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 due to proven efficacy, narrow spectrum, complete absence of resistance, safety profile, and low cost. 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 initiating 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
• Diagnostic testing is not recommended if clinical features strongly suggest viral etiology (cough, rhinorrhea, hoarseness, oral ulcers) 1

First-Line Antibiotic Regimens for Non-Allergic Patients

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, 2

Amoxicillin (oral) - equally effective and more palatable:

• Adults and children ≥40 kg: 500 mg twice daily for 10 days 1, 3
• Children <40 kg: 25 mg/kg/day divided twice daily (or 50 mg/kg once daily, maximum 1000 mg) for 10 days 1, 3
• Amoxicillin is often preferred in young children due to better taste acceptance 1, 4

Intramuscular benzathine penicillin G:

• <27 kg (60 lb): 600,000 units as single dose 1
• ≥27 kg: 1,200,000 units as single dose 1
• Reserved for patients with questionable adherence to oral therapy 1, 2

Treatment for Penicillin-Allergic Patients

Non-Immediate/Non-Anaphylactic Penicillin Allergy

First-generation cephalosporins are the preferred alternatives (cross-reactivity risk only 0.1% in non-severe reactions) 5, 2:

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

Immediate/Anaphylactic Penicillin Allergy

Avoid all beta-lactams including cephalosporins due to up to 10% cross-reactivity risk 1, 5, 2

Clindamycin is the preferred choice:

• 7 mg/kg per dose three times daily (maximum 300 mg per dose) for 10 days 1, 5
• Approximately 1% resistance rate in the United States 1, 5, 2
• Particularly effective for chronic carriers and difficult-to-eradicate infections 5, 6

Macrolides are acceptable alternatives but have higher resistance:

• 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
• Macrolide resistance is approximately 5-8% in the United States and varies geographically 1, 5, 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, 2. Azithromycin requires only 5 days due to its prolonged tissue half-life and unique pharmacokinetics 1, 5, 2.

Adjunctive Symptomatic Treatment

• Acetaminophen or NSAIDs (ibuprofen) should be considered for moderate to severe symptoms or high fever 1, 5
• Aspirin must be avoided in children due to risk of Reye syndrome 1, 5, 2
• Corticosteroids are not recommended as adjunctive therapy 1, 5, 2

Special Clinical Situations

Concurrent infectious mononucleosis:

• Avoid ampicillin and amoxicillin due to high risk of severe rash (up to 90%) 6
• Use first-generation cephalosporin (cephalexin or cefadroxil), clindamycin, or erythromycin if antibiotic treatment is indicated for documented Group A streptococcal infection 6

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 1, 5
• For documented recurrent infections with treatment failures, consider clindamycin or amoxicillin-clavulanate 2

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

Common Pitfalls to Avoid

• Do not prescribe shorter courses than recommended (except azithromycin's 5-day regimen) as this increases treatment failure rates and risk of acute rheumatic fever 1, 5, 2
• Do not use cephalosporins in patients with immediate/anaphylactic penicillin reactions due to 10% cross-reactivity risk 1, 5, 2
• Do not use tetracyclines due to high prevalence of resistant strains 1
• Do not use sulfonamides or trimethoprim-sulfamethoxazole as they do not eradicate Group A Streptococcus 1, 5
• Do not use older fluoroquinolones (ciprofloxacin) as they have limited activity against Group A Streptococcus 1
• Check local macrolide resistance patterns before prescribing azithromycin or clarithromycin, as resistance varies geographically and can lead to treatment failure 5, 2
• Do not routinely perform follow-up throat cultures in asymptomatic patients who have completed therapy 1, 6, 2

When to Reevaluate

Patients with worsening symptoms after appropriate antibiotic initiation or with symptoms lasting 5 days after the start of treatment should be reevaluated 7. Patients become non-contagious after 24 hours of appropriate antibiotic therapy 6.