What is the recommended treatment for strep throat in adults?

Treatment of Strep Throat in Adults

For adults with confirmed Group A streptococcal pharyngitis, penicillin V 500 mg twice daily or 250 mg four times daily for 10 days is the first-line treatment, with amoxicillin 500 mg twice daily for 10 days as an equally effective alternative. 1, 2, 3

First-Line Antibiotic Therapy

Penicillin remains the drug of choice due to its proven efficacy, safety, narrow spectrum of activity, and low cost. 1, 4 The recommended dosing is:

• Penicillin V: 500 mg twice daily OR 250 mg four times daily for 10 days 1, 2, 4
• Amoxicillin: 500 mg twice daily for 10 days (equally effective alternative) 2, 3, 5

For patients unlikely to complete a full 10-day oral course, intramuscular benzathine penicillin G 1.2 million units as a single dose is preferred to ensure compliance. 2, 3, 4

Treatment for Penicillin-Allergic Patients

The choice depends on the type of allergic reaction:

For non-immediate (non-anaphylactic) penicillin allergy:

• First-generation cephalosporins (e.g., cephalexin) for 10 days 1, 3, 4

For immediate hypersensitivity or anaphylactic reactions to penicillin:

• Clindamycin 300 mg three times daily for 10 days 1, 2, 4
• Azithromycin 500 mg on day 1, then 250 mg once daily for days 2-5 (total 5 days) 1, 2, 3
• Clarithromycin 250 mg twice daily for 10 days 1, 3

Critical Caveat on Macrolides

Macrolide resistance (azithromycin, clarithromycin) varies geographically, with rates around 5-8% in the United States but higher in some regions. 4, 6 In areas with high clarithromycin resistance, these agents may fail to eradicate Group A streptococci despite clinical improvement. 6 Consider local resistance patterns when selecting macrolides. 7

Treatment Duration

A full 10-day course is required for most antibiotics to achieve maximal pharyngeal eradication of Group A streptococci and prevent acute rheumatic fever. 1, 2, 3

The only exception is azithromycin, which requires only 5 days due to its prolonged tissue half-life. 1, 2, 3

Shorter courses of other antibiotics (3-7 days) have shown small clinical differences favoring the full 10-day treatment, with higher rates of bacteriologic failure. 1

Antibiotics to Avoid

Do not use tetracyclines, sulfonamides, or fluoroquinolones for streptococcal pharyngitis due to high resistance rates and frequent treatment failures. 2, 4

Adjunctive Symptomatic Treatment

• Acetaminophen or NSAIDs for moderate to severe symptoms or high fever 1
• Avoid aspirin in children (though this applies to pediatric patients) 1
• Corticosteroids are not recommended 1

Follow-Up and Special Circumstances

Routine post-treatment throat cultures or rapid antigen tests are not recommended for asymptomatic patients after completing therapy. 1, 2 Testing may be considered only in special circumstances such as:

• Personal or family history of rheumatic fever 1
• Outbreak situations 4
• Worsening symptoms after appropriate antibiotic initiation 7

Do not routinely test or treat asymptomatic household contacts unless special circumstances exist. 1, 4

Common Pitfalls

• Prescribing antibiotics without confirmation: Only 10% of adults with sore throat have streptococcal pharyngitis, yet 60% or more receive antibiotics. 7 Confirm diagnosis with rapid antigen testing or throat culture before treating. 1
• Incomplete treatment courses: Emphasize the importance of completing the full 10-day course to prevent treatment failure and complications. 1
• Using macrolides in high-resistance areas: Be aware of local resistance patterns, as macrolide failure rates can be significant. 4, 6