Recommended Antibiotics for Acute Bacterial Sinusitis in Adults
For adults with acute bacterial sinusitis requiring antibiotic therapy, amoxicillin with or without clavulanate should be prescribed as first-line therapy for 5 to 10 days. 1
Diagnostic Criteria for Antibiotic Treatment
Antibiotics should only be prescribed when one of these clinical presentations is present:
- Persistent symptoms lasting ≥10 days without improvement 2
- Severe symptoms with high fever (≥39°C/102°F) and purulent nasal discharge or facial pain 2
- "Double-sickening" (worsening symptoms after initial improvement) 2
First-Line Antibiotic Selection
Standard Cases
- Amoxicillin alone (standard dose): First choice for uncomplicated cases with no risk factors for resistant pathogens 1, 2
- Duration: 5-7 days for uncomplicated cases with good clinical response 2
High-Risk Cases
Risk factors for resistant pathogens include:
- Antibiotic use within the past month 1
- Close contact with treated individuals or healthcare environment 1
- Prior antibiotic failure 1
- Age >65 years 1
- Immunocompromised status 1
- Moderate to severe infection 1
Penicillin-Allergic Patients
For patients with penicillin allergy, alternative options include:
- Doxycycline 1
- Respiratory fluoroquinolones (levofloxacin or moxifloxacin) - reserve for severe cases due to side effect profile 1, 3
- Combination therapy: Clindamycin plus a third-generation oral cephalosporin (cefixime or cefpodoxime) for non-type I hypersensitivity 1
Treatment Duration
- Standard duration: 5-10 days 1, 2
- Shorter courses (5-7 days): Equally effective for uncomplicated cases with good response, with fewer adverse events 1, 2
- Longer courses (7-10 days): Consider for severe disease or persistent symptoms 1, 2
Treatment Failure Management
If a patient fails to improve after 7 days of initial management or worsens at any time:
- For patients initially managed with observation: Begin antibiotic therapy 1, 2
- For patients initially managed with antibiotics: Change to a different antibiotic 1, 2
Important Considerations
- Watchful waiting is appropriate for mild cases, delaying antibiotics for up to 7 days while providing symptomatic treatment 1, 2
- Adverse events are more common with antibiotic therapy (odds ratio 1.87-2.10), particularly gastrointestinal effects 1
- Macrolides (e.g., clarithromycin) and trimethoprim-sulfamethoxazole are not recommended for initial therapy due to high resistance rates 1
- High-dose vs. standard-dose amoxicillin-clavulanate: Recent studies show mixed results, with one study showing no benefit of high-dose therapy 4, while another showed improved early response with immediate-release high-dose formulation 5
Common Pitfalls to Avoid
- Overuse of broad-spectrum antibiotics when amoxicillin would be sufficient 1
- Prescribing antibiotics for viral sinusitis (most cases resolve spontaneously) 1, 2
- Inadequate duration of therapy leading to treatment failure 1
- Failure to recognize risk factors for resistant pathogens 1
- Using macrolides as first-line therapy despite high resistance rates (>40% for S. pneumoniae) 1