What is the recommended antibiotic for streptococcal pharyngitis in pregnancy?

Recommended Antibiotic for Streptococcal Pharyngitis in Pregnancy

Penicillin or amoxicillin remains the drug of choice for treating streptococcal pharyngitis during pregnancy, as these are FDA pregnancy category B medications with proven safety and efficacy. 1

Treatment Algorithm

First-Line Therapy (No Penicillin Allergy)

• Penicillin V: 500 mg orally twice daily for 10 days 1
• Amoxicillin: 500 mg orally twice daily (or 1000 mg once daily) for 10 days 1
  • Amoxicillin is often preferred due to better palatability and once-daily dosing option, which may enhance adherence 1
  • Both penicillin and amoxicillin are safe during pregnancy and have narrow antimicrobial spectra 1

Alternative for Intramuscular Administration

• Benzathine penicillin G: 1.2 million units intramuscularly as a single dose 1
  • This option is particularly valuable when adherence to oral therapy is uncertain 1
  • Ensures complete treatment course and prevents rheumatic fever 1

Treatment for Penicillin-Allergic Pregnant Patients

Non-Immediate (Non-Anaphylactic) Penicillin Allergy

• First-generation cephalosporins are the preferred alternative 1, 2, 3
  • Cephalexin: 500 mg orally twice daily for 10 days 2, 4
  • Cefadroxil: 1 gram orally once daily for 10 days 2, 4
  • These are safe during pregnancy (penicillin and cephalosporin are the safest antibiotic classes in pregnancy) 1

Immediate/Anaphylactic Penicillin Allergy

Avoid all beta-lactams (including cephalosporins) due to up to 10% cross-reactivity risk 1, 2, 3

Alternative options include:

• Azithromycin: 500 mg orally on day 1, then 250 mg daily for days 2-5 (total 5 days) 1, 2, 5

  • FDA-approved for 5-day course due to prolonged tissue half-life 1, 5
  • Pregnancy category B 5
  • Be aware that macrolide resistance rates are approximately 5-8% in the United States 1, 2

• Erythromycin: Dosage varies by formulation, typically 250-500 mg orally every 6-12 hours for 10 days 1, 6

  • Critical caveat: Erythromycin estolate should NOT be used in pregnant women due to risk of cholestatic hepatitis 1, 6
  • Other erythromycin formulations (stearate, ethyl succinate, base) are acceptable 1, 6
  • Higher gastrointestinal side effects compared to other macrolides 1

• Clindamycin: 300 mg orally three times daily for 10 days 1, 2

  • Approximately 1% resistance rate in the United States 1, 2
  • Particularly effective for treatment failures and chronic carriers 2, 3

Critical Treatment Duration Requirements

All antibiotics except azithromycin require a full 10-day course to achieve maximal pharyngeal eradication of Group A Streptococcus and prevent acute rheumatic fever 1, 2. Therapy can be safely postponed up to 9 days after symptom onset and still prevent rheumatic fever, but once started, the full course must be completed 1.

Important Caveats and Common Pitfalls

• Do not use tetracyclines, sulfonamides, trimethoprim-sulfamethoxazole, or fluoroquinolones during pregnancy for streptococcal pharyngitis 1
• Penicillin-resistant Group A Streptococcus has never been documented, making penicillin the most reliable choice 1
• Do not prescribe shorter courses than recommended (except azithromycin's 5-day regimen), as this leads to treatment failure and increased risk of rheumatic fever 1, 2
• When prescribing macrolides, consider local resistance patterns, as resistance varies geographically 1, 2
• Cephalosporins should only be used in patients without immediate/anaphylactic penicillin reactions due to cross-reactivity risk 1, 2, 3

Adjunctive Therapy

• Acetaminophen is safe and recommended for fever and pain control during pregnancy 2
• Avoid aspirin due to potential fetal risks 2
• Corticosteroids are not recommended as adjunctive therapy 2