What is the recommended treatment for strep throat?

Treatment of Strep Throat

Penicillin or amoxicillin for 10 days is the definitive first-line treatment for strep throat, with amoxicillin often preferred due to better palatability and once-daily dosing options. 1, 2

Diagnostic Confirmation Before Treatment

• Test patients with 2 or more Centor criteria (fever, tonsillar exudate, tender anterior cervical lymphadenopathy, absence of cough) using rapid antigen detection test (RADT) or throat culture before prescribing antibiotics 1, 2
• Children under 3 years generally do not require testing unless specific risk factors exist, such as an older sibling with the illness 1, 2
• In children and adolescents with negative RADT, follow up with throat culture to confirm the diagnosis 1, 3

First-Line Antibiotic Therapy

Penicillin V (Oral)

• Adults: 500 mg twice daily for 10 days 1, 2
• Children: 250 mg twice daily or three times daily for 10 days 1
• Penicillin remains the gold standard due to proven efficacy, narrow spectrum, safety, and low cost, with no documented resistance ever reported 1

Amoxicillin (Oral) - Equally Effective Alternative

• Adults and children ≥40 kg: 500 mg twice daily for 10 days 1, 2, 4
• Children <40 kg: 25 mg/kg/day divided twice daily (or 50 mg/kg once daily, maximum 1000 mg) for 10 days 1, 4
• Amoxicillin is often preferred over penicillin V in young children due to better taste acceptance and availability as suspension 1
• Once-daily amoxicillin (50 mg/kg, maximum 1000 mg) has been shown to be as effective as twice-daily dosing and may enhance adherence 1, 5, 6

Intramuscular Benzathine Penicillin G

• <27 kg (60 lb): 600,000 units as single dose 1
• ≥27 kg (60 lb): 1,200,000 units as single dose 1
• Preferred when adherence to oral therapy is questionable 1, 2

Treatment for Penicillin-Allergic Patients

Non-Immediate (Non-Anaphylactic) Penicillin Allergy

First-generation cephalosporins are the preferred alternatives with strong, high-quality evidence: 1, 7, 2

• Cephalexin: 20 mg/kg per dose twice daily (maximum 500 mg per dose) for 10 days 1, 7
• Cefadroxil: 30 mg/kg once daily (maximum 1 gram) for 10 days 1, 7
• Cross-reactivity risk with penicillin is only 0.1% in patients with non-severe, delayed reactions 7

Immediate/Anaphylactic Penicillin Allergy

Avoid all beta-lactam antibiotics (including cephalosporins) due to up to 10% cross-reactivity risk: 1, 7, 2

Clindamycin is the preferred choice:

• Dosage: 7 mg/kg per dose three times daily (maximum 300 mg per dose) for 10 days 1, 7, 2
• Approximately 1% resistance rate among Group A Streptococcus in the United States 1, 7
• Particularly effective for difficult-to-eradicate infections and chronic carriers 7, 8

Macrolides are acceptable alternatives but have higher resistance rates:

• Azithromycin: 12 mg/kg once daily (maximum 500 mg) for 5 days 1, 7
• Clarithromycin: 7.5 mg/kg per dose twice daily (maximum 250 mg per dose) for 10 days 1, 7
• Macrolide resistance is approximately 5-8% in the United States but varies geographically 1, 7, 3
• Check local resistance patterns before prescribing 7, 2

Critical Treatment Duration Requirements

• A full 10-day course is mandatory for all antibiotics except azithromycin to achieve maximal pharyngeal eradication of Group A Streptococcus and prevent acute rheumatic fever 1, 7, 2
• Azithromycin requires only 5 days due to its prolonged tissue half-life and unique pharmacokinetics 1, 7, 2
• Treatment should continue for at least 48-72 hours beyond symptom resolution 4
• Shortening the course by even a few days results in appreciable increases in treatment failure rates 7, 2

Adjunctive Symptomatic Therapy

• Acetaminophen or NSAIDs (such as ibuprofen) should be considered for moderate to severe symptoms or high fever 1, 7
• Aspirin must be avoided in children due to risk of Reye syndrome 1, 7
• Corticosteroids are not recommended as adjunctive therapy 1, 7

Common Pitfalls to Avoid

• Do not prescribe antibiotics without diagnostic confirmation - only 10% of adults with sore throat have strep pharyngitis, yet 60% or more are prescribed antibiotics 3
• Do not use cephalosporins in patients with immediate/anaphylactic penicillin reactions due to 10% cross-reactivity risk 1, 7, 2
• Do not shorten treatment courses below 10 days (except azithromycin's 5-day regimen) as this increases treatment failure and acute rheumatic fever risk 1, 7, 2
• Do not use tetracyclines, sulfonamides, trimethoprim-sulfamethoxazole, or older fluoroquinolones - these are ineffective against Group A Streptococcus 1
• Do not use broad-spectrum cephalosporins (cefdinir, cefpodoxime, cefixime) when narrow-spectrum agents are appropriate - they are more expensive and select for resistant flora 1, 7
• Do not routinely perform post-treatment throat cultures in asymptomatic patients who have completed therapy 1, 8, 2

Special Clinical Situations

Recurrent Pharyngitis

• Distinguish between true recurrent infections versus chronic carrier experiencing viral infections 1, 2
• Chronic carriers generally do not require treatment as they are unlikely to spread infection or develop complications 7, 2
• For documented recurrent infections with treatment failures, clindamycin may be particularly effective 7, 2

Concurrent Infectious Mononucleosis

• Avoid ampicillin and amoxicillin in patients with concurrent mononucleosis due to high risk of severe rash 8
• Use first-generation cephalosporin, clindamycin, or erythromycin if antibiotic treatment is indicated for documented Group A Streptococcal infection 8

Pregnancy

• Penicillin and amoxicillin remain first-line with proven safety 2
• For penicillin-allergic pregnant patients, use cephalexin/cefadroxil for non-anaphylactic allergy or clindamycin for anaphylactic allergy 2

When to Reevaluate

• Patients with worsening symptoms after appropriate antibiotic initiation should be reevaluated 3
• Patients with symptoms lasting 5 days after the start of treatment require reassessment 3
• Patients become non-contagious after 24 hours of appropriate antibiotic therapy 8