What are the next steps for treating sinusitis after failure of Augmentin (amoxicillin-clavulanate)?

Treatment of Sinusitis After Augmentin Failure

For patients who fail treatment with Augmentin (amoxicillin-clavulanate), respiratory fluoroquinolones (levofloxacin or moxifloxacin) are the recommended next-line therapy due to their high predicted clinical efficacy of 90-92% against resistant pathogens. 1

Assessment of Treatment Failure

• Treatment failure is defined as worsening of symptoms or lack of improvement within 7 days after diagnosis of acute bacterial rhinosinusitis (ABRS) 2
• Failure to improve is characterized by persistent presenting signs or symptoms without reduction by 7 days after diagnosis 2
• Worsening is defined as progression of presenting signs/symptoms or onset of new signs/symptoms 2

Next-Line Antibiotic Options

• First choice: Respiratory fluoroquinolones (levofloxacin or moxifloxacin) for 5-7 days 1

  • Excellent coverage for both S. pneumoniae and H. influenzae, including resistant strains
  • Specifically recommended when patients fail to respond to initial empiric antimicrobial therapy

• Alternative options:

  • High-dose amoxicillin-clavulanate (2g every 12 hours) 2
  • Doxycycline (for adults) 2, 1
  • Combination therapy: Clindamycin plus a third-generation oral cephalosporin (cefixime or cefpodoxime) for patients with non-type I hypersensitivity to penicillin 2, 1

Adjunctive Therapies

• Intranasal corticosteroids: Recommended as an adjunct to antibiotic therapy 2, 1

  • Helps reduce mucosal inflammation
  • Particularly beneficial when there is marked mucosal edema or nasal polyposis

• Short-term oral corticosteroids: May be considered for patients who fail to respond to initial treatment, especially with nasal polyposis or marked mucosal edema 2, 3

• Saline irrigation: Improves sinus drainage and mucociliary clearance 1

Monitoring Response to New Treatment

• Clinical improvement should be expected within 3-5 days of starting appropriate therapy 1
• If symptoms worsen after 48-72 hours or fail to improve after 3-5 days on the new antibiotic, further evaluation is needed 2, 1
• Treatment should continue until the patient has been symptomatically improved to near normal, typically requiring 10-14 days 2

When to Consider Specialist Referral

• If the patient fails to respond to the respiratory fluoroquinolone 1
• For recurrent sinusitis (typically 3 or more episodes per year) 1
• When sinusitis is associated with complications such as orbital or intracranial involvement 1
• To consider obtaining cultures by direct sinus aspiration or endoscopically guided cultures if the patient fails to respond to second-line therapy 1

Potential Causes of Treatment Failure

• Resistant bacterial pathogens not adequately covered by prior antibiotics 1
• Presence of nasal polyps impeding drainage 2, 1
• Non-bacterial causes (fungal, viral, allergic) 1
• Inadequate drainage of sinuses 1
• Noncompliance with medication regimen 1

Important Caveats and Pitfalls

• Avoid using macrolides (azithromycin, clarithromycin) as second-line agents due to their relatively weak activity against penicillin-resistant H. influenzae and S. pneumoniae 1
• Cefixime and ceftibuten have poor activity against S. pneumoniae and should not be used as monotherapy 1
• Be cautious with fluoroquinolones in children due to potential adverse effects on joint development 1, 4
• Consider the possibility of anaerobic pathogens in protracted or severe cases of sinusitis 1

Imaging Considerations

• Imaging studies are not indicated for uncomplicated ABRS but may be appropriate to "rule out" ABRS if the patient does not respond to therapy 2
• Consider a sinus CT scan if symptoms fail to improve after appropriate antibiotic therapy 3