What is the recommended treatment for bacterial sinusitis?

Treatment of Bacterial Sinusitis

Amoxicillin-clavulanate is recommended as first-line empiric antimicrobial therapy for acute bacterial sinusitis in both adults and children, with treatment duration of 5-7 days for adults and 10-14 days for children. 1

Diagnosis of Bacterial Sinusitis

Bacterial sinusitis should be diagnosed when patients present with:

• Persistent symptoms for >10 days without improvement
• Severe symptoms (high fever and purulent nasal discharge for 3-4 consecutive days)
• Worsening symptoms after initial improvement ("double-worsening") 1, 2

First-Line Treatment

Adults:

• Amoxicillin-clavulanate 875/125 mg twice daily for 5-7 days 1
• High-dose amoxicillin-clavulanate (2000 mg amoxicillin component twice daily) should be considered in:
  • Regions with high prevalence of penicillin-resistant S. pneumoniae
  • Severe infection
  • Immunocompromised hosts
  • Extremes of age
  • Recent hospitalization
  • Recent antibiotic use 1

Children:

• Amoxicillin-clavulanate with appropriate weight-based dosing for 10-14 days 1
• Pediatric dosing: 45 mg/kg BID for amoxicillin component 3

Alternative Antibiotic Options (for penicillin allergy or treatment failure)

• Doxycycline (adults only)
• Cefuroxime: 250-500 mg BID (adults), 7.5 mg/kg BID (children)
• Cefpodoxime: 200-400 mg BID (adults), 5 mg/kg BID (children)
• Cefdinir
• Levofloxacin: 500 mg QD or 750 mg QD for 5 days (reserved for treatment failures or when other options cannot be used) 1, 3, 4

Note: First-generation cephalosporins like cephalexin have poor coverage for H. influenzae and are inappropriate for sinusitis treatment. Cefixime and ceftibuten have poor activity against S. pneumoniae and should not be used for acute bacterial sinusitis. 3

Adjunctive Therapies

• Intranasal saline irrigation with either physiologic or hypertonic saline 1
• Intranasal corticosteroids, especially in patients with a history of allergic rhinitis 1
• Topical or oral decongestants and antihistamines are not recommended 1

Treatment Reassessment

• Reassess if symptoms worsen after 48-72 hours of initial therapy or fail to improve after 3-5 days 1
• If treatment failure occurs, consider:
  • Alternative diagnosis
  • Imaging studies
  • Switching to an alternative antibiotic regimen
  • Referral to a specialist 1

Common Pathogens

The most common bacterial pathogens in acute bacterial sinusitis are:

• Streptococcus pneumoniae (including penicillin-resistant strains)
• Haemophilus influenzae (often β-lactamase producing)
• Moraxella catarrhalis (almost always β-lactamase producing)
• Staphylococcus aureus (more common in chronic sinusitis) 3, 5

Important Clinical Considerations

• Antibiotic treatment should be reserved for bacterial sinusitis; viral sinusitis should not receive antibiotics 3
• Short-course therapy (5-7 days) for adults has been shown to be as effective as traditional 10-14 day courses 6
• Recent research shows no benefit of high-dose amoxicillin-clavulanate over standard-dose for most adult patients with acute bacterial sinusitis 7
• Treatment failure may indicate resistant pathogens, inadequate penetration of antibiotics, or an incorrect diagnosis 1

By following these evidence-based guidelines, clinicians can effectively treat bacterial sinusitis while minimizing unnecessary antibiotic use and the development of antimicrobial resistance.