What is the recommended treatment for strep throat?

Treatment of Strep Throat

Penicillin or amoxicillin for 10 days is the treatment of choice for strep throat in non-allergic patients, based on proven efficacy, narrow spectrum, safety, and low cost. 1, 2

First-Line Treatment for Non-Allergic Patients

Penicillin V remains the gold standard despite reported bacteriologic failure rates of up to 30% in some studies, as it prevents acute rheumatic fever and maintains a narrow spectrum of activity. 1, 3

Dosing Options:

• Adults: Penicillin V 500 mg twice daily OR 250 mg three times daily for 10 days 1, 4, 5
• Children ≥3 months and <40 kg:
  • Mild/moderate infections: 25 mg/kg/day divided every 12 hours OR 20 mg/kg/day divided every 8 hours 1
  • Severe infections: 45 mg/kg/day divided every 12 hours OR 40 mg/kg/day divided every 8 hours 1

Amoxicillin is equally effective and more palatable, particularly for young children, making it an excellent alternative to penicillin V. 1, 4, 6

Amoxicillin Dosing:

• Adults and children ≥40 kg: 500 mg every 12 hours OR 250 mg every 8 hours for mild/moderate infections; 875 mg every 12 hours OR 500 mg every 8 hours for severe infections 1, 6
• Children ≥3 months and <40 kg: 50 mg/kg once daily (maximum 1000 mg) OR 25 mg/kg twice daily (maximum 500 mg/dose) for 10 days 2, 6

Intramuscular benzathine penicillin G should be considered when adherence to oral therapy is unlikely: 600,000 units for patients <60 lbs (27 kg) or 1,200,000 units for patients ≥60 lbs as a single injection. 1, 4

Treatment for Penicillin-Allergic Patients

The choice of alternative antibiotic depends critically on the type of allergic reaction:

For Non-Immediate Hypersensitivity (e.g., rash):

• First-generation cephalosporins are preferred with cross-reactivity risk <3-10%. 2, 4
• Cephalexin 20 mg/kg/dose twice daily for 10 days OR cefadroxil 30 mg/kg once daily for 10 days 1, 4

For Immediate/Anaphylactic Hypersensitivity:

Avoid cephalosporins entirely due to 10% cross-reactivity risk. 2, 4

• Clindamycin is the preferred alternative: 7 mg/kg/dose three times daily (maximum 300 mg/dose) for 10 days 1, 4
• Macrolides are acceptable but have significant resistance concerns:
  • Azithromycin: 12 mg/kg once daily (maximum 500 mg) for 5 days 1, 2
  • Clarithromycin: 7.5 mg/kg/dose twice daily (maximum 250 mg/dose) for 10 days 1

Critical caveat: Geographic and temporal variation in macrolide resistance is well-documented, with some areas reporting >25% clarithromycin-resistant strains that fail eradication in 81-86% of cases. 1, 7 In regions with high macrolide resistance, clindamycin should be strongly preferred over macrolides. 7

Duration of Therapy

All antibiotics except azithromycin require a full 10-day course to achieve maximal pharyngeal eradication and prevent acute rheumatic fever. 1, 2, 6 This recommendation stands despite research suggesting 5-day cephalosporin courses may be effective, as current guidelines have not adopted shorter durations due to insufficient evidence regarding rheumatic fever prevention. 8, 3

Treatment must continue for at least 10 days for any Group A streptococcal infection to prevent acute rheumatic fever, even if symptoms resolve earlier. 1, 6

Adjunctive Symptomatic Treatment

• Acetaminophen or NSAIDs (such as ibuprofen) should be used for moderate to severe symptoms or high fever. 1, 4
• Aspirin must be avoided in children due to Reye syndrome risk. 1, 4
• Corticosteroids are not recommended as adjunctive therapy. 1

Critical Pitfalls to Avoid

• Never use tetracyclines, sulfonamides, or trimethoprim-sulfamethoxazole as they do not effectively eradicate streptococci from the pharynx due to high resistance rates. 2, 4
• Do not use cephalosporins in patients with immediate/anaphylactic penicillin reactions due to 10% cross-reactivity risk. 2, 4
• Do not routinely test or treat asymptomatic household contacts as penicillin prophylaxis has not been shown to reduce subsequent infection rates. 1, 2
• Avoid premature discontinuation before completing the full course, as this increases relapse risk and suppurative complications. 9

Follow-Up Considerations

• Routine posttreatment throat cultures or rapid antigen tests are not recommended. 1, 2
• Reevaluate patients with worsening symptoms after 48-72 hours or symptoms lasting >5 days after treatment initiation. 2
• Chronic carriers generally do not require treatment as they are unlikely to spread infection or develop complications. 4, 10