Antibiotics for Sinusitis: When They're Needed, Which to Choose, and Stewardship Principles

Most Sinusitis Is Viral — Antibiotics Are Overprescribed

Acute bacterial rhinosinusitis (ABRS) complicates only 0.5–2% of viral URIs. Guidelines (IDSA, AAO-HNS) restrict antibiotics to confirmed or highly likely bacterial cases. Here's how to diagnose, treat, and steward responsibly.

Diagnosing ABRS: Clinical Criteria (Antibiotics Warranted If ≥1)

• Persistent symptoms ≥10 days without improvement.
• Severe onset: High fever (≥39°C/102°F) + purulent nasal discharge/facial pain ≥3–4 consecutive days.
• Worsening ("double sickening"): URI improving, then new fever/pain/discharge.

Imaging (CT) NOT routine; reserved for complications or diagnostic uncertainty.

First-Line Agents

• Amoxicillin-clavulanate (Augmentin): 500/125 mg TID or 875/125 mg BID × 5–7 days (adults). Covers β-lactamase+ H. influenzae, M. catarrhalis. Pediatric: 90 mg/kg/day amoxicillin component divided BID.
• Doxycycline: Alternative for penicillin-allergic (non-type I); covers atypicals.
• Respiratory fluoroquinolones (levofloxacin, moxifloxacin): RESERVE for penicillin-allergic with comorbidities or failure; black box warnings (tendinitis, neuropathy, aortic).

Alternative / Second-Line

• Cefuroxime axetil, cefpodoxime, cefdinir (2nd/3rd gen cephalosporins) — if non-severe penicillin allergy.
• Clindamycin + 3rd gen cephalosporin — if anaerobic concern (dental source).
• Azithromycin: NOT recommended for ABRS (poor H. influenzae coverage, high resistance).

Duration

• 5–7 days for uncomplicated ABRS (IDSA 2012); shorter courses non-inferior to 10 days.
• Extend if slow response.

Adjunctive Symptomatic Therapy (For ALL Sinusitis)

• Intranasal corticosteroids (INS) — reduce inflammation, improve penetration.
• Saline irrigation — mechanical clearance.
• Decongestants (oral/nasal) — short-term only (≤3 days nasal to avoid rebound).
• Analgesics (acetaminophen/NSAID).

Antibiotic Stewardship Principles

• Do NOT treat viral URI with antibiotics.
• Use narrowest spectrum effective agent.
• Shortest effective duration.
• Reassess at 48–72h; switch if no improvement (consider resistance, wrong diagnosis, complication).
• Document indication, agent, duration, plan.

Complications Requiring URGENT Attention

• Orbital: Periorbital edema, proptosis, ophthalmoplegia, vision change → orbital cellulitis/abscess (EMERGENCY).
• Intracranial: Severe headache, altered mental status, focal deficits → meningitis, brain abscess, cavernous sinus thrombosis.
• Osteomyelitis (Pott's puffy tumor — frontal bone).

Bottom line: Most sinusitis is viral. Reserve antibiotics for clinical criteria meeting ABRS. First-line: amoxicillin-clavulanate 5–7 days. Adjunct INS + saline. Stewardship protects microbiome and combats resistance.