What is the preferred antibiotic for acute bacterial sinusitis?

Preferred Antibiotic Treatment for Acute Bacterial Sinusitis

Amoxicillin-clavulanate is the preferred first-line antibiotic for acute bacterial sinusitis, with amoxicillin as an acceptable alternative in uncomplicated cases. 1, 2

Diagnostic Criteria for Acute Bacterial Sinusitis

Before initiating antibiotics, confirm the diagnosis of acute bacterial sinusitis based on one of these clinical presentations:

• Persistent symptoms: Nasal discharge or cough for >10 days without improvement
• Severe symptoms: High fever (>39°C/102.2°F) with purulent nasal discharge or facial pain for ≥3 consecutive days
• Worsening symptoms: Initial improvement followed by worsening symptoms ("double sickening") 1, 2

First-Line Antibiotic Recommendations

Adults:

• First choice: Amoxicillin-clavulanate 875/125 mg twice daily for 5-7 days 1, 2
• Alternative: Amoxicillin 500-875 mg three times daily for 5-7 days (in areas with low resistance patterns) 1

Children:

• First choice: Amoxicillin-clavulanate (appropriate weight-based dosing) 1
• Alternative: Amoxicillin (high-dose) for uncomplicated cases 1

Alternative Options for Penicillin-Allergic Patients

• Doxycycline (adults only) 1, 2
• Respiratory fluoroquinolones (levofloxacin 500 mg daily or moxifloxacin 400 mg daily) 1, 2
• Cephalosporins: Cefdinir (300-600 mg twice daily), cefuroxime (250-500 mg twice daily), or cefpodoxime (200-400 mg twice daily) 2

Treatment Failure Management

If no improvement after 72 hours of initial therapy:

• If started on amoxicillin: Switch to high-dose amoxicillin-clavulanate 1
• If started on amoxicillin-clavulanate: Consider clindamycin plus cefixime, linezolid plus cefixime, or levofloxacin 1

Adjunctive Therapies

These therapies can provide symptomatic relief and potentially reduce antibiotic need:

• Intranasal saline irrigation
• Intranasal corticosteroids
• Short-term nasal decongestants
• Analgesics for pain
• Antipyretics for fever 1, 2

Important Clinical Considerations

• Recent evidence suggests that amoxicillin-clavulanate and amoxicillin have similar treatment failure rates in children, but amoxicillin-clavulanate is associated with more gastrointestinal side effects and yeast infections 3
• The American Academy of Otolaryngology-Head and Neck Surgery recommends amoxicillin-clavulanate for patients over 65 years due to broader spectrum coverage 2
• Local resistance patterns should guide antibiotic selection, with amoxicillin-clavulanate preferred in areas with high prevalence of beta-lactamase producing organisms 2
• Macrolides (azithromycin, clarithromycin) are not recommended as first-line due to high resistance rates 2

When to Refer to a Specialist

Refer immediately if any of these complications develop:

• Orbital involvement (proptosis, impaired visual acuity, painful extraocular mobility)
• Neurological symptoms (altered mental status, severe headache)
• Persistent symptoms despite appropriate antibiotic therapy 1, 2

Treatment Duration

While the optimal duration is not definitively established, 5-7 days of therapy is generally recommended for uncomplicated cases in adults, with possible extension to 10-14 days for more severe or complicated cases 1, 2, 4