What is the recommended treatment for strep throat?

Treatment for Strep Throat

Penicillin V or amoxicillin for 10 days remains the first-line treatment for strep throat due to proven efficacy, narrow spectrum, safety, and low cost, with no documented resistance after five decades of use. 1, 2

First-Line Antibiotic Therapy

Preferred Options (Non-Allergic Patients)

• Penicillin V: 250 mg four times daily (or 500 mg twice daily) in adolescents/adults, or 250 mg two to three times daily in children, for 10 days 1, 2

• Amoxicillin: 50 mg/kg once daily (maximum 1000 mg) or 25 mg/kg twice daily (maximum 500 mg per dose) for 10 days is equally effective and offers superior adherence due to convenient dosing 1, 2, 3

• Intramuscular benzathine penicillin G: Single dose of 600,000 units (<27 kg) or 1,200,000 units (≥27 kg) is preferred when adherence to oral therapy is unlikely 1, 2

Key Evidence: Amoxicillin at 40 mg/kg/day demonstrated significantly better clinical cure (87.9% vs 70.9%) and bacteriologic cure (79.3% vs 54.5%) compared to lower-dose penicillin V, suggesting that inadequate dosing may explain perceived penicillin failures 4. Twice-daily penicillin dosing is as efficacious as more frequent regimens, but once-daily penicillin shows 12 percentage points lower cure rates and should be avoided 5.

Treatment for Penicillin-Allergic Patients

Non-Immediate/Non-Anaphylactic Allergy

• First-generation cephalosporins are the preferred alternative with strong, high-quality evidence 1, 6, 2
  • Cephalexin: 20 mg/kg per dose twice daily (maximum 500 mg per dose) for 10 days 1, 6
  • Cefadroxil: 30 mg/kg once daily (maximum 1 gram) for 10 days 1, 6
  • Cross-reactivity risk with penicillin is less than 3%, making them safe in most penicillin-allergic patients 7

Immediate/Anaphylactic Penicillin Allergy

Avoid all beta-lactams (including cephalosporins) due to up to 10% cross-reactivity risk 6

• Clindamycin (preferred): 7 mg/kg per dose three times daily (maximum 300 mg per dose) for 10 days 1, 6, 2

  • Demonstrates high efficacy even in chronic carriers with only 1% resistance in the United States 6, 2
  • Strong, moderate-quality evidence 1, 6

• Azithromycin: 12 mg/kg once daily (maximum 500 mg) for 5 days 1, 6, 8

  • Only antibiotic requiring just 5 days due to prolonged tissue half-life 6, 2
  • Macrolide resistance is approximately 5-8% in the United States 6, 2

• Clarithromycin: 7.5 mg/kg per dose twice daily (maximum 250 mg per dose) for 10 days 1, 6

Critical Caveat: While cephalosporins show superior bacteriologic cure rates compared to penicillin in meta-analyses (OR 2.29-2.34), these differences are not clinically relevant in high-income countries with low complication rates 1. Macrolides demonstrate clinical efficacy comparable to penicillin but fail to eradicate clarithromycin-resistant isolates (14-19% eradication vs 74-83% for susceptible strains) 9.

Treatment Duration Requirements

• All antibiotics except azithromycin require a full 10-day course to achieve maximal pharyngeal eradication of Group A Streptococcus and prevent acute rheumatic fever 1, 6, 2, 3

• Recent evidence suggests 5-7 day courses may be non-inferior (no difference in recurrence: 9.8% vs 9.5%), but this contradicts established guidelines prioritizing rheumatic fever prevention 10

• In real-world practice, adhere to the 10-day standard given the catastrophic consequences of rheumatic fever, even if rare in developed countries 1, 2

Adjunctive Therapy

• Acetaminophen or NSAIDs can be used for moderate to severe symptoms or high fever 1, 6, 2

• Avoid aspirin in children due to Reye syndrome risk 6, 2

• Corticosteroids are not recommended as adjunctive therapy 1, 6, 2

Special Considerations and Common Pitfalls

When NOT to Treat

• Do not use antibiotics in patients with 0-2 Centor criteria (sudden onset, fever, tonsillar exudates, tender anterior cervical nodes, absence of cough) 1

• Diagnostic testing is not recommended if viral features predominate (cough, rhinorrhea, hoarseness, oral ulcers) 1

Concurrent Infectious Mononucleosis

• Avoid ampicillin and amoxicillin in patients with concurrent mononucleosis due to high risk of severe rash 1, 7

• Use first-generation cephalosporins, clindamycin, or erythromycin instead if streptococcal infection is documented 7

Post-Treatment Follow-Up

• Routine follow-up throat cultures are not recommended for asymptomatic patients who completed therapy 6, 2

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

Recurrent Infections

• Patients with recurrent pharyngitis and positive cultures may be chronic carriers experiencing repeated viral infections 1

• Chronic carriers generally do not require treatment as they are unlikely to spread infection or develop complications 6, 2

• For true recurrent infections, consider clindamycin, amoxicillin-clavulanate, or benzathine penicillin G with rifampin 2

Resistance Concerns

• Group A Streptococcus has shown no resistance to penicillins over five decades 1

• Be aware of local macrolide resistance patterns before prescribing azithromycin or clarithromycin, as resistance varies geographically 6, 2

• Trimethoprim-sulfamethoxazole should never be used due to 50% resistance rates 6