What is the recommended treatment for strep throat in an adult?

Treatment of Strep Throat in Adults

Penicillin V 500 mg twice daily or 250 mg four times daily for 10 days is the recommended first-line treatment for strep throat in adults, based on proven efficacy, safety, narrow spectrum, and low cost. 1, 2

First-Line Treatment: Penicillin or Amoxicillin

• Penicillin V remains the drug of choice because no penicillin resistance has been documented in Group A Streptococcus anywhere in the world, and it offers the narrowest antimicrobial spectrum with the lowest cost 1, 2

• Amoxicillin 500 mg twice daily for 10 days is an equally effective alternative to penicillin V, often preferred due to better palatability and equivalent efficacy 2, 3

• Intramuscular benzathine penicillin G 1.2 million units as a single dose should be used for patients unlikely to complete a full 10-day oral course, ensuring compliance and preventing treatment failure 1, 2

Critical Treatment Duration

• A full 10-day course is mandatory to achieve maximal pharyngeal eradication of Group A Streptococcus and prevent acute rheumatic fever, regardless of symptom resolution 1, 2, 3

• Therapy can be safely postponed up to 9 days after symptom onset and still prevent acute rheumatic fever 1, 3

• Shortening the course below 10 days results in appreciable increases in treatment failure rates and risk of complications 2, 3

Treatment for Penicillin-Allergic Patients

Non-Immediate (Non-Anaphylactic) Penicillin Allergy

First-generation cephalosporins are the preferred alternatives for patients without immediate hypersensitivity reactions 1, 2, 4:

• Cephalexin 500 mg twice daily for 10 days is the recommended regimen, with only 0.1% cross-reactivity risk in patients with non-severe, delayed penicillin reactions 2, 4

• Cefadroxil 1 gram once daily for 10 days is an acceptable alternative 2, 4

Immediate/Anaphylactic Penicillin Allergy

All beta-lactam antibiotics must be avoided due to up to 10% cross-reactivity risk with cephalosporins in patients with immediate hypersensitivity 1, 4:

• Clindamycin 300 mg three times daily for 10 days is the preferred choice, with approximately 1% resistance rate among Group A Streptococcus in the United States and high efficacy even in chronic carriers 1, 2, 4

• Azithromycin 500 mg once daily for 5 days is an acceptable alternative, though macrolide resistance is 5-8% in the United States and varies geographically 1, 2, 5

• Clarithromycin 250 mg twice daily for 10 days is also acceptable, with similar resistance concerns as azithromycin 1, 2, 4

Important Resistance and Efficacy Considerations

• Macrolide resistance among Group A Streptococcus ranges from 5-8% in most areas of the United States, making clindamycin more reliable than azithromycin or clarithromycin in areas with high resistance 1, 2, 4

• Clindamycin resistance remains very low at approximately 1% in the United States 1, 2

• One study suggests that 10 days of clarithromycin may be more effective in eradicating Group A Streptococcus pharyngitis than 5 days of azithromycin 1

Adjunctive Symptomatic Treatment

• Acetaminophen or NSAIDs (such as ibuprofen) should be considered for moderate to severe symptoms or control of high fever, with strong evidence for reducing pain and inflammation 1, 2, 3

• Aspirin must be avoided in children due to the risk of Reye syndrome 1, 2, 3

• Corticosteroids are not recommended as adjunctive therapy, despite minimal pain reduction (approximately 5 hours), due to potential adverse effects and the self-limited nature of the illness 1, 2, 3

Common Pitfalls to Avoid

• Do not use tetracyclines, sulfonamides, or trimethoprim-sulfamethoxazole for strep throat due to high resistance rates and ineffectiveness for Group A Streptococcus eradication 1, 2, 3

• Do not prescribe broad-spectrum cephalosporins when narrow-spectrum agents are appropriate, as they are more expensive and more likely to select for antibiotic-resistant flora 1, 3

• Do not use cephalosporins in patients with immediate hypersensitivity to penicillin (anaphylaxis, angioedema, or immediate urticaria) due to the 10% cross-reactivity risk 1, 4

• Do not prescribe azithromycin as first-line therapy when penicillin or amoxicillin can be used, as this unnecessarily broadens the antibiotic spectrum and contributes to resistance 2, 3

• Do not shorten the treatment course below 10 days (except for azithromycin's 5-day regimen) despite clinical improvement, as this increases treatment failure rates and risk of acute rheumatic fever 2, 3

Follow-Up and Special Circumstances

• Routine post-treatment throat cultures or rapid antigen detection tests are not recommended for asymptomatic patients who have completed therapy 1, 2

• Follow-up testing should only be considered in special circumstances, such as patients with a history of rheumatic fever 1, 2

• Patients with worsening symptoms after appropriate antibiotic initiation or with symptoms lasting 5 days after the start of treatment should be reevaluated 6