What is the recommended treatment for Streptococcal (Strep) pharyngitis?

Treatment of Streptococcal Pharyngitis

Penicillin V (250 mg three to four times daily, or 500 mg twice daily) for 10 days is the first-line treatment for strep throat in adults and older children, based on its proven efficacy, narrow spectrum, safety, and low cost. 1, 2

First-Line Treatment Options

For Non-Allergic Patients

• Penicillin V remains the drug of choice due to its narrow spectrum of antimicrobial activity, infrequency of adverse reactions, and modest cost, with no documented penicillin resistance among Group A Streptococcus (GAS) ever reported 1

• Dosing for penicillin V:

  • Children: 250 mg twice or three times daily for 10 days 1, 2
  • Adolescents and adults: 250 mg three to four times daily OR 500 mg twice daily for 10 days 1, 2

• Amoxicillin is preferred over penicillin V for younger children at 50 mg/kg once daily (maximum 1000 mg) for 10 days, primarily due to better taste acceptance of the suspension, with equal efficacy to penicillin V 1, 2

• Intramuscular benzathine penicillin G (1.2 million units as a single dose) is preferred when compliance with oral therapy is uncertain, particularly in populations where rheumatic fever remains prevalent or medical follow-up is episodic 1, 3

Critical Treatment Duration

• A full 10-day course is absolutely required to achieve maximal pharyngeal eradication of GAS and prevent acute rheumatic fever—shortening the course by even a few days results in appreciable increases in treatment failure rates 1, 2

• Therapy can be safely postponed up to 9 days after symptom onset and still prevent acute rheumatic fever, but once started, the full 10-day course must be completed 4

Treatment for Penicillin-Allergic Patients

Non-Immediate (Non-Anaphylactic) Penicillin Allergy

• First-generation cephalosporins are the preferred first-line alternatives for patients without immediate hypersensitivity reactions 1, 2, 4

• Specific regimens:

  • Cephalexin: 20 mg/kg per dose twice daily (maximum 500 mg/dose) for 10 days 2, 4
  • Cefadroxil: 30 mg/kg once daily (maximum 1 gram) for 10 days 2, 4

• First-generation cephalosporins have strong, high-quality evidence supporting their efficacy and carry only 0.1% cross-reactivity risk in patients with non-severe, delayed penicillin reactions 4

Immediate/Anaphylactic Penicillin Allergy

• Patients with immediate hypersensitivity (anaphylaxis, angioedema, respiratory distress, or urticaria within 1 hour) must avoid ALL beta-lactam antibiotics including cephalosporins, due to up to 10% cross-reactivity risk 1, 2, 4

• Clindamycin is the preferred alternative at 7 mg/kg per dose three times daily (maximum 300 mg/dose) for 10 days, with approximately 1% resistance rate among GAS isolates in the United States 1, 2, 4

• Macrolide alternatives:

  • Azithromycin: 12 mg/kg once daily (maximum 500 mg) for 5 days only (due to prolonged tissue half-life) 1, 2, 4
  • Clarithromycin: 7.5 mg/kg per dose twice daily (maximum 250 mg/dose) for 10 days 1, 4
  • Erythromycin: 20-40 mg/kg/day divided 2-3 times daily for 10 days (less preferred due to gastrointestinal side effects) 1, 4

Important Resistance Considerations

• Macrolide resistance among GAS is approximately 5-8% in the United States, varying geographically and temporally—be aware of local resistance patterns before prescribing 1, 2, 4

• Clindamycin resistance remains very low at approximately 1% in the United States, making it an excellent choice for penicillin-allergic patients 1, 2, 4

• One study suggests that 10 days of clarithromycin may be more effective than 5 days of azithromycin in eradicating GAS pharyngitis 1

Adjunctive Symptomatic Therapy

• Acetaminophen or NSAIDs (such as ibuprofen) should be considered for moderate to severe symptoms or control of high fever, with strong, high-quality evidence for reducing pain and inflammation 1, 2, 4

• Aspirin must be avoided in children due to the risk of Reye syndrome 1, 2, 4

• Corticosteroids are not recommended as adjunctive therapy—although they may decrease symptom duration by approximately 5 hours, the minimal benefit does not justify potential adverse effects 1, 2

Post-Treatment and Follow-Up

• Routine follow-up throat cultures or rapid antigen detection tests (RADT) are NOT recommended for asymptomatic patients who have completed therapy 1, 2

• Follow-up testing should only be considered in special circumstances, such as patients with a history of rheumatic fever or recurrent symptomatic pharyngitis 1, 2

• Patients become non-contagious after 24 hours of appropriate antibiotic therapy 2

• Diagnostic testing or empiric treatment of asymptomatic household contacts is not routinely recommended, except in specific situations with increased risk of frequent infections or non-suppurative sequelae 1

Common Pitfalls to Avoid

• Do NOT use amoxicillin or ampicillin in patients with concurrent infectious mononucleosis due to risk of rash—use first-generation cephalosporin or macrolide instead 2

• Do NOT prescribe shorter courses than recommended (except for azithromycin's 5-day regimen)—this leads to treatment failure and complications 2, 4

• Do NOT assume all penicillin-allergic patients cannot receive cephalosporins—only those with immediate/anaphylactic reactions should avoid them 2, 4

• Do NOT use sulfonamides, tetracyclines, or trimethoprim-sulfamethoxazole due to high resistance rates (approximately 50% for trimethoprim-sulfamethoxazole) among GAS 2, 4

• Do NOT use broad-spectrum cephalosporins (such as cefaclor, cefuroxime, cefixime, cefdinir, cefpodoxime) when narrow-spectrum first-generation agents are appropriate—they are more expensive and more likely to select for antibiotic-resistant flora 1, 4

• Do NOT use azithromycin as first-line therapy—it should only be used when penicillin and preferred alternatives cannot be used 4