What is the recommended treatment for sinusitis?

Treatment of Sinusitis

For acute bacterial sinusitis in adults, amoxicillin-clavulanate 875 mg/125 mg twice daily for 5-10 days is the preferred first-line antibiotic, with intranasal corticosteroids as adjunctive therapy. 1

Distinguishing Acute vs. Chronic Sinusitis

• Acute sinusitis is defined as symptoms lasting less than 4 weeks, while chronic sinusitis persists beyond this timeframe 1
• Antibiotics are indicated for acute bacterial sinusitis but should only be used for acute bacterial exacerbations superimposed on chronic sinusitis, not as routine maintenance therapy 2

First-Line Antibiotic Treatment for Acute Bacterial Sinusitis

Standard Therapy

• Amoxicillin-clavulanate 875 mg/125 mg twice daily is the preferred first-line choice for most adults with acute bacterial sinusitis 1
• Plain amoxicillin 500 mg twice daily (mild disease) or 875 mg twice daily (moderate disease) remains acceptable for uncomplicated cases without recent antibiotic exposure 1
• Treatment duration is 5-10 days, with most guidelines recommending treatment until symptom-free for 7 days (typically 10-14 days total) 1
• Shorter 5-7 day courses have comparable efficacy with fewer side effects 1

Penicillin-Allergic Patients

• Second-generation cephalosporins (cefuroxime-axetil) or third-generation cephalosporins (cefpodoxime-proxetil, cefdinir) are recommended alternatives 1
• The risk of serious allergic reactions to second- and third-generation cephalosporins in penicillin-allergic patients is negligible 1
• Azithromycin should NOT be used due to 20-25% resistance rates in Streptococcus pneumoniae and Haemophilus influenzae 1, 2

Treatment Based on Anatomic Location

Maxillary Sinusitis (Most Common)

• Use standard first-line antibiotics (amoxicillin or amoxicillin-clavulanate) 1
• Clinical features include unilateral/bilateral infraorbital pain worsening when bending forward, pulsatile, peaking evening/night 1

Frontal, Ethmoidal, or Sphenoidal Sinusitis

• Reserve fluoroquinolones (levofloxacin 500-750 mg daily or moxifloxacin 400 mg daily) for these locations due to potential for serious complications 1
• These sites require more aggressive coverage given proximity to critical structures 1

Second-Line Treatment for Treatment Failure

• If no improvement after 3-5 days, reassess the diagnosis and switch to a different antibiotic 1
• Amoxicillin-clavulanate provides better coverage against resistant bacteria and should be used if initial amoxicillin fails 1
• Respiratory fluoroquinolones (levofloxacin or moxifloxacin) are reserved for treatment failures, complicated sinusitis, or multi-drug resistant S. pneumoniae 1
• Fluoroquinolones demonstrate 90-92% predicted clinical efficacy with 100% microbiologic eradication of S. pneumoniae 1

Adjunctive Therapies

Intranasal Corticosteroids

• Intranasal corticosteroids are recommended as adjunct to antibiotic therapy in both acute and chronic sinusitis 1
• These promote drainage and reduce inflammation 1

Oral Corticosteroids

• Short-term oral corticosteroids (e.g., dexamethasone 4 mg) may be reasonable for acute hyperalgic sinusitis (severe pain) or marked mucosal edema 1
• Should NOT be used as monotherapy—antibiotics remain necessary for bacterial infection 1

Decongestants

• Oral or topical decongestants may provide symptomatic relief 2
• Topical decongestants (oxymetazoline) should not exceed 3-5 days to avoid rebound congestion 2

Supportive Measures

• Adequate hydration, analgesics, warm facial packs, and sleeping with head elevated 1

Pediatric Dosing

• Amoxicillin 45 mg/kg/day in 2 divided doses for standard therapy 1
• High-dose amoxicillin 80-90 mg/kg/day in 2 divided doses for areas with high prevalence of resistant S. pneumoniae or children with risk factors (age <2 years, daycare attendance, recent antibiotic use) 1
• Amoxicillin-clavulanate 80-90 mg/kg/day (amoxicillin component) with 6.4 mg/kg/day clavulanate in 2 divided doses for children with risk factors 1
• For penicillin-allergic children, cefpodoxime proxetil 8 mg/kg/day in two doses 1
• Treatment duration for acute otitis media is 10 days 3

Watchful Waiting Option

• For adults with uncomplicated acute bacterial sinusitis, watchful waiting without antibiotics is appropriate when follow-up can be assured 1
• Start antibiotics if no improvement by 7 days or worsening at any time 1

Chronic Sinusitis Management

• Antibiotics should only be used for acute bacterial exacerbations, not as routine maintenance therapy 2
• When acute exacerbation is suspected, use antibiotics effective against H. influenzae, mouth anaerobes, and S. pneumoniae 2
• Minimum 3-week course for acute exacerbations of chronic sinusitis 2
• First-line options: amoxicillin 500 mg twice daily or amoxicillin-clavulanate 500-875 mg twice daily 2
• Antibiotic prophylaxis is NOT recommended for chronic sinusitis 2

Refractory Cases: When to Investigate Further

• For recurrent sinusitis (≥3 episodes per year), evaluate for: 1, 2
  • Allergic rhinitis: Test for IgE sensitization to inhalant allergens 2
  • Immunodeficiency: Check quantitative IgG, IgA, IgM levels and specific antibody responses 2
  • Anatomic abnormalities: Consider CT imaging if not already performed 2
  • Other conditions: Vasculitides, granulomatous diseases, cystic fibrosis 2

Critical Pitfalls to Avoid

• Do NOT use azithromycin or other macrolides as first-line therapy due to high resistance rates 1, 2
• Do NOT substitute two 250 mg/125 mg tablets for one 500 mg/125 mg tablet of amoxicillin-clavulanate—they contain different amounts of clavulanic acid 3
• Ensure adequate treatment duration (minimum 5 days, typically 7-10 days) to prevent relapse 1
• Do NOT use fluoroquinolones as routine first-line therapy—reserve for complicated cases or treatment failures to prevent resistance 1
• Complete the full course of antibiotics even after symptoms improve to prevent relapse 1
• Do NOT treat viral upper respiratory infections with antibiotics 2
• Reassess at 3 days (pediatrics) or 7 days (adults) if no improvement to avoid treatment failure 1