A 32-year-old man presents with a 10-day history of nasal congestion, purulent nasal discharge, facial pain, and fever. Nasal endoscopy shows purulent discharge from the middle meatus. CT paranasal sinuses confirms acute maxillary sinusitis. What is the drug of choice for empirical treatment?

Explanation

## First-Line Antibiotic for Acute Bacterial Sinusitis **Key Point:** Amoxicillin-clavulanate is the preferred first-line empirical antibiotic for acute bacterial sinusitis in most guidelines, including EPOS (European Position on Rhinosinusitis) and American Academy of Otolaryngology. ### Rationale for Amoxicillin-Clavulanate **High-Yield:** The addition of clavulanate overcomes β-lactamase resistance produced by common pathogens: - *Streptococcus pneumoniae* - *Haemophilus influenzae* (non-typeable) - *Moraxella catarrhalis* These three organisms account for >90% of acute bacterial sinusitis cases. ### Dosing and Duration - **Dose:** 500 mg amoxicillin + 125 mg clavulanate, three times daily - **Duration:** 5–7 days (shorter courses are increasingly supported) - **Route:** Oral (adequate sinus penetration) ### When to Consider Alternatives | Scenario | Alternative | |----------|-------------| | Penicillin allergy (non-severe) | Cefuroxime axetil or cephalosporin | | Severe penicillin allergy (anaphylaxis) | Fluoroquinolone (levofloxacin) | | Treatment failure after 3–5 days | Fluoroquinolone or high-dose amoxicillin-clavulanate | | Immunocompromised host | Broader coverage; consider imaging | **Clinical Pearl:** Acute sinusitis is often viral; antibiotics are reserved for bacterial infection confirmed by purulent nasal discharge, fever, and imaging. Supportive care (saline irrigation, decongestants, NSAIDs) is first-line for viral rhinosinusitis. **Mnemonic:** **SHIP** — *Sinusitis, Haemophilus, Influenzae, Pneumococcus* — the three pathogens covered by amoxicillin-clavulanate. [cite:Park 26e Ch 4]