What is the treatment for strep throat?

Treatment for Strep Throat

Penicillin or amoxicillin is the first-line treatment for strep throat, typically administered for 10 days to achieve maximal pharyngeal eradication of group A streptococci. 1

First-Line Treatment Options

For Patients Without Penicillin Allergy:

• Oral penicillin V for 10 days:
  • Children: 250 mg two or three times daily 1
  • Adolescents and adults: 250 mg four times daily or 500 mg twice daily 1
• Amoxicillin for 10 days:
  • 50 mg/kg once daily (maximum 1,000 mg) or 25 mg/kg twice daily (maximum 500 mg per dose) 1
  • Often used in place of penicillin V in young children due to better taste acceptance 1
• Intramuscular benzathine penicillin G (single dose):
  • <60 lb (27 kg): 600,000 units 1
  • ≥60 lb (27 kg): 1,200,000 units 1
  • Preferred for patients unlikely to complete a full 10-day course of oral therapy 1, 2

For Patients With Penicillin Allergy:

• First-generation cephalosporins (if no immediate hypersensitivity to β-lactams) for 10 days:
  • Cephalexin: 20 mg/kg twice daily (maximum 500 mg per dose) 1
  • Cefadroxil: 30 mg/kg once daily (maximum 1 g) 1
• Macrolides for penicillin-allergic patients:
  • Erythromycin for 10 days 1
  • Clarithromycin: 7.5 mg/kg twice daily (maximum 250 mg per dose) for 10 days 1
  • Azithromycin: 12 mg/kg once daily (maximum 500 mg) for 5 days 1
• Clindamycin: 7 mg/kg three times daily (maximum 300 mg per dose) for 10 days 1

Adjunctive Therapy

• Acetaminophen or NSAIDs are recommended for relief of acute sore throat symptoms, fever, and pain 1
• Aspirin should be avoided in children due to the risk of Reye syndrome 1
• Corticosteroids are not routinely recommended but may be considered in adult patients with more severe presentations (3-4 Centor criteria) 1

Treatment Duration

• A full 10-day course of antibiotic therapy is recommended for most oral antibiotics to achieve maximal pharyngeal eradication of group A streptococci 1, 2
• While some studies suggest shorter courses (5-7 days) may be effective 3, definitive results from comprehensive studies are not available, and the standard 10-day course remains recommended 1
• Azithromycin is an exception, given for 5 days due to its longer half-life 1

Important Considerations

• Penicillin remains the treatment of choice due to its proven efficacy, safety, narrow spectrum, and low cost 1, 2
• Group A streptococci have not developed resistance to penicillin over at least five decades 1
• Tetracyclines, sulfonamides, and trimethoprim-sulfamethoxazole should not be used for strep throat due to resistance or ineffectiveness 1
• Older fluoroquinolones have limited activity against group A streptococci and should not be used 1
• Patients are generally considered non-contagious after 24 hours of appropriate antibiotic therapy 2

Treatment Failures and Recurrences

• A small percentage of patients may have recurrences of acute pharyngitis with positive strep tests shortly after completing antibiotics 2
• Recurrences may be treated with the same antimicrobial agent used initially 2
• If compliance with oral therapy is questionable, intramuscular benzathine penicillin G should be considered 2
• For multiple recurrences, alternative antibiotics such as clindamycin or amoxicillin/clavulanate may be beneficial due to their higher rates of pharyngeal eradication 2

For Strep-Negative Pharyngitis

• Withhold or discontinue antimicrobial therapy for patients with negative strep tests 4
• Provide symptomatic therapy only, as most cases are viral in nature and self-limiting 4

Pitfalls and Caveats

• Compliance with the full 10-day course is essential to prevent treatment failure 5
• Failure to complete the full course may increase the risk of rheumatic fever and other complications 6
• Skipping doses or not completing the full course may decrease treatment effectiveness and increase antibiotic resistance 6
• Macrolide resistance rates among pharyngeal isolates in the United States are around 5-8%, which may affect treatment success with these agents 1
• Ten days of clarithromycin may be more effective in eradicating group A streptococci than 5 days of azithromycin (91% vs. 82%) 7