What is the recommended treatment for a patient with strep throat?

Treatment of Strep Throat

Penicillin or amoxicillin for 10 days is the definitive first-line treatment for strep throat in patients without penicillin allergy. 1, 2, 3

First-Line Treatment for Non-Allergic Patients

• Penicillin V or amoxicillin remains the drug of choice due to proven efficacy, safety, narrow spectrum, low cost, and zero documented resistance in Group A Streptococcus worldwide 1, 2
• Amoxicillin is often preferred in young children due to better palatability of the suspension 2
• The full 10-day course is mandatory to achieve maximal pharyngeal eradication and prevent acute rheumatic fever—shortening by even a few days dramatically increases treatment failure rates 1, 2, 3

Specific Dosing Regimens

Adults and children ≥40 kg:

• Penicillin V: 250 mg four times daily or 500 mg twice daily 2
• Amoxicillin: 500 mg every 12 hours or 250 mg every 8 hours for mild/moderate infections 3

Children <40 kg:

• Amoxicillin: 25 mg/kg/day divided every 12 hours or 20 mg/kg/day divided every 8 hours 3

Treatment for Penicillin-Allergic Patients

The choice of alternative antibiotic depends critically on the type of penicillin allergy 1, 4:

Non-Immediate (Non-Anaphylactic) Penicillin Allergy

First-generation cephalosporins are safe and preferred with only 0.1% cross-reactivity risk in patients with delayed, non-severe reactions 1, 2:

• Cephalexin: 20 mg/kg/dose twice daily (maximum 500 mg/dose) for 10 days 1, 4, 2
• Cefadroxil: 30 mg/kg once daily (maximum 1 gram) for 10 days 1, 4

Immediate/Anaphylactic Penicillin Allergy

All beta-lactams must be avoided due to up to 10% cross-reactivity risk with cephalosporins 1, 2:

Clindamycin is the preferred choice:

• Dosing: 7 mg/kg/dose three times daily (maximum 300 mg/dose) for 10 days 1, 4, 2
• Advantages: Only ~1% resistance rate in the United States, highly effective even in chronic carriers 1
• Evidence quality: Strong, moderate-quality evidence 1

Azithromycin is an acceptable alternative:

• Dosing: 12 mg/kg once daily (maximum 500 mg) for 5 days 1, 4, 5
• Unique feature: Only antibiotic requiring just 5 days due to prolonged tissue half-life 1, 5
• Limitation: 5-8% macrolide resistance in the United States, making clindamycin more reliable 1, 2

Clarithromycin:

• Dosing: 7.5 mg/kg/dose twice daily (maximum 250 mg/dose) for 10 days 1, 4
• Same resistance concerns as azithromycin 1

Critical Treatment Principles

Duration Requirements

• 10 days is essential for all antibiotics except azithromycin to prevent acute rheumatic fever and achieve maximal bacterial eradication 1, 2, 3
• Treatment should continue for at least 48-72 hours beyond symptom resolution 3
• Azithromycin's 5-day course is the only exception due to its unique pharmacokinetics 1, 5

Adjunctive Symptom Management

• Use acetaminophen or NSAIDs (ibuprofen) for moderate to severe symptoms or high fever 1, 2
• Never use aspirin in children due to Reye syndrome risk 1, 2
• Corticosteroids are not recommended as adjunctive therapy 1, 2

Common Pitfalls to Avoid

Antibiotic Selection Errors

• Never use trimethoprim-sulfamethoxazole (Bactrim) for strep throat—50% resistance rate and ineffective against Group A Streptococcus 1, 2
• Do not prescribe cephalosporins to patients with immediate/anaphylactic penicillin reactions due to 10% cross-reactivity risk 1, 2
• Avoid assuming all penicillin-allergic patients cannot receive cephalosporins—only those with immediate/anaphylactic reactions should avoid them 1

Treatment Duration Errors

• Never shorten courses below 10 days (except azithromycin's 5-day regimen)—this dramatically increases treatment failure and rheumatic fever risk 1, 2
• Even though symptoms typically resolve within 3-4 days, full course completion is essential for preventing complications 1

Macrolide Considerations

• Be aware of local macrolide resistance patterns before prescribing azithromycin or clarithromycin—resistance varies geographically 1, 4
• Do not use azithromycin as first-line therapy when penicillin can be used 1

Post-Treatment Management

• Routine follow-up throat cultures are not recommended for asymptomatic patients who completed therapy 1, 2
• Consider follow-up testing only in special circumstances, such as patients with a history of rheumatic fever 1, 2
• Reevaluate patients with worsening symptoms after appropriate antibiotic initiation or symptoms lasting 5 days after treatment start 6

Special Considerations for Recurrent Cases

• Confirm each episode with rapid antigen detection test (RADT) or throat culture before treating 4
• Distinguish between true recurrent infections versus chronic carriage with viral infections—chronic carriers generally do not require treatment 1, 4
• Clindamycin may be particularly effective for recurrent streptococcal pharyngitis due to its ability to eradicate the organism in chronic carriers 1