What is the recommended treatment for bacterial sinusitis in pregnancy?

Treatment of Bacterial Sinusitis in Pregnancy

For bacterial sinusitis in pregnancy, use amoxicillin or amoxicillin-clavulanate as first-line antibiotic therapy when treatment is indicated, with azithromycin reserved as an alternative for penicillin-allergic patients. 1

When to Initiate Antibiotics

• Reserve antibiotics for true bacterial sinusitis characterized by symptoms persisting ≥10 days without improvement, or worsening symptoms after initial improvement at 5-7 days 2
• Look for endoscopic evidence of purulence when available to confirm bacterial infection 1
• The most common bacterial pathogens in pregnancy are Streptococcus pneumoniae (43.2%), Haemophilus influenzae (22.1%), and Moraxella catarrhalis (10.5%), with S. pneumoniae being particularly prevalent in the third trimester 3

First-Line Antibiotic Selection

Penicillin and cephalosporin antibiotics are the safest classes for treating bacterial sinusitis in pregnancy. 1

• Amoxicillin-clavulanate provides broader coverage against β-lactamase-producing organisms and is recommended as first-line therapy 2
• High-dose amoxicillin (90 mg/kg/day in 2 divided doses, maximum 1g every 12 hours) can overcome most penicillin-resistant S. pneumoniae if amoxicillin-clavulanate is not available 2
• Note that pregnancy alters pharmacokinetics, requiring increased dosages of beta-lactam antibiotics for adequate treatment 4, 5, 6

Alternative Antibiotic for Penicillin Allergy

• Azithromycin is the preferred alternative for penicillin-allergic pregnant patients 2, 7
• Azithromycin dosing: 500 mg once daily for 3 days for acute bacterial sinusitis 8
• Azithromycin is FDA Pregnancy Category B with no evidence of fetal harm in animal studies, though adequate human studies are lacking 8
• First-generation cephalosporins may be used for non-anaphylactic penicillin allergies 2, 9

Antibiotics to Strictly Avoid

Never prescribe tetracyclines, fluoroquinolones, trimethoprim-sulfamethoxazole, or aminoglycosides during pregnancy due to documented fetal risks. 1, 2

• Long-term macrolide or doxycycline use for chronic rhinosinusitis maintenance is contraindicated during pregnancy 1

Conservative Measures (Start Before or Alongside Antibiotics)

• Saline nasal rinses are the primary therapy for symptom relief and should be initiated first 2, 7
• Adequate hydration, rest, and warm facial packs provide additional comfort 2
• Topical corticosteroid nasal sprays (budesonide, fluticasone, or mometasone) are safe at recommended doses throughout pregnancy and effectively control nasal inflammation 1, 2, 7

Medications to Avoid for Symptom Relief

• Oral decongestants must be avoided, especially in the first trimester, due to association with congenital malformations including gastroschisis 2, 9, 7
• Nasal decongestants provide temporary relief but should be restricted to only a few days to prevent rhinitis medicamentosa from overuse 10, 4, 5

Role of Oral Corticosteroids

• Oral corticosteroids may be considered after the first trimester only for severe disease, particularly if causing asthma exacerbation 1
• First trimester use carries the greatest risk of teratogenicity, including cleft lip/palate, preeclampsia, preterm delivery, and low birth weight 1
• Consultation with the patient's obstetrician is mandatory before prescribing oral corticosteroids 1
• Patients require diabetes testing prior to use due to hyperglycemia risk 1

Diagnostic Considerations

• Differentiating bacterial sinusitis from pregnancy rhinitis can be challenging, as both present with nasal congestion 4, 5, 6
• Pregnancy rhinitis affects one in five pregnant women, appears in any gestational week, and resolves within 2 weeks postpartum 10, 4
• Nasendoscopy of a decongested nose is the diagnostic method of choice 10
• Maxillary sinus puncture/irrigation is both diagnostic and therapeutic for purulent sinusitis and may need to be repeated 4, 5, 6

Red Flags Requiring Urgent Evaluation

Monitor for complications indicating treatment failure: high fever persisting despite antibiotics, severe headache, visual changes, or periorbital swelling, which may indicate orbital cellulitis, meningitis, or abscess formation. 2

Key Clinical Pitfalls to Avoid

• Do not treat viral upper respiratory infections with antibiotics before 10 days of symptoms 2
• Do not use third-generation cephalosporins with poor pneumococcal coverage 2
• Do not prescribe oral decongestants in any trimester 2
• Do not use standard antibiotic dosing—increase beta-lactam doses to account for pregnancy pharmacokinetics 4, 5, 6
• Do not assume all nasal congestion in pregnancy is pregnancy rhinitis—bacterial sinusitis requires aggressive treatment with antibiotics and potentially antral irrigation 4, 5, 6