What are safe antibiotics for treating sinus infections during pregnancy?

Safe Antibiotics for Sinus Infection in Pregnancy

Penicillins and cephalosporins are the safest antibiotics for treating sinus infections during pregnancy and should be your first-line choices. 1, 2

First-Line Antibiotic Recommendations

Use amoxicillin as your primary antibiotic choice for bacterial sinusitis in pregnancy, as it has decades of clinical experience demonstrating no teratogenic effects and is compatible throughout all trimesters. 2 The recommended dosing is high-dose amoxicillin (90 mg/kg/day in 2 divided doses, maximum 1g every 12 hours) to overcome penicillin-resistant S. pneumoniae. 3

Alternative Safe Options:

• Cephalosporins (particularly first-generation like cephalexin) are equally safe throughout pregnancy and should be used for patients with non-anaphylactic penicillin allergy. 1, 2

• Azithromycin is recommended as a safe first-line choice, particularly for first-trimester sinusitis, due to its excellent safety profile and effectiveness. 3, 4 Clinical trials demonstrate 85-88% cure rates for respiratory infections with minimal gastrointestinal side effects. 4

• Amoxicillin-clavulanate provides broader coverage against β-lactamase-producing organisms when needed. 3

When to Use Antibiotics

Reserve antibiotics for true bacterial sinusitis only, characterized by: 3

• Symptoms persisting ≥10 days without improvement, OR
• Worsening symptoms after initial improvement at 5-7 days (double worsening pattern)
• Endoscopic evidence of purulence 1

Before prescribing antibiotics, initiate conservative management with saline nasal rinses, adequate hydration, rest, and warm facial packs. 3

Antibiotics That Must Be Avoided

Never prescribe these antibiotics during pregnancy: 1, 2, 3

• Tetracyclines (including doxycycline) - cause tooth discoloration, bone growth suppression, and potential maternal fatty liver after the fifth week of pregnancy
• Fluoroquinolones - risk of cartilage damage throughout pregnancy
• Trimethoprim-sulfamethoxazole - increased risk of preterm birth, low birthweight, kernicterus, hyperbilirubinemia, and fetal hemolytic anemia, especially in first trimester
• Aminoglycosides - nephrotoxicity and ototoxicity risks
• Long-term macrolides or doxycycline - not recommended for chronic rhinosinusitis maintenance 1

Adjunctive Safe Therapies

Intranasal corticosteroid sprays are safe throughout pregnancy and should be continued or initiated for symptom control. 1, 2 Specifically, budesonide, fluticasone, and mometasone at recommended doses are safe for chronic rhinosinusitis maintenance during pregnancy. 1, 3

Avoid oral decongestants, especially during the first trimester, due to potential association with congenital malformations. 5, 3

Critical Trimester-Specific Considerations

The first trimester carries the highest risk for teratogenicity, so antibiotics should only be used when clearly needed for documented bacterial infection. 2, 3 However, when bacterial sinusitis is confirmed, do not withhold appropriate antibiotics—penicillins and cephalosporins remain safe even in the first trimester. 2, 3

Oral corticosteroids should be avoided in the first trimester but may be considered after the first trimester for severe chronic rhinosinusitis exacerbations, especially if causing asthma exacerbation, with obstetrician consultation. 1

Common Pitfalls to Avoid

• Do not withhold necessary antibiotics due to pregnancy concerns when using safe agents like penicillins or cephalosporins—untreated bacterial sinusitis poses greater maternal-fetal risks. 1, 6

• Consult with the patient's obstetrician for severe infections, complications, or when considering second-line agents. 1, 2, 3

• Monitor for treatment failure red flags: high fever persisting despite antibiotics, severe headache, visual changes, or periorbital swelling, which may indicate orbital cellulitis, meningitis, or abscess formation requiring urgent specialist consultation. 3

• Coordinate care for patients with underlying asthma, as respiratory infections can trigger exacerbations requiring additional management. 1, 2

Breastfeeding Compatibility

Penicillins, cephalosporins, and macrolides are all compatible with breastfeeding and considered low risk. 2 Monitor breastfed infants for gastrointestinal effects, and note that antibiotics in breast milk may cause falsely negative cultures if a febrile infant requires evaluation. 2