What is the recommended treatment for strep throat?

Strep Throat Treatment

Penicillin V (250 mg twice or three times daily for 10 days) or amoxicillin (50 mg/kg once daily, maximum 1000 mg, for 10 days) remains the first-line treatment for Group A streptococcal pharyngitis due to proven efficacy, safety, narrow spectrum, and low cost. 1, 2

First-Line Treatment Options

Penicillin-Based Therapy

• Oral penicillin V: Children receive 250 mg twice or three times daily; adolescents and adults receive 250 mg three to four times daily or 500 mg twice daily for 10 days 1
• Amoxicillin: 50 mg/kg once daily (maximum 1000 mg) for 10 days is equally effective and offers improved adherence due to convenient once-daily dosing 1, 2, 3
• Intramuscular benzathine penicillin G: Single dose of 600,000 units for patients <27 kg or 1,200,000 units for patients ≥27 kg—preferred when oral compliance is unlikely 1, 2

Why Penicillin Remains First-Line

• Group A streptococci have shown no resistance to penicillin over five decades 1
• Narrow antimicrobial spectrum minimizes disruption of normal flora 1
• Modest cost compared to alternatives 1
• The 10-day duration is necessary to achieve maximal pharyngeal eradication and prevent acute rheumatic fever 1, 3

Treatment for Penicillin-Allergic Patients

Non-Anaphylactic Penicillin Allergy

• First-generation cephalosporins are first-line alternatives 1, 2, 4:
  • Cephalexin: 20 mg/kg per dose twice daily (maximum 500 mg per dose) for 10 days 1, 4
  • Cefadroxil: 30 mg/kg once daily (maximum 1 g) for 10 days 1, 4
• These should NOT be used in patients with immediate/anaphylactic hypersensitivity to β-lactams due to 10% cross-reactivity risk 1, 2, 4

Immediate/Anaphylactic Penicillin Allergy

• Clindamycin: 7 mg/kg per dose three times daily (maximum 300 mg per dose) for 10 days—demonstrates high efficacy even in chronic carriers with only 1% resistance in the United States 1, 2, 4, 5
• Azithromycin: 12 mg/kg once daily (maximum 500 mg) for 5 days—the only macrolide requiring just 5 days due to prolonged tissue half-life 1, 2, 4, 6
• Clarithromycin: 7.5 mg/kg per dose twice daily (maximum 250 mg per dose) for 10 days 1, 2, 4

Important Caveats for Macrolides

• Macrolide resistance among Group A streptococci is approximately 5-8% in the United States but varies geographically 2, 4
• Check local resistance patterns before prescribing macrolides 4
• Erythromycin (20-40 mg/kg/day divided 2-3 times daily for 10 days) has high gastrointestinal side effects and is less preferred than newer macrolides 1, 7

Treatment Duration and Efficacy

Why 10 Days Matters

• A full 10-day course is required for most antibiotics to achieve maximal pharyngeal eradication of Group A streptococci 1, 2
• The 10-day duration specifically prevents acute rheumatic fever 1, 3
• Shorter courses (3-7 days) of penicillin show inferior outcomes compared to 10 days 1
• Exception: Azithromycin requires only 5 days due to unique pharmacokinetics 1, 2, 4, 6

Evidence on Cephalosporins vs. Penicillin

• Meta-analyses show cephalosporins have slightly higher bacteriologic cure rates than penicillin (OR 2.29-2.34), but clinical differences are small and not clinically relevant 1
• Five-day courses of certain cephalosporins may be as effective as 10-day penicillin, but this cannot be definitively recommended yet 1, 8

Adjunctive Therapy

• Analgesics/antipyretics: Acetaminophen or NSAIDs for moderate to severe symptoms or high fever 1, 2
• Avoid aspirin in children due to Reye syndrome risk 1, 2, 4
• Corticosteroids are NOT recommended as adjunctive therapy 1, 2, 4

Follow-Up and Testing

When NOT to Test

• Routine post-treatment throat cultures or rapid antigen tests are NOT recommended for asymptomatic patients who completed therapy 1, 2, 5
• Routine testing of asymptomatic household contacts is NOT recommended 1

When to Consider Testing

• Patients with recurrent pharyngitis and positive cultures may be chronic carriers experiencing viral infections—antibiotics generally not needed unless specific circumstances exist (community outbreak, family history of rheumatic fever, excessive anxiety) 1
• Follow-up testing may be considered for patients with history of rheumatic fever 4

Recurrent Strep Throat

• If recurrence occurs shortly after completing therapy, retreat with the same antibiotic or switch to intramuscular benzathine penicillin G if oral compliance is questionable 1
• For multiple recurrences, alternative regimens such as clindamycin, amoxicillin-clavulanate, or benzathine penicillin G with rifampin may be more effective 2
• Clindamycin is particularly effective for chronic carriers due to high eradication rates 2, 4, 5

Common Pitfalls to Avoid

• Do not use trimethoprim-sulfamethoxazole for strep throat—high resistance rates (50%) make it ineffective 4
• Do not prescribe shorter courses than recommended (except azithromycin)—leads to treatment failure and complications 4
• Do not assume all penicillin-allergic patients cannot receive cephalosporins—only those with immediate/anaphylactic reactions should avoid them 4
• Do not perform routine post-treatment cultures on asymptomatic patients—this is not recommended and leads to unnecessary treatment 1, 2, 5
• Patients are non-contagious after 24 hours of appropriate antibiotic therapy 2, 5