What antibiotics are recommended for treating sinus infections?

Antibiotic Therapy for Sinus Infections

Amoxicillin-clavulanate (875/125 mg twice daily for 5-7 days) is the first-line antibiotic treatment for bacterial sinusitis, with high-quality evidence supporting its efficacy. 1

First-Line Treatment Options

The most recent guidelines from multiple medical societies, including the American Academy of Family Physicians, American Academy of Pediatrics, and Infectious Diseases Society of America, strongly recommend amoxicillin-clavulanate as the first-line therapy for bacterial sinusitis:

• Amoxicillin-clavulanate: 875/125 mg twice daily for 5-7 days 1

This recommendation accounts for the increasing prevalence of beta-lactamase-producing organisms and penicillin-resistant Streptococcus pneumoniae that are commonly implicated in sinusitis.

Patient Stratification for Treatment

Treatment should be selected based on:

1. Prior antibiotic exposure:

   • No recent antibiotics (past 4-6 weeks): Standard-dose amoxicillin-clavulanate
   • Recent antibiotic use: High-dose amoxicillin-clavulanate (4 g/250 mg per day) 1

2. Disease severity:

   • Mild disease: Standard-dose therapy
   • Moderate-severe disease: High-dose therapy or respiratory fluoroquinolones 1

3. Anatomical location of sinusitis:

   • Maxillary sinusitis: Amoxicillin-clavulanate, 2nd/3rd generation cephalosporins, or pristinamycin 2
   • Frontal, ethmoidal, or sphenoidal sinusitis: Consider adding fluoroquinolones active against pneumococci (levofloxacin, moxifloxacin) 2

Alternative Options for Penicillin-Allergic Patients

For patients with true penicillin allergy, the following alternatives are recommended:

• Cephalosporins: Cefuroxime (500 mg twice daily), cefpodoxime (200-400 mg twice daily), or cefdinir (300-600 mg twice daily) 1
• Respiratory fluoroquinolones: Levofloxacin (500 mg once daily) or moxifloxacin (400 mg once daily) 1, 3
• Other options: Doxycycline or trimethoprim-sulfamethoxazole 1
• Macrolides (azithromycin, clarithromycin): Note that these have bacteriologic failure rates of 20-25% and should be used with caution 1, 4

Treatment Duration and Assessment

• Standard duration: 5-7 days for uncomplicated cases 1
• Reassessment: All patients should be reassessed after 72 hours of treatment 1
• Treatment failure: Consider alternative diagnosis, resistant pathogens, or need for imaging if no improvement after 72 hours 1

Common Pitfalls to Avoid

1. Treating viral URI as bacterial sinusitis: Ensure diagnosis meets criteria for bacterial infection
2. Using fluoroquinolones as first-line therapy: Reserve these for treatment failures or specific anatomical locations
3. Using macrolides as first-line therapy: Higher failure rates due to resistance
4. Inadequate duration of therapy: Too short courses may lead to treatment failure
5. Not reassessing after 72 hours: Critical timepoint for evaluating response

Special Considerations

• Complicated sinusitis: Signs include meningeal syndrome, exophthalmos, palpebral edema, ocular mobility disorders, or severe pain preventing sleep - these require immediate referral and possibly parenteral antibiotics 2
• Frontal, ethmoidal, or sphenoidal sinusitis: These are considered more serious and warrant more aggressive therapy than maxillary sinusitis 2

Adjunctive Therapies

• Decongestants: May help improve sinus drainage
• Intranasal corticosteroids: Can reduce inflammation
• Saline irrigation: Helps clear secretions
• Analgesics: For pain management

By following these evidence-based recommendations, clinicians can effectively treat bacterial sinusitis while minimizing antibiotic resistance and adverse effects.