What is the recommended treatment for strep throat?

Treatment of Strep Throat

Penicillin or amoxicillin for 10 days is the recommended first-line treatment for strep throat, with penicillin V 250 mg four times daily (or 500 mg twice daily) or amoxicillin 50 mg/kg once daily (maximum 1000 mg) being the drugs of choice due to their narrow spectrum, proven efficacy, safety, and low cost. 1, 2

First-Line Treatment Regimen

For patients without penicillin allergy:

• Penicillin V is the preferred first-line agent with two dosing options: 250 mg four times daily OR 500 mg twice daily for 10 days in adolescents and adults 1, 2
• Amoxicillin 50 mg/kg once daily (maximum 1000 mg) for 10 days is equally effective and often preferred in children due to better palatability and once-daily dosing 1, 2, 3
• Intramuscular benzathine penicillin G as a single dose (600,000 units if <27 kg; 1,200,000 units if ≥27 kg) ensures compliance when adherence to oral therapy is uncertain 1, 2

Critical Treatment Duration

• A full 10-day course is essential for all antibiotics except azithromycin to achieve maximal pharyngeal eradication of Group A Streptococcus and prevent acute rheumatic fever 1, 2
• Shortening the course by even a few days results in appreciable increases in treatment failure rates and risk of rheumatic fever 4, 2
• Azithromycin is the only exception, requiring only 5 days due to its prolonged tissue half-life 1, 4

Treatment for Penicillin-Allergic Patients

The type of penicillin allergy determines the safest alternative:

Non-Immediate (Non-Anaphylactic) Penicillin Allergy

• First-generation cephalosporins are the preferred alternatives with strong, high-quality evidence 1, 4, 2
• Cephalexin 20 mg/kg per dose twice daily (maximum 500 mg per dose) for 10 days 1, 4
• Cefadroxil 30 mg/kg once daily (maximum 1 gram) for 10 days 1, 4
• Cross-reactivity risk is only 0.1% in patients with non-severe, delayed penicillin reactions 4

Immediate/Anaphylactic Penicillin Allergy

Avoid all beta-lactam antibiotics (including cephalosporins) due to up to 10% cross-reactivity risk 1, 4

• Clindamycin is the preferred choice with strong, moderate-quality evidence: 7 mg/kg per dose three times daily (maximum 300 mg per dose) for 10 days 1, 4, 2
• Clindamycin has approximately 1% resistance rate among Group A Streptococcus in the United States 4, 2
• Clindamycin demonstrates high efficacy in eradicating streptococci, even in chronic carriers 4

Alternative macrolides (if clindamycin cannot be used):

• Azithromycin 12 mg/kg once daily (maximum 500 mg) for 5 days 1, 4
• Clarithromycin 7.5 mg/kg per dose twice daily (maximum 250 mg per dose) for 10 days 1, 4
• Important caveat: Macrolide resistance among Group A Streptococcus is approximately 5-8% in the United States and varies geographically 4, 5, 6
• Azithromycin should not be relied upon as first-line therapy and should be reserved for patients with documented penicillin allergy who cannot tolerate other alternatives 4, 5

Adjunctive Symptomatic Treatment

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

Common Pitfalls to Avoid

• Do not prescribe shorter courses than recommended (except for azithromycin's 5-day regimen) as this leads to treatment failure and increased risk of acute rheumatic fever 4, 2
• Do not use cephalosporins in patients with immediate/anaphylactic penicillin reactions due to the 10% cross-reactivity risk 1, 4
• Do not assume all penicillin-allergic patients cannot receive cephalosporins - only those with immediate/anaphylactic reactions should avoid them 4
• Do not use azithromycin as first-line therapy - it should only be used when penicillin and preferred alternatives cannot be used 4
• Do not prescribe azithromycin without considering local resistance patterns - macrolide resistance varies geographically and can lead to treatment failure 4, 5, 6
• Do not use broad-spectrum cephalosporins when narrow-spectrum first-generation agents are appropriate, as they are more expensive and more likely to select for antibiotic-resistant flora 4

Special Considerations

• Patients become non-contagious after 24 hours of appropriate antibiotic therapy 7
• Routine follow-up throat cultures or rapid antigen detection tests are not recommended for asymptomatic patients who have completed therapy 1, 7
• Testing of asymptomatic household contacts is not routinely recommended 1
• Patients with recurrent streptococcal pharyngitis may be experiencing either multiple true infections or may be chronic carriers experiencing viral infections 1
• Chronic carriers generally do not require antimicrobial therapy, as they are unlikely to spread GAS pharyngitis and are at little risk for complications 4

When to Avoid Aminopenicillins

• Avoid ampicillin and amoxicillin in patients with concurrent infectious mononucleosis, as these cause a characteristic maculopapular rash in 80-100% of patients with Epstein-Barr virus infection 7
• Use a first-generation cephalosporin, clindamycin, or erythromycin instead if antibiotic treatment is indicated for documented Group A streptococcal infection in this setting 7