What is the recommended treatment for Group A streptococcal pharyngitis in a pregnant woman?

Treatment of Strep Throat in Pregnancy

Penicillin or amoxicillin remains the drug of choice for Group A streptococcal pharyngitis in pregnant women, with no documented resistance worldwide and proven safety throughout all trimesters. 1

First-Line Treatment Regimens

Oral penicillin V is the preferred treatment:

• 250 mg three or four times daily for 10 days 1
• Proven efficacy in preventing acute rheumatic fever with excellent safety profile in pregnancy 1, 2

Amoxicillin is an equally effective alternative:

• Often preferred due to better palatability and simpler dosing 1
• 500 mg twice daily for 10 days provides equivalent bacteriologic eradication 1
• Considered relatively safe throughout pregnancy with appropriate dose adjustment 2

Intramuscular benzathine penicillin G offers a single-dose option:

• 1.2 million units as a single injection for patients ≥27 kg 1, 3
• Particularly valuable when compliance with oral therapy is uncertain 1, 3
• Proven effective in preventing rheumatic fever 1

Critical Treatment Duration

A full 10-day course is mandatory for all oral antibiotics to achieve maximal pharyngeal eradication and prevent acute rheumatic fever, even if symptoms resolve within 3–4 days. 1, 3 Shortening the course increases treatment failure rates and rheumatic fever risk. 1

Management of Penicillin Allergy in Pregnancy

For Non-Immediate (Delayed) Reactions

First-generation cephalosporins are safe and preferred:

• Cephalexin 500 mg twice daily for 10 days or cefadroxil 1 gram once daily for 10 days 1, 3
• Cross-reactivity risk is only 0.1% in patients with delayed, mild penicillin reactions 4
• Beta-lactam antibiotics with dose adjustment are considered relatively safe in pregnancy 2

For Immediate/Anaphylactic Reactions

Avoid all beta-lactams due to up to 10% cross-reactivity risk. 1, 4

Azithromycin is the preferred alternative in pregnancy:

• 500 mg once daily for 5 days 3
• Macrolides (including azithromycin) are considered relatively safe, though erythromycin and clarithromycin carry certain risks 2
• Macrolide resistance in the United States is 5–8%, which is a consideration but acceptable when beta-lactams cannot be used 4, 3

Clindamycin is an alternative option:

• 300 mg three times daily for 10 days 4, 3
• Considered relatively safe in pregnancy 2
• Only ~1% resistance among Group A Streptococcus in the United States 4, 3

Erythromycin can be used but with important caveats:

• Dosing varies by formulation, typically 250–500 mg every 6–12 hours for 10 days 1
• Erythromycin estolate is specifically contraindicated in pregnancy due to risk of cholestatic hepatitis, which occurs more frequently in pregnant women 1
• Other erythromycin formulations (stearate, ethyl succinate, base) are acceptable 1

Diagnostic Confirmation Before Treatment

Confirm Group A Streptococcus infection with rapid antigen detection test (RADT) or throat culture before prescribing antibiotics, as clinical features alone cannot reliably distinguish bacterial from viral pharyngitis. 3 However, if clinical or epidemiological evidence creates high suspicion, therapy can be initiated while awaiting results, then discontinued if testing is negative. 1, 3

Key Treatment Goals in Pregnancy

The primary objectives extend beyond symptom relief:

• Prevention of acute rheumatic fever (therapy can be safely delayed up to 9 days after symptom onset and still prevent this complication) 1, 3
• Prevention of suppurative complications 3
• Reduction of transmission to close contacts 3
• Rapid symptom resolution 1, 3

Common Pitfalls to Avoid

Do not use erythromycin estolate in pregnant women due to increased risk of cholestatic hepatitis. 1

Do not prescribe cephalosporins to pregnant women with immediate/anaphylactic penicillin reactions due to ~10% cross-reactivity risk. 1, 4

Do not shorten the antibiotic course below 10 days (except azithromycin's 5-day regimen), as this dramatically increases treatment failure and rheumatic fever risk. 1, 3

Do not order routine post-treatment cultures in asymptomatic patients who have completed therapy; reserve testing for special circumstances such as persistent symptoms or history of rheumatic fever. 3

Adjunctive Symptomatic Management

Acetaminophen is safe for fever and throat pain throughout pregnancy. 4 Non-selective NSAIDs can be used until the 32nd week of pregnancy but should be avoided thereafter. 2