What are the treatment options for pharyngitis in a 3rd trimester pregnant woman?

Treatment of Pharyngitis in Third Trimester Pregnancy

Penicillin V (250 mg three times daily for 10 days) or benzathine penicillin G (1.2 million units intramuscularly as a single dose) are the first-line treatments for group A streptococcal pharyngitis in third trimester pregnant women. 1

Diagnostic Confirmation Required

• Before initiating antibiotics, confirm group A streptococcal pharyngitis with either throat culture or rapid antigen detection testing (RADT), as most pharyngitis cases are viral and do not require antibiotics 1
• Treatment can be safely delayed up to 9 days after symptom onset while awaiting laboratory confirmation without increasing risk of complications like rheumatic fever 1

First-Line Antibiotic Options

For penicillin-tolerant patients:

• Oral penicillin V: 250 mg three times daily or 500 mg twice daily for 10 days 1
• Intramuscular benzathine penicillin G: 1.2 million units as a single dose—particularly useful when medication compliance is a concern 1
• Amoxicillin may be substituted for penicillin V with equivalent efficacy and is often better tolerated 1

Alternative Options for Penicillin Allergy

For non-anaphylactic penicillin allergy:

• First-generation cephalosporins for 10 days are appropriate alternatives 1, 2
• These should NOT be used in patients with immediate-type (anaphylactic) hypersensitivity to β-lactam antibiotics 1

For true penicillin allergy:

• Erythromycin (various formulations) for 10 days 1
• Azithromycin is a safe and effective alternative in pregnancy 3, 4, 5
• Clindamycin can be used if the bacterial isolate is susceptible 2

Critical Safety Considerations

Medications to strictly avoid in pregnancy:

• Tetracyclines (contraindicated after 5 weeks gestation) 6
• Fluoroquinolones (contraindicated throughout pregnancy) 3, 6
• Trimethoprim-sulfamethoxazole 3, 2
• Aminoglycosides (due to nephrotoxicity and ototoxicity) 6
• Erythromycin estolate formulation specifically should be avoided in pregnant women due to increased risk of cholestatic hepatitis 1

Important note on rifampin:

• Rifampin is relatively contraindicated in pregnant women and should not be used as adjunctive therapy for recurrent pharyngitis 1

Symptomatic Management

• Acetaminophen (paracetamol) is safe for pain and fever control throughout pregnancy 2
• Saline gargles provide safe symptomatic relief 2
• Avoid oral decongestants, especially in the first trimester, due to association with congenital malformations including gastroschisis 3, 2, 4

Clinical Pitfalls to Avoid

• Do not prescribe antibiotics for viral pharyngitis—most pharyngitis is viral and self-limited, resolving within 3-4 days even without treatment 1
• Do not use erythromycin estolate formulation in pregnant women due to hepatotoxicity risk 1
• Do not perform routine follow-up cultures or RADT in asymptomatic patients after completing appropriate antibiotic therapy 1
• Do not screen or treat asymptomatic family contacts unless they have a history of rheumatic fever 1

When to Escalate Care

• Monitor for signs of treatment failure including persistent high fever, severe headache, difficulty swallowing, or respiratory compromise 3
• Consider consultation with obstetrics for severe infections or complications requiring alternative management 2
• Peritonsillar abscess, deep space infections, or toxic shock syndrome require urgent specialist evaluation 7