What is the recommended antibiotic treatment for bacterial pharyngitis?

Antibiotic Treatment for Bacterial Pharyngitis

For confirmed or suspected bacterial pharyngitis, amoxicillin or penicillin V for 10 days is the first-line treatment, with first-generation cephalosporins (cephalexin) for non-anaphylactic penicillin allergy and clindamycin for immediate/anaphylactic penicillin reactions. 1

First-Line Treatment Strategy

Most pharyngitis is viral and requires no antibiotics—watchful waiting with symptomatic treatment is the preferred initial approach. 1 However, when Group A Streptococcus (GAS) is confirmed or highly suspected, antibiotic treatment prevents rheumatic fever (73% risk reduction), suppurative complications like peritonsillar abscess (85% risk reduction), and acute otitis media (70% risk reduction). 1

Primary Antibiotic Choice

• Amoxicillin 500 mg twice daily for 10 days (adults) or 50 mg/kg once daily for 10 days (children, maximum 1000 mg) is the preferred first-line treatment. 1, 2
• Penicillin V is equally effective and remains the gold standard due to proven efficacy, narrow spectrum, safety, and low cost. 1
• No penicillin-resistant GAS has ever been documented worldwide, making these agents reliably effective. 1, 3
• The full 10-day course is essential—even though symptoms resolve in 24-48 hours, completing the course maximizes pharyngeal eradication and prevents rheumatic fever. 1, 4, 2

Treatment Algorithm for Penicillin-Allergic Patients

Non-Anaphylactic Penicillin Allergy

• First-generation cephalosporins are the preferred alternative: cephalexin 500 mg twice daily for 10 days (adults) or 20 mg/kg twice daily for 10 days (children, maximum 500 mg/dose). 1, 4, 2
• Cross-reactivity risk is only 0.1% in patients with non-severe, delayed penicillin reactions. 4
• Cefadroxil 30 mg/kg once daily for 10 days is an alternative with once-daily dosing advantage. 4
• Cephalosporins show lower relapse rates compared to penicillin (OR 0.55) with similar symptom resolution. 1

Immediate/Anaphylactic Penicillin Allergy

Patients with anaphylaxis, angioedema, respiratory distress, or urticaria within 1 hour of penicillin must avoid all beta-lactams including cephalosporins due to 10% cross-reactivity risk. 1, 4

• Clindamycin 300 mg three times daily for 10 days (adults) or 7 mg/kg three times daily for 10 days (children, maximum 300 mg/dose) is the preferred choice. 1, 4, 2
• Clindamycin has only ~1% resistance among GAS in the United States and demonstrates high efficacy even in chronic carriers. 4
• Azithromycin 500 mg once daily for 5 days (adults) or 12 mg/kg once daily for 5 days (children, maximum 500 mg) is an acceptable alternative. 1, 4, 5
• Clarithromycin 250 mg twice daily for 10 days (adults) or 7.5 mg/kg twice daily for 10 days (children, maximum 250 mg/dose) is another option. 1, 4

Critical Considerations for Macrolides

• Macrolide resistance among GAS ranges from 5-8% in the United States but varies geographically—check local resistance patterns before prescribing. 1, 4
• Azithromycin requires only 5 days due to prolonged tissue half-life, but has higher late bacteriologic recurrence rates (OR 1.31) compared to 10-day penicillin. 1, 4
• Azithromycin showed 95% bacteriologic eradication at Day 14 versus 73% for penicillin V, but this dropped to 77% versus 63% at Day 30. 5
• In areas with high macrolide resistance, cephalexin is preferred over macrolides for penicillin-allergic patients. 1, 4

Common Pitfalls to Avoid

• Do NOT use cephalosporins in patients with immediate hypersensitivity reactions to penicillin—the 10% cross-reactivity risk is unacceptable. 1, 4
• Do NOT shorten antibiotic courses below 10 days (except azithromycin's 5-day regimen)—this increases treatment failure and rheumatic fever risk. 1, 4, 2
• Do NOT use trimethoprim-sulfamethoxazole or tetracyclines—they do not eradicate GAS and have high resistance rates. 1, 4
• Do NOT prescribe broad-spectrum cephalosporins (cefdinir, cefpodoxime) when narrow-spectrum agents work—this unnecessarily increases cost and resistance selection. 3, 2
• Do NOT use azithromycin as first-line therapy when penicillin/amoxicillin can be used—reserve it for documented penicillin allergy. 4, 2

Adjunctive Symptomatic Treatment

• Acetaminophen or NSAIDs (ibuprofen) should be offered for moderate to severe symptoms or high fever. 4, 2
• Avoid aspirin in children due to Reye syndrome risk. 4, 2
• Corticosteroids are not recommended as adjunctive therapy. 4

Post-Treatment Considerations

• Routine follow-up throat cultures or rapid antigen tests are NOT recommended for asymptomatic patients who completed therapy. 1, 4
• Testing should only be considered in special circumstances such as patients with history of rheumatic fever. 4
• Chronic carriers (positive culture without symptoms) generally do not require treatment—they are unlikely to spread infection or develop complications. 4