Treatment of Streptococcal Pharyngitis in Pregnancy
Penicillin or amoxicillin for 10 days is the recommended first-line treatment for streptococcal pharyngitis in pregnant women, with proven safety for both mother and fetus. 1, 2
First-Line Antibiotic Therapy
Penicillin and amoxicillin remain the drugs of choice based on their narrow spectrum of activity, proven efficacy, excellent safety profile in pregnancy, and low cost. 3, 1
Recommended Dosing Regimens:
- Penicillin V: 500 mg orally twice daily for 10 days 1, 2
- Amoxicillin: 500 mg orally twice daily OR 1000 mg once daily for 10 days 1, 2
Amoxicillin is often preferred over penicillin V due to better palatability and the option for once-daily dosing, which may enhance adherence. 3 The once-daily amoxicillin regimen (1000 mg) has been shown effective in comparative trials and offers a practical advantage for pregnant patients. 3
Critical point: Penicillin-resistant Group A Streptococcus has never been documented, making penicillin the most reliable choice. 3, 1
Management of Penicillin-Allergic Pregnant Patients
The approach differs based on allergy severity:
For Non-Anaphylactic Penicillin Allergy:
- First-generation cephalosporins (cephalexin or cefadroxil) for 10 days 1, 2
- Cefazolin is specifically recommended by CDC as the preferred alternative in pregnancy 2
For Anaphylactic/Immediate Hypersensitivity:
- Azithromycin: 500 mg orally on day 1, then 250 mg daily for days 2-5 (total 5 days) 1, 4
- Clindamycin: 300 mg orally three times daily for 10 days (if susceptibility testing confirms the isolate is susceptible) 1, 2
Important caveat: Macrolide resistance varies geographically, so consider local resistance patterns when prescribing azithromycin. 1 Clindamycin has a low resistance rate of approximately 1% in the United States. 1
Critical Treatment Duration Requirements
A full 10-day course is essential for all antibiotics except azithromycin to achieve maximal pharyngeal eradication of Group A Streptococcus and prevent acute rheumatic fever. 3, 1 This duration must be completed regardless of symptom improvement, which typically occurs within 24-48 hours of starting therapy. 3
Azithromycin is the only FDA-approved antibiotic for a 5-day course in streptococcal pharyngitis. 3, 4
Antibiotics to Avoid During Pregnancy
Absolutely contraindicated in pregnant women with streptococcal pharyngitis: 1, 2
- Tetracyclines (including doxycycline)
- Sulfonamides
- Trimethoprim-sulfamethoxazole
- Fluoroquinolones
- Erythromycin estolate (risk of cholestatic hepatitis) 1, 5
Other erythromycin formulations may be used as alternatives but are not preferred. 5
Important Clinical Considerations
Diagnostic Testing:
Treatment should be based on positive throat culture or rapid antigen detection testing (RADT), not empiric therapy. 2 Withholding antibiotics in patients with negative microbiological tests is a quality care indicator. 2
Asymptomatic Carriers:
Do not treat asymptomatic household contacts or carriers, as antimicrobial therapy is much less effective at eradicating Group A Streptococci from carriers than from patients with acute infections. 3, 2
Follow-up:
Routine post-treatment throat cultures are not recommended. 3 However, patients with worsening symptoms after appropriate antibiotic initiation or symptoms lasting 5 days after starting treatment should be reevaluated. 6
Common Pitfalls to Avoid
- Do not use shorter courses (except azithromycin 5 days) even if symptoms resolve quickly—this risks treatment failure and rheumatic fever. 3, 1
- Do not prescribe broad-spectrum antibiotics when narrow-spectrum penicillin is appropriate—this contributes to antibiotic resistance. 3
- Do not treat based on clinical suspicion alone without confirmatory testing in adults, as only 10% of adults with sore throat have streptococcal pharyngitis. 6
- Do not use erythromycin estolate specifically in pregnancy due to hepatotoxicity risk. 1, 5