What antibiotics are prescribed for chronic sinusitis-related rhinitis?

Antibiotic Selection for Chronic Sinusitis-Related Rhinitis

For chronic rhinosinusitis, antibiotics are NOT routinely recommended as first-line therapy, but when bacterial infection is confirmed or strongly suspected, amoxicillin-clavulanate 875/125 mg twice daily for 14 days is the preferred choice. 1

Understanding the Clinical Context

Chronic rhinosinusitis (CRS) differs fundamentally from acute bacterial sinusitis—it represents persistent mucosal inflammation lasting ≥12 weeks rather than acute bacterial infection. 1 The role of antibiotics in CRS is controversial and limited compared to acute disease.

When Antibiotics Are Appropriate in CRS

Antibiotics should only be prescribed when:

• Purulent nasal discharge is documented on endoscopy with confirmed bacterial infection via sinus puncture 1
• Acute exacerbation of CRS occurs (worsening symptoms with fever, purulent discharge lasting ≤4 weeks in a patient with underlying CRS) 1
• CT or endoscopy confirms significant mucosal disease with clinical signs of bacterial superinfection 1

First-Line Antibiotic Choices

Amoxicillin-clavulanate remains the gold standard:

• Dosing: 875/125 mg twice daily for 14 days 1
• Rationale: Provides coverage against β-lactamase-producing H. influenzae and M. catarrhalis, which are increasingly prevalent 1
• Evidence: Multiple RCTs demonstrate comparable or superior efficacy to cefuroxime, with significantly faster symptom improvement at days 3-5 (81% vs 56%, p=0.0137) 1

Alternative first-line options:

• Cefuroxime 500 mg twice daily for 14 days - comparable clinical cure rates (88-95%) but slower initial response 1
• Ciprofloxacin 500 mg twice daily for 9 days - similar clinical cure rates (58.6% vs 51.2% for amoxicillin-clavulanate) with better sustained bacteriologic clearance at 40 days (83.3% vs 67.6%, p=0.043) 1

For Penicillin-Allergic Patients

Second-generation cephalosporins are preferred:

• Cefuroxime-axetil - documented safety in non-severe penicillin allergy 2
• Third-generation options: Cefpodoxime-proxetil or cefdinir provide superior H. influenzae coverage 2

Reserve fluoroquinolones for:

• Severe beta-lactam allergy 2
• Treatment failure after 7-10 days 2
• Frontal, ethmoidal, or sphenoidal sinusitis (higher complication risk) 2

Macrolide Therapy: Anti-Inflammatory Role

Clarithromycin has a distinct role in CRS without nasal polyps:

• High-dose regimen: 500 mg twice daily for 7 days, then 250 mg twice daily for 7 days showed significant improvement in nasal symptoms, SNOT-20 scores, and endoscopic findings compared to low-dose (250 mg daily) 1
• Mechanism: Reduces IL-8 and IL-5 levels in nasal secretions, suggesting anti-inflammatory rather than purely antibacterial effects 1
• Important caveat: Standard-dose clarithromycin (500 mg daily for 3 weeks) showed no significant difference from amoxicillin-clavulanate for symptom improvement 1

Doxycycline 100 mg daily for 20 days:

• Demonstrated modest reduction in nasal polyp size and postnasal drip in CRS with nasal polyps 2
• Reduces myeloperoxidase and MMP-9 levels, indicating anti-inflammatory effects 1

Critical Treatment Pitfalls

Avoid these common errors:

• Do NOT use azithromycin - resistance rates exceed 20-25% for both S. pneumoniae and H. influenzae 2
• Do NOT use first-generation cephalosporins (cephalexin) - inadequate H. influenzae coverage 2
• Do NOT prescribe antibiotics for viral rhinosinusitis lasting <10 days without severe symptoms 1, 2
• Reassess at 3-5 days - if no improvement, switch antibiotics or reconsider diagnosis 2

Adjunctive Therapy is Essential

Intranasal corticosteroids are MORE important than antibiotics in CRS:

• Mometasone, fluticasone, or budesonide twice daily reduces mucosal inflammation 2, 3
• Should be continued long-term, even after antibiotics are stopped 3

Supportive measures:

• Saline nasal irrigation for symptomatic relief 2
• Adequate hydration and analgesics 2
• Oral decongestants (pseudoephedrine) for short-term use 3

When to Refer to Otolaryngology

Refer if:

• No improvement after two courses of appropriate antibiotics 2
• Recurrent sinusitis (≥3 episodes per year) 2
• Suspected complications (orbital cellulitis, meningitis) 2
• Consideration for functional endoscopic sinus surgery 3

Treatment Duration Matters

Standard duration is 14 days for CRS - shorter courses (7-10 days) are appropriate for acute bacterial sinusitis but insufficient for chronic disease. 1 Continue treatment until symptom-free for 7 days to prevent relapse. 2