What is the first line treatment for pharyngitis?

First-Line Treatment for Pharyngitis

Penicillin or amoxicillin for 10 days is the first-line treatment for Group A streptococcal (GAS) pharyngitis, based on proven efficacy, narrow spectrum, safety, low cost, and absence of documented resistance. 1

Diagnostic Confirmation Required First

• Do not treat pharyngitis empirically without testing - clinical features alone cannot reliably distinguish viral from bacterial causes 2
• Perform rapid antigen detection test (RADT) or throat culture to confirm GAS before initiating antibiotics 1, 2
• A positive RADT is diagnostic and requires no backup culture 2
• Negative RADT in children/adolescents should be followed by throat culture 2
• Testing is not recommended for children <3 years old (acute rheumatic fever is rare in this age group) or for patients with clear viral features (cough, rhinorrhea, hoarseness, oral ulcers) 1

First-Line Antibiotic Regimens (Non-Allergic Patients)

Penicillin V remains the gold standard due to its narrow spectrum and proven track record 1:

• Adults: 250 mg four times daily OR 500 mg twice daily for 10 days 2
• Children: Weight-based dosing for 10 days 1

Amoxicillin is equally effective and often preferred for children 1:

• 50 mg/kg once daily (maximum 1000 mg) for 10 days 1, 2
• Once-daily dosing enhances adherence compared to penicillin V 1
• More palatable suspension for young children 1

Intramuscular benzathine penicillin G for patients with adherence concerns 1:

• 1.2 million units as single dose 2
• Preferred when completion of 10-day oral course is unlikely 1

Penicillin-Allergic Patients: Treatment Algorithm

Non-Immediate (Non-Anaphylactic) Penicillin Allergy

First-generation cephalosporins are preferred (strong, high-quality evidence) 1, 3:

• Cephalexin: 20 mg/kg/dose twice daily (maximum 500 mg/dose) for 10 days 1, 3
• Cefadroxil: 30 mg/kg once daily (maximum 1 gram) for 10 days 1, 3
• Cross-reactivity risk is only 0.1% in non-immediate reactions 3

Immediate/Anaphylactic Penicillin Allergy

Avoid all beta-lactams (including cephalosporins) due to up to 10% cross-reactivity risk 1, 3

Clindamycin is the preferred choice (strong, moderate-quality evidence) 1, 3:

• 7 mg/kg/dose three times daily (maximum 300 mg/dose) for 10 days 1, 3
• Only ~1% resistance rate among GAS in the United States 3
• Highly effective even in chronic carriers 3

Macrolide alternatives (strong, moderate-quality evidence but resistance concerns) 1:

• Azithromycin: 12 mg/kg once daily (maximum 500 mg) for 5 days 1, 3
  • Only antibiotic requiring just 5 days due to prolonged tissue half-life 1, 3
  • 5-8% macrolide resistance in the United States (varies geographically) 3
• Clarithromycin: 7.5 mg/kg/dose twice daily (maximum 250 mg/dose) for 10 days 1, 3

Critical Treatment Duration Requirements

The full 10-day course is essential for all antibiotics except azithromycin 1, 2:

• Maximizes pharyngeal eradication of GAS 1, 2
• Prevents acute rheumatic fever 1, 2
• Shortening courses increases treatment failure rates 1

Do not use shorter courses of cephalosporins despite FDA approval for some agents (cefdinir, cefpodoxime) - insufficient evidence and broader spectrum than necessary 1

Adjunctive Therapy

Analgesics/antipyretics for symptom relief (strong, high-quality evidence) 1, 2:

• Acetaminophen or NSAIDs for moderate to severe symptoms or high fever 1, 2
• Avoid aspirin in children due to Reye syndrome risk 1, 2

Corticosteroids are not recommended 1

Antibiotics to AVOID for GAS Pharyngitis

• Tetracyclines: High prevalence of resistant strains 1
• Sulfonamides/trimethoprim-sulfamethoxazole: Do not eradicate GAS 1
• Older fluoroquinolones (ciprofloxacin): Limited activity against GAS 1
• Newer fluoroquinolones (levofloxacin, moxifloxacin): Unnecessarily broad spectrum and expensive 1

Common Pitfalls to Avoid

• Do not treat without diagnostic confirmation - most pharyngitis is viral and self-limited 1, 2
• Do not prescribe cephalosporins to patients with immediate/anaphylactic penicillin reactions - 10% cross-reactivity risk 1, 3
• Do not shorten antibiotic courses below 10 days (except azithromycin's 5-day regimen) - increases treatment failure and rheumatic fever risk 1, 2
• Do not use broad-spectrum cephalosporins when narrow-spectrum agents are appropriate - increases cost and antibiotic resistance 1
• Do not perform routine post-treatment cultures in asymptomatic patients who completed therapy 1, 2
• Do not test or treat asymptomatic household contacts 1

Special Considerations

Recurrent pharyngitis: Patients may be experiencing multiple true infections OR may be chronic carriers with viral infections 1, 3

Chronic carriers: Generally do not require treatment - unlikely to spread infection or develop complications 1, 3

Macrolide resistance: Check local resistance patterns before prescribing azithromycin or clarithromycin 3