What is the first line treatment for strep throat?

First-Line Treatment for Strep Throat

Penicillin V remains the first-line treatment of choice for strep throat (group A streptococcal pharyngitis) due to its proven efficacy, safety, narrow spectrum, and low cost. 1

Treatment Algorithm

First-Line Options:

• Oral Penicillin V:

  • Children: 250 mg twice or three times daily for 10 days
  • Adolescents and adults: 250 mg three or four times daily OR 500 mg twice daily for 10 days 1

• Amoxicillin (alternative, especially for younger children due to better taste):

  • 500 mg three times daily for 10 days (adults)
  • Age-appropriate dosing for children 1, 2

• Intramuscular Benzathine Penicillin G:

  • 1.2 million units as a single dose
  • Preferred for patients unlikely to complete the full 10-day oral course 1

For Penicillin-Allergic Patients:

• Erythromycin:

  • Erythromycin estolate: 20-40 mg/kg/day in 2-3 divided doses for 10 days
  • Erythromycin ethyl succinate: 40 mg/kg/day in 2-3 divided doses for 10 days 1

• First or second-generation cephalosporins (if no immediate hypersensitivity to β-lactams) 1

• Clindamycin: For patients with severe penicillin allergy 1

Evidence Supporting Penicillin as First-Line Treatment

Penicillin has remained the treatment of choice for streptococcal pharyngitis for over five decades due to several important factors:

1. No resistance development: Group A streptococci have not developed resistance to penicillin over at least five decades 1

2. Proven efficacy: Penicillin effectively eradicates the organism from the pharynx in most cases 1

3. Safety profile: Long history of safe use with minimal side effects 1

4. Narrow spectrum: Minimizes disruption to normal flora and reduces risk of antimicrobial resistance 1

5. Cost-effectiveness: Most affordable option compared to newer antibiotics 1

Treatment Duration Considerations

The standard 10-day course of oral antibiotics is still recommended to achieve maximal pharyngeal eradication of group A streptococci. Although some newer agents (azithromycin, cefuroxime, cefixime, cefpodoxime) have been studied for shorter courses (≤5 days), definitive results from comprehensive studies are not available to recommend these shorter courses 1.

Important Clinical Considerations

• Complete the full course: Emphasize the importance of completing the entire 10-day course, even if symptoms resolve earlier, to prevent rheumatic fever 1

• Symptom management: NSAIDs are more effective than acetaminophen for fever and pain; medicated throat lozenges used every two hours can also provide symptomatic relief 2

• Treatment failures: A small percentage of patients may have recurrent episodes. These can be treated with the same agents, but if compliance is questionable, intramuscular benzathine penicillin G should be considered 1

• Chronic carriers: Patients who continue to test positive for group A streptococci after appropriate treatment are often chronic carriers and generally do not require additional treatment 3

Common Pitfalls to Avoid

1. Undertreatment: Not completing the full 10-day course increases the risk of rheumatic fever and treatment failure

2. Overtreatment: Using broader-spectrum antibiotics when not needed contributes to antimicrobial resistance

3. Misdiagnosis: Relying solely on clinical features without appropriate testing (rapid antigen detection test or throat culture) can lead to unnecessary antibiotic use for viral pharyngitis

4. Ignoring allergies: Failing to properly assess and document penicillin allergies before prescribing

5. Unnecessary follow-up testing: Routine post-treatment cultures are not recommended for asymptomatic patients who have completed appropriate therapy 1

While some studies suggest cephalosporins may have higher bacteriological eradication rates than penicillin 4, 3, the clinical significance of this difference is small, and penicillin remains the recommended first-line treatment due to its long track record of safety, efficacy, and cost-effectiveness.