibiotics, the following symptomatic treatments can help alleviate discomfort:

• NSAIDs or acetaminophen for pain and fever
• Warm salt water gargles
• Throat lozenges 1

Management of Treatment Failures

For patients who experience treatment failure or have recurrent episodes:

• Oral Clindamycin or Amoxicillin-clavulanic acid may be used for treatment failures 3

• Tonsillectomy should be considered only for recurrent tonsillitis based on the Paradise criteria:

  • ≥7 well-documented, adequately treated episodes in the preceding year, OR
  • ≥5 such episodes in each of the preceding 2 years, OR
  • ≥3 such episodes in each of the preceding 3 years 1

Common Pitfalls to Avoid

1. Inadequate treatment duration: Failing to complete the full 10-day course of antibiotics increases risk of treatment failure and complications like rheumatic fever.

2. Inappropriate antibiotic selection: Using broad-spectrum antibiotics when not indicated contributes to antibiotic resistance.

3. Treating viral pharyngitis with antibiotics: Patients with viral symptoms (cough, rhinorrhea, hoarseness, oral ulcers) are unlikely to have GAS infection and do not require antibiotic treatment.

4. Routine follow-up cultures: These are not recommended for asymptomatic patients who have received adequate treatment 3.

5. Routine testing of asymptomatic family contacts: This practice should be avoided 3.