What are the recommended antibiotics for chronic sinusitis?

Antibiotics for Chronic Sinusitis

Antibiotics should NOT be routinely prescribed for chronic rhinosinusitis (CRS) and should only be used when significant purulent nasal discharge is present on examination, as chronic sinusitis is primarily an inflammatory condition rather than an infectious disease. 1

Primary Treatment Approach

Intranasal corticosteroids and saline irrigation are the cornerstones of chronic sinusitis management, not antibiotics. 1, 2

• Intranasal corticosteroids (such as mometasone furoate or fluticasone propionate) should be the first-line therapeutic intervention due to their anti-inflammatory effects and documented efficacy 3, 4
• Saline nasal irrigation facilitates mechanical removal of mucus and prevents crusting of secretions 1, 2
• These therapies directly address the underlying inflammatory pathophysiology of CRS 1

When Antibiotics May Be Considered

Clinical Criteria for Antibiotic Use

Only prescribe antibiotics when purulent nasal discharge (anterior, posterior, or both) is present on direct examination. 1

• The absence of purulent discharge on examination is a strong contraindication to antibiotic therapy 1
• CRS is mediated by various immunopathologic pathways and is not necessarily associated with microbial infections 1
• The role of bacteria in perpetuating inflammation in CRS remains uncertain 1

Specific Antibiotic Recommendations (When Indicated)

If antibiotics are prescribed for documented purulent exacerbations, amoxicillin-clavulanate 875/125 mg twice daily for 10-14 days is the appropriate choice. 3

• Treatment duration should be 10-14 days or until symptom-free for 7 days 1, 3
• Antibiotics should target respiratory anaerobes, viridans streptococci, S. pneumoniae, H. influenzae, and M. catarrhalis 1
• For penicillin-allergic patients, alternatives include second-generation cephalosporins (e.g., cefuroxime), macrolides, or fluoroquinolones 1

Macrolide Antibiotics: Limited Role

Long-term macrolide therapy (3 months) may provide modest benefit in select CRS patients without polyps, but evidence is limited. 1, 5

• Moderate quality evidence shows a 0.5-point improvement on a 5-point quality of life scale after 3 months of macrolide therapy in adults with CRS without polyps 5
• This benefit disappears 3 months after stopping treatment 5
• Macrolides may work through anti-inflammatory and immunomodulatory properties rather than antimicrobial effects 1
• Consider macrolides only in patients with low IgE levels who have failed standard therapy 6

Evidence Quality and Limitations

The evidence supporting antibiotic use in chronic sinusitis is notably poor. 1, 7, 6

• Multiple systematic reviews indicate data are limited in quantity and quality 1
• European guidelines (EPOS 2020) show amoxicillin-clavulanate demonstrated no statistically significant differences compared to other treatments in chronic rhinosinusitis without polyps 3
• Conservative therapy with antibiotics alone is successful in only one-third of chronic sinusitis cases 1
• There is no high-level experimental evidence to support routine oral antibiotic use in CRS management 6

Critical Pitfalls to Avoid

Overuse of antibiotics should be avoided unless there is clear evidence of bacterial infection with purulent discharge. 1, 2

• Chronic sinusitis is fundamentally different from acute bacterial rhinosinusitis, which does respond to antibiotics 1
• Indiscriminate antibiotic use is associated with limited efficacy and high potential for side effects 1
• Surgical procedures to facilitate sinus drainage are the mainstay of treatment for chronic sinusitis, not antibiotics 1

Alternative Considerations

Before prescribing antibiotics, confirm the diagnosis with objective documentation of sinonasal inflammation using anterior rhinoscopy, nasal endoscopy, or CT scan. 1

• Assess for modifying chronic conditions including asthma, cystic fibrosis, immunocompromised state, and ciliary dyskinesia 1
• Evaluate for underlying allergic rhinitis, anatomic abnormalities, or immunodeficiency if symptoms are recurrent 3
• Consider short-term oral corticosteroids for marked mucosal edema or treatment failure before adding antibiotics 1, 3
• Rule out odontogenic sources with CT scan, as these require dental surgery rather than antibiotics 6