What is the recommended treatment for sinus infections?

Treatment of Acute Bacterial Sinusitis

For uncomplicated acute bacterial sinusitis in adults, start with amoxicillin 500 mg twice daily (or 875 mg twice daily for more severe infections) for 7-10 days, or use amoxicillin-clavulanate 875/125 mg twice daily for 5-10 days as first-line therapy. 1

When to Start Antibiotics

• Initiate antibiotics only when acute bacterial sinusitis is confirmed, not for viral rhinosinusitis (common cold) 2, 1
• Start treatment if symptoms persist >7-10 days without improvement, or if severe symptoms (high fever ≥39°C with purulent nasal discharge) are present for 3-4 consecutive days 1, 3
• Watchful waiting without antibiotics is appropriate for uncomplicated cases when follow-up is assured, starting antibiotics only if no improvement by 7 days or worsening at any time 1

First-Line Antibiotic Selection by Clinical Scenario

Standard Maxillary Sinusitis (Most Common)

• Amoxicillin 500 mg twice daily for mild disease or 875 mg twice daily for moderate disease 1
• Amoxicillin-clavulanate 875/125 mg twice daily is preferred if recent antibiotic exposure within past 30 days, severe disease, or high local resistance rates 1
• Treatment duration: 5-10 days (shorter courses have equivalent efficacy with fewer side effects) 1, 4

High-Risk or Complicated Sinusitis

• For frontal, ethmoidal, or sphenoidal sinusitis, use fluoroquinolones (levofloxacin 500 mg daily or moxifloxacin 400 mg daily) due to risk of serious complications 2, 1
• These locations require more aggressive therapy because of potential for meningitis, orbital complications, or cavernous sinus thrombosis 2

Penicillin-Allergic Patients

• Second-generation cephalosporins: cefuroxime-axetil 250-500 mg twice daily 2, 1
• Third-generation cephalosporins: cefpodoxime-proxetil 200 mg twice daily or cefdinir 300 mg twice daily 2, 1
• The risk of cross-reactivity with second- and third-generation cephalosporins in penicillin-allergic patients is negligible 1
• Pristinamycin for true beta-lactam allergy 2
• Do NOT use azithromycin or clarithromycin due to 20-25% resistance rates in S. pneumoniae and H. influenzae 1, 5

Treatment Failure Protocol

• If no improvement after 3-5 days (pediatrics) or 7 days (adults), reassess diagnosis and switch antibiotics 1
• Second-line options include:
  • Amoxicillin-clavulanate 875/125 mg twice daily if not used initially 1
  • Respiratory fluoroquinolones (levofloxacin 500 mg daily or moxifloxacin 400 mg daily) for treatment failures 2, 1
• Consider imaging (CT scan) if not previously performed to confirm diagnosis and rule out complications 1

Adjunctive Therapies

• Intranasal corticosteroids (e.g., fluticasone, mometasone) are recommended as adjunct to antibiotics in both acute and chronic sinusitis 2, 1
• Oral corticosteroids may be used short-term (e.g., dexamethasone 4 mg) for acute hyperalgic sinusitis (severe pain) or marked mucosal edema 1
• Topical decongestants (oxymetazoline) for maximum 3-5 days only to avoid rebound congestion 2, 6
• Oral decongestants and analgesics for symptomatic relief, though evidence for efficacy is limited 2, 7

Pediatric Dosing

• Amoxicillin 45 mg/kg/day in 2 divided doses for mild disease without recent antibiotic use 1
• High-dose amoxicillin 80-90 mg/kg/day in 2 divided doses for areas with high prevalence of resistant S. pneumoniae, or for children <2 years, daycare attendance, or recent antibiotic use 1
• Amoxicillin-clavulanate 80-90 mg/kg/day of amoxicillin component with 6.4 mg/kg/day clavulanate in 2 divided doses for high-risk children 1
• Cefpodoxime-proxetil 8 mg/kg/day in 2 doses for penicillin-allergic children 1
• Treatment duration: 10-14 days until symptom-free for 7 days 1

Critical Pitfalls to Avoid

• Never use macrolides (azithromycin, clarithromycin) as first-line therapy due to high resistance rates 1, 5, 8
• Do not reserve fluoroquinolones for routine first-line use—save them for complicated sinusitis or treatment failures to prevent resistance 2, 1
• Ensure adequate treatment duration (minimum 5-7 days, typically 7-10 days) to prevent relapse 2, 1
• Do not use topical decongestants beyond 3-5 days to prevent rhinitis medicamentosa 2, 6
• Complete the full antibiotic course even after symptoms improve to prevent relapse 1
• Do not treat viral upper respiratory infections with antibiotics—most "sinus infections" in the first 7 days are viral 1, 9

When to Refer or Hospitalize

• Clinical signs of complications require immediate hospitalization: meningeal signs, exophthalmos, palpebral edema, ocular mobility disorders, severe pain preventing sleep 2
• Refer to ENT specialist for recurrent sinusitis (≥3 episodes/year), refractory cases despite appropriate antibiotics, or need for endoscopic sinus surgery 1
• Evaluate for underlying conditions in refractory cases: allergic rhinitis (IgE testing), immunodeficiency (quantitative immunoglobulins), anatomic abnormalities (CT imaging), or other conditions like vasculitis or cystic fibrosis 6