What is the recommended dose and antibiotic (abx) for bacterial sinus infection?

Recommended Dose and Antibiotic for Bacterial Sinus Infection

Amoxicillin-clavulanate (875/125 mg twice daily for 5-7 days) is the recommended first-line antibiotic therapy for bacterial sinusitis. 1

First-Line Treatment Options

• Amoxicillin-clavulanate:

  • Standard dose: 875/125 mg twice daily for 5-7 days 1
  • High-dose option: 2000 mg amoxicillin component twice daily for 5-7 days (for patients with risk factors for resistant organisms) 1

• Patient stratification based on antibiotic exposure:

  • For patients who have NOT received antibiotics in the previous 4-6 weeks (mild disease):

    • Amoxicillin-clavulanate 875/125 mg twice daily 2
    • Amoxicillin 1.5-4 g/day 2

  • For patients who HAVE received antibiotics in the previous 4-6 weeks or have moderate disease:

    • High-dose amoxicillin-clavulanate (4 g/250 mg per day) 2
    • Respiratory fluoroquinolones (e.g., levofloxacin 750 mg once daily for 5 days) 2, 3

Alternative Options for Penicillin-Allergic Patients

• Cephalosporins (if no history of anaphylaxis to penicillin):

  • Cefuroxime: 500 mg twice daily for 5-7 days 1
  • Cefpodoxime: 200-400 mg twice daily for 5-7 days 1
  • Cefdinir: 300-600 mg twice daily for 5-7 days 1

• For true penicillin allergy:

  • Trimethoprim-sulfamethoxazole 1
  • Doxycycline 2
  • Macrolides (azithromycin, clarithromycin) - note that these have bacteriologic failure rates of 20-25% 2

Reserve Fluoroquinolones

• Fluoroquinolones should be reserved for:

  • Treatment failures
  • Complicated sinusitis (frontal, sphenoidal)
  • Known resistant pathogens 1

• When needed, levofloxacin (500 mg once daily) or moxifloxacin (400 mg once daily) for 5-7 days provide better pneumococcal coverage than ciprofloxacin 1, 3

Treatment Duration and Monitoring

• Standard duration: 5-7 days for uncomplicated cases 1
• Reassess after 72 hours of treatment 2, 1
• If no improvement after 72 hours, consider:
  • Alternative diagnosis
  • Resistant pathogens
  • Need for imaging or specialist referral 1

Important Clinical Considerations

• Recent antibiotic use increases risk of resistant organisms 2

• Risk factors for resistant organisms include:

  • Recent antibiotic use
  • Areas with high prevalence of resistant S. pneumoniae
  • Severe symptoms or worsening course 1

• The twice-daily dosing regimen of amoxicillin-clavulanate (875/125 mg) has been shown to be as effective as the three-times-daily regimen (500/125 mg) 4

Common Pitfalls to Avoid

1. Using fluoroquinolones as first-line therapy
2. Not reassessing treatment response after 72 hours
3. Inadequate duration of therapy
4. Treating viral URI as bacterial sinusitis
5. Unnecessary imaging 1

Studies show that amoxicillin-clavulanate results in significantly more cures and fewer failures than placebo in bacterial sinusitis 5, supporting the recommendation for antibiotic therapy in confirmed cases.