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 no documented resistance and proven efficacy in preventing acute rheumatic fever. 1, 2

Diagnostic Confirmation Before Treatment

• Test patients with 2 or more Centor criteria (fever, tonsillar exudates, 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 strep infection 1, 2
• Do not test or treat if viral features predominate (cough, rhinorrhea, hoarseness, conjunctivitis, oral ulcers) 1

First-Line Antibiotic Therapy for Non-Allergic Patients

Penicillin V remains the gold standard due to its narrow spectrum, proven efficacy, safety profile, and low cost, with zero documented resistance over five decades. 1, 2

Dosing Regimens:

Adults:

• Penicillin V: 500 mg orally twice daily for 10 days 1, 2
• Alternative: 250 mg four times daily for 10 days 1

Children and adolescents:

• Penicillin V: 250 mg twice or three times daily for 10 days 1, 2
• Amoxicillin: 50 mg/kg once daily (maximum 1000 mg) OR 25 mg/kg twice daily (maximum 500 mg per dose) for 10 days 1, 3

Amoxicillin is equally effective and often preferred in children due to better palatability and once-daily dosing option, which enhances adherence. 1, 2, 4

Intramuscular Option:

• Benzathine penicillin G: Single dose of 600,000 units for patients <27 kg (60 lbs) or 1,200,000 units for patients ≥27 kg when adherence is questionable 1, 2

Treatment for Penicillin-Allergic Patients

Non-Immediate/Non-Anaphylactic Allergy:

First-generation cephalosporins are the preferred alternatives with strong, high-quality evidence and only 0.1% cross-reactivity risk in patients with non-severe, delayed penicillin reactions. 1, 5, 2

• Cephalexin: 20 mg/kg per dose twice daily (maximum 500 mg per dose) for 10 days in children; 500 mg twice daily for 10 days in adults 1, 5
• Cefadroxil: 30 mg/kg once daily (maximum 1 gram) for 10 days 1, 5

Immediate/Anaphylactic Allergy:

Clindamycin is the preferred choice with approximately 1% resistance rate in the United States and high efficacy even in chronic carriers. 1, 5, 2

• Clindamycin: 7 mg/kg per dose three times daily (maximum 300 mg per dose) for 10 days 1, 5

Macrolide Alternatives (with resistance concerns):

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

Macrolide resistance among Group A Streptococcus ranges from 5-8% in the United States but varies geographically, making clindamycin or first-generation cephalosporins preferred in areas with high resistance. 1, 5, 6

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, 2

• Azithromycin requires only 5 days due to its prolonged tissue half-life and unique pharmacokinetics 1, 5, 2
• Therapy can be safely postponed up to 9 days after symptom onset and still prevent acute rheumatic fever 5
• Shortening the course by even a few days results in appreciable increases in treatment failure rates 5

Adjunctive Symptomatic Treatment

• Acetaminophen or NSAIDs (ibuprofen) can be used for moderate to severe symptoms or high fever 1, 5
• Aspirin must be avoided in children due to risk of Reye syndrome 1, 5
• Corticosteroids are not recommended as adjunctive therapy 1, 5

Common Pitfalls to Avoid

• Do not use cephalosporins in patients with immediate/anaphylactic penicillin reactions due to up to 10% cross-reactivity risk 1, 5, 2
• Do not prescribe shorter courses than recommended (except azithromycin's 5-day regimen) as this increases treatment failure and rheumatic fever risk 1, 5, 2
• Do not use trimethoprim-sulfamethoxazole or tetracyclines as they do not eradicate Group A Streptococcus 1, 5
• Check local macrolide resistance patterns before prescribing azithromycin or clarithromycin, as resistance varies geographically 5, 2, 6
• Do not use broad-spectrum cephalosporins (cefdinir, cefpodoxime) when narrow-spectrum first-generation agents are appropriate, as they are more expensive and select for resistant flora 1, 5
• Avoid ampicillin and amoxicillin if concurrent infectious mononucleosis is suspected, as this causes a characteristic rash in up to 90% of cases 7

Post-Treatment Considerations

• Routine follow-up throat cultures are not recommended for asymptomatic patients who have completed therapy 1, 7, 2
• Patients become non-contagious after 24 hours of appropriate antibiotic therapy 7
• Follow-up testing may be considered only in special circumstances, such as patients with a history of rheumatic fever 5, 2

Special Clinical Situations

Recurrent pharyngitis: Distinguish between true recurrent infections versus chronic carrier state with viral infections; chronic carriers generally do not require antimicrobial therapy as they are unlikely to spread infection and are at little risk for complications 1, 5, 2

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