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

Treatment of Streptococcal Pharyngitis (Strep Throat)

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

Diagnosis

Before initiating treatment, proper diagnosis is essential:

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

  1. Tonsillar exudates
  2. Tender anterior cervical lymph nodes
  3. Lack of cough
  4. 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

• Viral symptoms (cough, rhinorrhea, hoarseness, oral ulcers) make GAS infection unlikely 1

First-Line Treatment Options

Penicillin-Based Regimens (Preferred)

• Oral Penicillin V:

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

• Amoxicillin:

  • 50 mg/kg once daily (maximum 1000 mg) OR
  • 25 mg/kg twice daily (maximum 500 mg per dose)
  • Duration: 10 days 1

• Benzathine Penicillin G (intramuscular):

  • Recommended for patients with anticipated compliance issues 1

Note: Twice-daily dosing of penicillin has been shown to be as effective as more frequent dosing regimens, but once-daily dosing is associated with decreased efficacy and should not be used 2

Alternative Treatments for Penicillin-Allergic Patients

For Non-Anaphylactic Penicillin Allergy:

• 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

For Severe Penicillin Allergy:

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

Important: Resistance to macrolides should be considered. Susceptibility testing should be performed when using azithromycin, as some strains are resistant 3, 4. Data establishing efficacy of azithromycin in subsequent prevention of rheumatic fever are not available 3.

Critical Importance of Completing Full Treatment Course

• The full 10-day course of antibiotics (except for azithromycin, which is 5 days) must be completed to:

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

• Patients should be advised to complete the full course even if symptoms improve before completion 1

Symptomatic Treatment

In addition to antibiotics, symptomatic relief can be provided with:

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

Special Considerations

• Penicillin has been the treatment of choice since the 1950s, but failure rates have increased from 2-10% in the 1970s to approximately 30% more recently 5
• Primary causes of treatment failure include poor compliance with the 10-day regimen, reexposure to infected individuals, and penicillin tolerance 5
• Patients with a history of anaphylaxis, angioedema, or respiratory distress should avoid all β-lactams 1
• For recurrent tonsillitis, tonsillectomy may be considered based on the Paradise criteria (≥7 episodes in 1 year, ≥5 episodes per year for 2 years, or ≥3 episodes per year for 3 years) 1

Prevention of Rheumatic Fever

• Penicillin is considered by the American Heart Association to be the drug of choice in preventing initial attacks of rheumatic fever 4
• For penicillin-allergic patients, erythromycin is recommended for long-term prophylaxis of streptococcal pharyngitis to prevent recurrent attacks of rheumatic fever 4