Treatment of Strep Throat
Penicillin or amoxicillin for 10 days is the recommended first-line treatment for strep throat, with amoxicillin preferred due to better compliance with twice-daily dosing and proven superior efficacy at appropriate doses. 1
First-Line Treatment for Patients Without Penicillin Allergy
Penicillin and amoxicillin remain the drugs of choice because of their narrow spectrum of activity, proven efficacy in preventing acute rheumatic fever, safety profile, and low cost. 1
Recommended Dosing Regimens:
Amoxicillin (preferred oral option): 50 mg/kg once daily (maximum 1,000 mg) for 10 days, or alternatively 25 mg/kg twice daily (maximum 500 mg per dose) for 10 days 1
Penicillin V (oral): Children: 250 mg two or three times daily; Adolescents and adults: 250 mg four times daily or 500 mg twice daily for 10 days 1
Penicillin G benzathine (intramuscular): Single dose of 600,000 units for patients <60 lb (27 kg) or 1,200,000 units for patients ≥60 lb 1
- Preferred when compliance with oral therapy is unlikely 1
Treatment for Patients With Penicillin Allergy
The choice of alternative antibiotic depends on the type of allergic reaction:
For Non-Anaphylactic Penicillin Allergy:
For Anaphylactic Penicillin Allergy:
Clindamycin: 7 mg/kg per dose three times daily (maximum 300 mg per dose) for 10 days 1, 5
Azithromycin: 12 mg/kg once daily (maximum 500 mg) for 5 days 1, 5
Clarithromycin: 7.5 mg/kg per dose twice daily (maximum 250 mg per dose) for 10 days 1, 5
- Same resistance concerns as azithromycin 1
Duration of Therapy
A full 10-day course is required for penicillin, amoxicillin, cephalosporins, clindamycin, and clarithromycin to achieve maximal pharyngeal eradication of group A streptococci. 1 The exception is azithromycin, which is given for 5 days. 1
Shorter courses with newer agents cannot be recommended despite some studies suggesting comparable cure rates, as definitive comprehensive studies are not available, these agents have broader spectrums than penicillin, and most are more expensive. 1
Adjunctive Symptomatic Treatment
- Analgesics/antipyretics: Acetaminophen or NSAIDs should be considered for moderate to severe symptoms or high fever 1, 5
- Aspirin should be avoided in children due to risk of Reye syndrome 1, 5
- Corticosteroids are not recommended for routine treatment 1, 5
Management of Treatment Failures and Recurrent Cases
Distinguishing True Recurrence from Chronic Carriage:
Patients with recurrent pharyngitis and positive cultures may be chronic carriers experiencing repeated viral infections rather than true recurrent streptococcal infections. 1, 5
When to Treat Chronic Carriers:
Antibiotics are not generally recommended for chronic carriers but may be considered in specific situations: 1
- During community outbreaks of acute rheumatic fever, acute poststreptococcal glomerulonephritis, or invasive group A streptococcal infection
- During outbreaks in closed or partially closed communities
- Family or personal history of acute rheumatic fever
- Excessive anxiety about group A streptococcal infections
- When tonsillectomy is being considered solely because of carrier state
Treatment Regimens for Chronic Carriers:
- Clindamycin: 20-30 mg/kg/day in three doses (maximum 300 mg per dose) for 10 days 1
- Amoxicillin/clavulanate: 40 mg amoxicillin/kg/day in three doses (maximum 2,000 mg amoxicillin per day) for 10 days 1
- Penicillin plus rifampin: Penicillin V 50 mg/kg/day in four doses for 10 days (maximum 2,000 mg/day) plus rifampin 20 mg/kg/day in one dose for last four days (maximum 600 mg/day) 1
Common Pitfalls to Avoid
- Inadequate dosing of penicillin: The perception that penicillin is declining in effectiveness may be due to inadequate dosing rather than true resistance 3
- Using once-daily penicillin: This is associated with decreased efficacy and should not be used 4
- Prescribing macrolides without considering local resistance patterns: Geographic variation in resistance is well-known 1, 5, 7
- Routine follow-up testing: Post-treatment throat cultures or rapid antigen tests are not recommended routinely 1
- Testing or treating asymptomatic household contacts: This is not routinely recommended 1
- Overdiagnosis of viral pharyngitis as bacterial: Testing is not recommended when clinical features strongly suggest viral etiology (cough, rhinorrhea, hoarseness, oral ulcers) 1, 5
- Testing children under 3 years old: Streptococcal pharyngitis is uncommon in this age group unless risk factors are present (e.g., older sibling with infection) 1
Why Penicillin/Amoxicillin Remains Superior
Despite bacteriologic failure rates increasing from 2-10% in the 1970s to approximately 30% currently, penicillin remains the treatment of choice. 8 The primary cause of treatment failure is lack of compliance with the 10-day regimen, not true antibiotic resistance. 8 Other contributing factors include reexposure to infected contacts, copathogenicity with protective bacteria, and antibiotic-associated eradication of normal pharyngeal flora. 8
Group A streptococci have never developed resistance to penicillin, making it the gold standard when compliance can be ensured. 1 Amoxicillin offers the advantage of better compliance with less frequent dosing while maintaining the narrow spectrum and proven efficacy in preventing acute rheumatic fever—the most critical outcome in treating strep throat. 1