What is the recommended antibiotic for strep throat?

Recommended Antibiotic for Strep Throat

Penicillin or amoxicillin is the first-line antibiotic treatment for strep throat due to their narrow spectrum of activity, few adverse effects, modest cost, and continued effectiveness against Group A Streptococcus. 1

First-Line Treatment Options (For Patients Without Penicillin Allergy)

• Oral Penicillin V:

  • Children: 250 mg two or three times daily for 10 days
  • Adolescents and adults: 250 mg four times daily or 500 mg twice daily for 10 days 1

• Oral Amoxicillin:

  • 50 mg/kg once daily (maximum = 1,000 mg) or
  • 25 mg/kg twice daily (maximum = 500 mg) for 10 days 1
  • Often preferred for young children due to better taste acceptance 1

• Intramuscular Benzathine Penicillin G (single dose):

  • <27 kg: 600,000 U
  • ≥27 kg: 1,200,000 U 1
  • Preferred when compliance with oral therapy is a concern 2

Alternative Options (For Patients With Penicillin Allergy)

• First-generation Cephalosporins (for non-immediate hypersensitivity to penicillin):

  • Cephalexin: 20 mg/kg/dose twice daily (maximum = 500 mg/dose) for 10 days
  • Cefadroxil: 30 mg/kg once daily (maximum = 1 g) for 10 days 1

• Clindamycin: 7 mg/kg/dose three times daily (maximum = 300 mg/dose) for 10 days 1

• Macrolides (note: resistance is well-known and varies geographically):

  • Azithromycin: 12 mg/kg once daily (maximum = 500 mg) for 5 days
  • Clarithromycin: 7.5 mg/kg/dose twice daily (maximum = 250 mg/dose) for 10 days 1

Important Clinical Considerations

• Full 10-day course is critical: Even though symptoms typically resolve within 24-48 hours of starting antibiotics, completing the full course is essential to prevent rheumatic fever 2

• Macrolide resistance: Group A Streptococcus resistance to macrolides (azithromycin, clarithromycin) varies by region and time period. These should only be used when penicillins and cephalosporins cannot be used 1, 3

• Prevention of rheumatic fever: Penicillin and amoxicillin are the only antibiotics with proven efficacy in preventing rheumatic fever. FDA labeling for azithromycin specifically states: "Data establishing efficacy of azithromycin in subsequent prevention of rheumatic fever are not available" 3

• Treatment efficacy: Studies have shown that 10-day courses of clarithromycin are more effective than 5-day courses of azithromycin in eradicating Group A Streptococcus (91% vs 82%) 4

• Penicillin failure rates: While historically very low (2-10%), penicillin failure rates have increased to approximately 30% in some studies, primarily due to poor compliance with the 10-day regimen 5

Special Situations

• Chronic carriers: Different antibiotic regimens are recommended for chronic carriers of Group A Streptococcus, including clindamycin, penicillin with rifampin, or amoxicillin/clavulanate 1

• Adjunctive therapy: Analgesics or antipyretics (acetaminophen, NSAIDs) can be used for symptom relief. Aspirin should be avoided in children, and corticosteroids are not recommended 1

Remember that proper diagnosis through rapid antigen detection testing or throat culture is essential before initiating antibiotic therapy for suspected strep throat to avoid unnecessary antibiotic use 1.