What is the first-line prescription for a sinus infection?

First-Line Prescription for Sinus Infection

Amoxicillin-clavulanate 875 mg/125 mg twice daily for 7-10 days is the preferred first-line antibiotic for acute bacterial sinusitis in adults. 1, 2

When to Prescribe Antibiotics

Antibiotics are indicated when acute bacterial sinusitis is established with:

• Unilateral or bilateral infraorbital pain that worsens when bending forward 3
• Purulent rhinorrhea (anterior and/or posterior, often unilateral) 3
• Symptoms persisting >10 days without improvement, or severe symptoms (high fever with purulent discharge for 3-4 consecutive days), or worsening after initial improvement 1

Do not prescribe antibiotics when nasal symptoms remain diffuse, bilateral, and moderate with serous discharge in an epidemic context—use symptomatic treatment first 3

First-Line Antibiotic Selection

Standard First-Line Choice

• Amoxicillin-clavulanate 875 mg/125 mg twice daily is preferred due to increasing prevalence of beta-lactamase-producing organisms (H. influenzae and M. catarrhalis) 1, 2
• Plain amoxicillin 500 mg twice daily (mild infections) or 875 mg twice daily (moderate infections) remains acceptable for uncomplicated cases without recent antibiotic exposure 1, 2

Treatment Duration

• 7-10 days until symptom-free for 7 days (typically 10-14 days total) 1, 2
• Some cephalosporins (cefuroxime-axetil, cefpodoxime-proxetil) are effective in 5-day courses 3, 1

Penicillin-Allergic Patients

For documented penicillin allergy:

• Second-generation cephalosporins: cefuroxime-axetil 3, 1
• Third-generation cephalosporins: cefpodoxime-proxetil, cefdinir, or cefotiam-hexetil 3, 1
• Pristinamycin for beta-lactam allergy 3

Critical pitfall: Azithromycin and other macrolides should NOT be used as first-line therapy due to 20-25% resistance rates in S. pneumoniae and H. influenzae 1, 4

Treatment Based on Anatomic Location

Maxillary Sinusitis (Most Common)

• Use standard first-line antibiotics listed above 3, 1
• Symptoms: infraorbital pain worsening with head bent forward, pulsatile, peaking evening/night 3

Frontal, Ethmoidal, or Sphenoidal Sinusitis

• Reserve fluoroquinolones (levofloxacin 500-750 mg daily or moxifloxacin 400 mg daily) due to higher complication risk 3, 1
• These sites require more aggressive treatment because of potential for serious complications (meningitis, orbital complications) 3

Second-Line Treatment for Failure

If no improvement after 3-5 days:

• Switch to high-dose amoxicillin-clavulanate (if not already used) 1, 2
• Consider respiratory fluoroquinolones: levofloxacin 750 mg daily for 5 days or 500 mg daily for 10 days; moxifloxacin 400 mg daily for 10 days 1, 5
• Fluoroquinolones provide 90-92% clinical efficacy and 100% eradication of S. pneumoniae, including multi-drug resistant strains 1, 5

Adjunctive Therapies

• Intranasal corticosteroids as adjunct to antibiotics 1, 2
• Short-term oral corticosteroids (e.g., dexamethasone 4 mg) for acute hyperalgic sinusitis (severe pain) or marked mucosal edema 1, 2
• Adequate hydration, analgesics, warm facial packs, sleeping with head elevated 1

Important caveat: Systemic corticosteroids should never be used as monotherapy—antibiotics are necessary to treat the underlying infection 1

Critical Pitfalls to Avoid

• Inadequate treatment duration leads to relapse—complete the full 7-10 day course even after symptoms improve 1
• Do not use fluoroquinolones as routine first-line therapy—reserve for complicated sinusitis or treatment failure to prevent resistance 3, 1
• Reassess at 3-5 days if no improvement to avoid treatment failure 1, 2
• Topical decongestants should not be used >3 days due to risk of rhinitis medicamentosa 4

Watchful Waiting Option

For uncomplicated acute bacterial sinusitis with assured follow-up, watchful waiting without immediate antibiotics is appropriate, starting antibiotics if no improvement by 7 days or worsening at any time 1