What are the recommended antibiotics for treating bacterial sinusitis?

Antibiotic Recommendations for Bacterial Sinusitis

Amoxicillin-clavulanate is the first-line treatment for most patients with acute bacterial sinusitis, with a standard dose of 875/125 mg twice daily for 5-7 days. 1

First-Line Treatment Options

Adults:

• First choice: Amoxicillin-clavulanate 875/125 mg twice daily for 5-7 days
• High-prevalence of resistant S. pneumoniae: High-dose amoxicillin-clavulanate (2000 mg amoxicillin component with 125 mg clavulanate twice daily) for 5-7 days 1

Children:

• First choice: Amoxicillin-clavulanate (45 mg/6.4 mg per kg per day)
• High-prevalence of resistant S. pneumoniae: High-dose amoxicillin-clavulanate (90 mg/6.4 mg per kg per day) 2
• Duration: Minimum course of 10 days, or continue for 7 days after symptom resolution 1

Alternative Options for Penicillin Allergy

• Non-severe allergy:

  • Cefuroxime 250-500 mg twice daily
  • Cefpodoxime 200-400 mg twice daily
  • Cefdinir 300-600 mg twice daily 1

• Severe allergy:

  • Doxycycline (for mild-moderate infections)
  • Respiratory fluoroquinolones: Levofloxacin 500 mg daily or Moxifloxacin 400 mg daily
  • Clindamycin plus a third-generation oral cephalosporin (cefixime or cefpodoxime) 1

Treatment Failure Considerations

If symptoms persist or worsen after 72 hours of initial therapy:

• Switch to broader-spectrum antibiotic based on initial treatment
• Consider respiratory fluoroquinolones (levofloxacin 500 mg daily or moxifloxacin 400 mg daily) 2, 1

Pathogen Considerations

The most common bacterial pathogens in acute sinusitis are:

• Streptococcus pneumoniae
• Haemophilus influenzae
• Moraxella catarrhalis 3, 4

In chronic sinusitis, consider coverage for:

• Anaerobic bacteria
• Staphylococcus aureus 4

For immunocompromised patients, consider coverage for Pseudomonas aeruginosa 1, 4

Important Clinical Considerations

Diagnosis

Acute bacterial sinusitis typically presents with:

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

Adjunctive Therapies

• Intranasal saline irrigation
• Intranasal corticosteroids
• Short-course decongestants
• Adequate hydration 1

Treatment Duration

Recent evidence supports shorter treatment courses:

• 5-7 days for newer antibiotics in adults with uncomplicated acute maxillary sinusitis
• 10-14 days for older antibiotics or in children 1, 5

Common Pitfalls to Avoid

1. Overtreatment: Not all sinusitis is bacterial; most cases of acute nasopharyngitis are viral and self-limiting
2. Undertreatment: Using inadequate dosing or duration, especially in areas with high resistance rates
3. Ignoring risk factors: Recent antibiotic use significantly increases risk of resistant pathogens 2
4. Neglecting underlying conditions: Allergic rhinitis, nonallergic rhinitis, and GERD can contribute to sinusitis and should be addressed 1

When to Consider Referral

• Refractory sinusitis despite appropriate antibiotic therapy
• Recurrent sinusitis
• Sinusitis associated with unusual opportunistic infections
• Suspected anatomical abnormalities requiring surgical evaluation 1

A recent clinical trial found no significant benefit of high-dose versus standard-dose amoxicillin-clavulanate for adults with acute sinusitis, with similar clinical improvement rates at day 3 (36.4% vs 44.3%) 6. However, in areas with high prevalence of resistant S. pneumoniae, high-dose therapy may still be warranted as recommended by current guidelines 1.