What is the recommended treatment for a patient with acute sinusitis?

Recommended Treatment for Acute Sinusitis

For adults with acute bacterial sinusitis, amoxicillin-clavulanate 875 mg/125 mg twice daily for 5-10 days is the first-line antibiotic treatment, but watchful waiting without immediate antibiotics is equally appropriate when reliable follow-up can be assured. 1, 2

Confirming the Diagnosis Before Prescribing Antibiotics

Most acute sinusitis (98-99.5%) is viral and resolves spontaneously within 7-10 days without antibiotics. 1, 2 Only prescribe antibiotics when one of three criteria is met:

• Persistent symptoms ≥10 days without improvement 1, 2
• Severe symptoms (fever ≥39°C with purulent nasal discharge) for ≥3-4 consecutive days 1, 2
• "Double sickening" - worsening after initial improvement from a viral upper respiratory infection 1, 2

Do not use mucus color alone to determine antibiotic need, as color reflects neutrophils, not bacteria. 2

First-Line Antibiotic Selection

Amoxicillin-clavulanate 875 mg/125 mg twice daily for 5-10 days is preferred over plain amoxicillin due to increasing prevalence of β-lactamase-producing organisms (Haemophilus influenzae and Moraxella catarrhalis). 1, 2 This provides 90-92% predicted clinical efficacy against major pathogens. 2

When to Use High-Dose Amoxicillin-Clavulanate

Use high-dose amoxicillin-clavulanate (2 g amoxicillin/125 mg clavulanate twice daily) for patients with: 1, 2

• Recent antibiotic use within the past 4-6 weeks 1, 2
• Age >65 years 2
• Moderate-to-severe symptoms 2
• Comorbid conditions or immunocompromised state 2

Treatment Duration

Adults: 5-7 days for uncomplicated cases, with most guidelines recommending treatment until symptom-free for 7 days (typically 10-14 days total). 1, 2 Recent evidence supports shorter 5-7 day courses with comparable efficacy and fewer adverse effects. 2, 3

Children: 10-14 days is still recommended despite adult data supporting shorter courses. 1, 2

Penicillin-Allergic Patients

For non-severe (non-Type I) penicillin allergy, use second- or third-generation cephalosporins: 1, 2

• Cefuroxime-axetil 1, 2
• Cefpodoxime-proxetil 1, 2
• Cefdinir 1, 2

The risk of cross-reactivity between penicillins and second/third-generation cephalosporins is negligible for non-Type I reactions. 2

For severe penicillin allergy (anaphylaxis), use respiratory fluoroquinolones: 2

• Levofloxacin 500 mg once daily for 10-14 days 2, 4
• Moxifloxacin 400 mg once daily for 10 days 2

Essential Adjunctive Therapies

All patients should receive adjunctive therapies regardless of antibiotic choice: 1, 2

• Intranasal corticosteroids (mometasone, fluticasone, or budesonide) twice daily - strongly recommended to reduce mucosal inflammation and improve symptom resolution 1, 2
• Saline nasal irrigation - provides symptomatic relief and removes mucus 1, 2
• Analgesics (acetaminophen or NSAIDs) for pain and fever 1, 2
• Adequate hydration 1

Decongestants and antihistamines are not recommended as adjunctive treatment. 1

When to Reassess and Switch Antibiotics

Critical reassessment timepoints: 1, 2

• Day 3-5: If no improvement, switch to second-line therapy 1, 2
• Day 7: If symptoms persist or worsen, reconfirm diagnosis and consider complications 2

Second-Line Treatment Options

If no improvement after 3-5 days of amoxicillin-clavulanate, switch to: 1, 2

• Respiratory fluoroquinolones (levofloxacin 500-750 mg once daily or moxifloxacin 400 mg once daily) for 10-14 days - provides 90-92% predicted clinical efficacy 2, 4
• High-dose amoxicillin-clavulanate (2 g/125 mg twice daily) if not already used 2
• Third-generation cephalosporins (cefpodoxime or cefdinir) for 10 days 2

Pediatric Dosing

Standard therapy: Amoxicillin 45 mg/kg/day in 2 divided doses 1, 2

High-dose therapy (for high-risk children): Amoxicillin 80-90 mg/kg/day in 2 divided doses 1, 2

High-risk children include those with: 1, 2

• Age <2 years
• Daycare attendance
• Recent antibiotic use within past 4-6 weeks
• High local resistance rates

For treatment failure at 72 hours: Switch to high-dose amoxicillin-clavulanate (80-90 mg/kg/day of amoxicillin component with 6.4 mg/kg/day clavulanate in 2 divided doses). 1, 2

When to Refer to a Specialist

Refer to otolaryngology or infectious disease if: 1, 2

• No improvement after 7 days of appropriate second-line therapy 2
• Worsening symptoms at any time 1, 2
• Suspected complications (orbital cellulitis, meningitis, abscess formation) 1, 2
• Recurrent sinusitis (≥3 episodes per year) 1, 2
• Seriously ill or immunocompromised patients 1

Critical Pitfalls to Avoid

Never use these antibiotics as first-line therapy: 1, 2

• Azithromycin or macrolides - 20-25% resistance rates for both S. pneumoniae and H. influenzae 1, 2
• Trimethoprim-sulfamethoxazole - 50% resistance rate for S. pneumoniae 2
• First-generation cephalosporins (cephalexin) - inadequate H. influenzae coverage 2
• Clindamycin as monotherapy - lacks activity against H. influenzae and M. catarrhalis 2

Do not prescribe antibiotics for symptoms <10 days unless severe features are present (fever ≥39°C with purulent discharge for ≥3 consecutive days). 1, 2

Reserve fluoroquinolones for treatment failures or documented severe β-lactam allergies to prevent resistance development. 1, 2

Ensure adequate treatment duration - minimum 5 days for adults and 10 days for children to prevent relapse. 1, 2