What is the first‑line treatment for acute bacterial pharyngitis in a patient without a penicillin allergy who has typical symptoms and a positive Group A Streptococcus test?

First-Line Treatment for Acute Bacterial Pharyngitis

For a patient without penicillin allergy who has typical symptoms and a positive Group A Streptococcus test, prescribe oral penicillin V or amoxicillin for a full 10-day course. 1

Specific Dosing Regimens

Adults:

• Penicillin V: 500 mg orally 2–3 times daily for 10 days 1
• Amoxicillin: 1000 mg (1 g) once daily for 10 days 1

Children:

• Penicillin V: 250 mg 2–3 times daily for children < 27 kg; 500 mg 2–3 times daily for children ≥ 27 kg, for 10 days 1
• Amoxicillin: 50 mg/kg once daily (maximum 1000 mg) for 10 days 1

Rationale for This Recommendation

Penicillin and amoxicillin remain the drugs of choice because they offer proven efficacy, narrow antimicrobial spectrum, excellent safety profile, low cost, and no documented penicillin resistance exists worldwide among Group A Streptococcus. 1, 2, 3

The primary goals of treatment are preventing acute rheumatic fever and suppurative complications (peritonsillar abscess, cervical lymphadenitis, mastoiditis), not merely symptom relief. 1 Antibiotics shorten symptom duration by only 1–2 days, but they are critical for preventing serious long-term cardiac and renal sequelae. 4

Why the Full 10-Day Course Is Mandatory

A complete 10-day antibiotic course is essential to achieve maximal pharyngeal eradication of Group A Streptococcus and to prevent acute rheumatic fever. 1 Even if symptoms resolve within 3–4 days, shortening the course by even a few days leads to appreciable increases in treatment failure rates and rheumatic fever risk. 1

Treatment can be safely initiated up to 9 days after symptom onset and still effectively prevent acute rheumatic fever. 1, 4

Alternative Intramuscular Option

Benzathine penicillin G as a single intramuscular injection (600,000 units for patients < 27 kg; 1,200,000 units for patients ≥ 27 kg) is equally effective when adherence to oral therapy is a concern. 1 This avoids the pain and inconvenience of injection but guarantees complete treatment. 1

Adjunctive Symptomatic Treatment

• Acetaminophen or NSAIDs (such as ibuprofen) should be offered for moderate to severe sore throat, fever, or systemic discomfort. 1, 5
• Avoid aspirin in children due to the risk of Reye syndrome. 1
• Corticosteroids are not recommended as adjunctive therapy for streptococcal pharyngitis. 1, 6

Common Pitfalls to Avoid

• Do not prescribe broad-spectrum antibiotics (such as third-generation cephalosporins, fluoroquinolones, or azithromycin) when narrow-spectrum penicillin or amoxicillin is appropriate—these are more expensive and promote antibiotic-resistant flora without added benefit. 1
• Do not order routine post-treatment throat cultures for asymptomatic patients who have completed therapy; testing should be reserved for special circumstances such as a history of rheumatic fever. 1, 4
• Do not test or treat asymptomatic household contacts—up to one-third may be carriers, and prophylactic treatment does not reduce subsequent infection rates. 1, 4

When to Consider Treatment Failure

If the patient shows no clinical improvement within 48–72 hours, consider non-compliance with medication, alternative diagnoses, or suppurative complications requiring imaging and possible drainage. 1 Do not simply switch antibiotics without reassessing the diagnosis. 4