What is the recommended treatment for bacterial sinusitis with Augmentin (amoxicillin-clavulanate)?

Augmentin for Bacterial Sinusitis

Amoxicillin-clavulanate (Augmentin) 875/125 mg twice daily for 10-14 days is the recommended first-line treatment for acute bacterial sinusitis in adults, particularly when there is moderate-to-severe illness, recent antibiotic use, or high local prevalence of β-lactamase-producing organisms. 1

When to Prescribe Augmentin

Antibiotics should be prescribed only when acute bacterial sinusitis is diagnosed based on one of three clinical presentations: 2, 3

• Persistent symptoms: Nasal discharge or daytime cough lasting >10 days without improvement 2
• Worsening symptoms: Initial improvement followed by worsening or new nasal discharge, cough, or fever 2
• Severe onset: Fever ≥102.2°F (39°C) with purulent nasal discharge for ≥3 consecutive days 2

Standard Dosing Regimen

The standard adult dose is amoxicillin 875 mg/clavulanate 125 mg twice daily for 10-14 days. 1 Some experts recommend continuing treatment until symptom-free plus an additional 7 days. 1, 4

For patients requiring initial parenteral therapy (vomiting, unable to take oral medications), ceftriaxone 50 mg/kg IV/IM once can be given, then switched to oral therapy after clinical improvement. 2

High-Dose Formulations: Limited Benefit

High-dose amoxicillin-clavulanate (1750-2000 mg amoxicillin twice daily) should be considered for: 1, 3

• Moderate-to-severe illness
• Recent antibiotic use (within 4-6 weeks)
• High prevalence of resistant S. pneumoniae
• Treatment failure with standard-dose amoxicillin

However, recent high-quality evidence shows high-dose formulations provide no significant advantage over standard dosing. A 2021 randomized trial found no difference in improvement rates at day 3 between high-dose and standard-dose regimens (36.4% vs 44.3%, P=0.35). 5 A 2018 trial showed mixed results, with immediate-release high-dose showing modest benefit (18% improvement, P=0.04) but extended-release showing none, while severe diarrhea increased significantly (15.8% vs 4.8%, P=0.048). 6

Monitoring Treatment Response

Evaluate clinical response after 72 hours (3 days). 1, 3 If no improvement or worsening occurs: 2, 3

• Consider switching to alternative antibiotics (respiratory fluoroquinolones, clindamycin plus cefixime)
• Reevaluate the diagnosis
• Consider imaging if complications suspected

Penicillin Allergy Alternatives

For patients with penicillin hypersensitivity: 2, 3

• Non-type 1 allergies: Cefdinir, cefuroxime, or cefpodoxime 2
• Type 1 allergies (adults): Respiratory fluoroquinolones (levofloxacin, moxifloxacin) 3

Do NOT use azithromycin or trimethoprim-sulfamethoxazole due to high resistance rates in S. pneumoniae and H. influenzae (20-25% bacteriologic failure rates). 2, 3 Despite one older study showing azithromycin efficacy 7, current surveillance data demonstrate significant resistance, making it unsuitable for empiric treatment. 3

Common Pitfalls to Avoid

• Treating viral upper respiratory infections with antibiotics: This is inappropriate and drives resistance. 1, 3 Only prescribe when bacterial sinusitis criteria are met.
• Incomplete antibiotic courses: Not completing the full 10-14 day course can lead to treatment failure and relapse. 1
• Using imaging routinely: Plain radiography, CT, or MRI should NOT be performed to differentiate bacterial from viral sinusitis. 2 Reserve contrast-enhanced CT/MRI only for suspected orbital or CNS complications (proptosis, impaired extraocular movements, severe headache, altered mental status). 2
• Prescribing high-dose formulations routinely: Standard dosing is equally effective with fewer gastrointestinal side effects. 5, 6

Complications Requiring Urgent Intervention

Suspect complications and obtain immediate contrast-enhanced CT if: 2

• Orbital involvement: Periorbital swelling with >50% eyelid closure, proptosis, impaired extraocular movements, or visual changes
• CNS involvement: Severe headache, altered mental status, seizures, focal neurologic findings, or Pott's puffy tumor

For complicated sinusitis, hospitalize and initiate IV vancomycin (to cover methicillin-resistant S. pneumoniae) with urgent otolaryngology, ophthalmology, and infectious disease consultation. 2