What is the first-line treatment for bacterial pharyngitis?

First-Line Treatment for Bacterial Pharyngitis

Penicillin or amoxicillin is the first-line treatment for bacterial (Group A Streptococcal) pharyngitis, with a recommended course of 10 days to ensure bacterial eradication and prevent complications. 1

Diagnosis Before Treatment

Before initiating treatment, proper diagnosis is essential:

• Use Centor Criteria to assess likelihood of GAS pharyngitis:

  • Fever history
  • Tonsillar exudates
  • Absence of cough
  • Tender anterior cervical lymphadenopathy 1, 2

• Rapid Antigen Detection Tests (RADTs) should be considered for patients with 2-4 Centor criteria 1, 2

• Throat cultures are not routinely recommended for adults when using high-sensitivity rapid tests 2

First-Line Treatment Options

For Non-Allergic Patients:

• Penicillin V:

  • Remains the gold standard first-line therapy as recommended by the American Academy of Pediatrics and American Heart Association 3
  • Maintains excellent efficacy with no documented resistance 1, 3

• Amoxicillin:

  • Equally effective alternative with better taste (improving compliance)
  • Dosing options:
    • Adults: 500 mg twice daily for 10 days
    • Children: 50 mg/kg once daily (maximum 1000 mg) or 25 mg/kg twice daily (maximum 500 mg per dose) for 10 days 1

For Penicillin-Allergic Patients:

• First-line alternatives:
  • Erythromycin (traditional recommendation) 3, 2
  • Clindamycin: 300-450 mg orally three times daily for 10 days 1
  • Azithromycin: 12 mg/kg once daily (max 500 mg) for 5 days 1
  • First-generation cephalosporins (if no anaphylactic reaction to penicillin) 4

Treatment Duration

• 10-day course is standard for penicillin and most antibiotics to:

  • Ensure bacterial eradication
  • Prevent transmission
  • Reduce risk of rheumatic fever 1

• Exceptions: 5-day regimens are FDA-approved for certain antibiotics:

  • Azithromycin (5 days)
  • Cefpodoxime (5 days) 3

Management of Treatment Failure

• Penicillin treatment failures occur in 5-35% of cases 3
• For patients who fail initial penicillin treatment:
  • Switch to antibiotics not inactivated by penicillinase-producing organisms:
    • Amoxicillin-clavulanate
    • Cephalosporins
    • Macrolides 5

Supportive Care

• Analgesics/antipyretics for symptom relief:
  • NSAIDs are more effective than acetaminophen for fever and pain 4
  • Medicated throat lozenges every two hours can provide relief 4
• Maintain adequate hydration 1
• Avoid aspirin in children (risk of Reye syndrome) 1

Return to School/Work

• Patients are considered non-contagious after 24 hours of effective antibiotic therapy
• May return to school/work after 24 hours of antibiotics if fever has resolved and they feel well enough 1

Common Pitfalls

1. Overdiagnosis and overtreatment: Only 5-15% of adult sore throats and 15-30% of pediatric cases are caused by GABHS 3, 4
2. Inadequate treatment duration: Not completing the full 10-day course increases risk of rheumatic fever 1
3. Treating viral pharyngitis with antibiotics: Most cases of pharyngitis are viral and self-limiting 2
4. Failure to consider penicillin treatment failure: Consider alternative antibiotics if symptoms worsen or don't improve after 48-72 hours 1