What is the recommended treatment for sinus infections?

Treatment of Acute Bacterial Sinusitis

For most adults with acute bacterial sinusitis, start with amoxicillin-clavulanate 875 mg/125 mg twice daily for 5-10 days, as this provides optimal coverage against resistant organisms including β-lactamase-producing bacteria. 1

Initial Diagnostic Considerations

Before initiating antibiotics, distinguish between viral and bacterial sinusitis:

• Viral rhinosinusitis (the common cold) is the most common cause and does not require antibiotics 2
• Bacterial sinusitis should be suspected when symptoms persist beyond 10 days without improvement, or when severe symptoms (high fever ≥39°C with purulent nasal discharge) occur for 3-4 consecutive days, or when symptoms worsen after initial improvement 3
• Watchful waiting for 7 days without antibiotics is appropriate for uncomplicated cases in adults when follow-up can be assured, starting antibiotics only if no improvement occurs 1

First-Line Antibiotic Selection

Standard Adult Dosing

Amoxicillin-clavulanate is preferred over plain amoxicillin because β-lactamase-producing H. influenzae and M. catarrhalis have become increasingly prevalent, and the clavulanate component provides essential coverage against these organisms 1, 3

• Amoxicillin-clavulanate 875 mg/125 mg twice daily for 5-10 days 1
• Plain amoxicillin 500-875 mg twice daily remains acceptable only for uncomplicated cases without recent antibiotic exposure 1
• Treatment duration: 5-10 days, with most guidelines recommending continuation until symptom-free for 7 days 1
• Shorter 5-7 day courses have comparable efficacy with fewer side effects 1

Pediatric Dosing

• High-dose amoxicillin 80-90 mg/kg/day in 2 divided doses for areas with high prevalence of resistant S. pneumoniae 1
• Amoxicillin-clavulanate 80-90 mg/kg/day of amoxicillin component with 6.4 mg/kg/day clavulanate in 2 divided doses for children with risk factors (age <2 years, daycare attendance, recent antibiotic use) 1

Penicillin-Allergic Patients

Second- and third-generation cephalosporins are the preferred alternatives, as the risk of cross-reactivity in penicillin-allergic patients is negligible 1

Recommended Cephalosporins

• Cefuroxime-axetil (second-generation) 1
• Cefpodoxime-proxetil (third-generation, superior activity against H. influenzae) 1
• Cefdinir (third-generation, excellent coverage) 1
• For pediatric penicillin allergy: cefpodoxime proxetil 8 mg/kg/day in two doses 1

Critical Pitfall to Avoid

Never use azithromycin or other macrolides as first-line therapy due to 20-25% resistance rates among S. pneumoniae and H. influenzae 1

Treatment Failure Protocol

Reassess at 72 hours (pediatrics) or 3-5 days (adults) if no improvement occurs 1

Second-Line Options

When first-line therapy fails or for complicated sinusitis:

• Respiratory fluoroquinolones: Levofloxacin 500-750 mg once daily or moxifloxacin 1, 4
• Fluoroquinolones provide 90-92% predicted clinical efficacy and 100% microbiologic eradication of S. pneumoniae, including multi-drug resistant strains 1
• Reserve fluoroquinolones specifically for treatment failures, complicated sinusitis (frontal, ethmoidal, or sphenoidal involvement), or multi-drug resistant organisms to prevent resistance development 1

Anatomic Location-Based Treatment

Maxillary Sinusitis (Most Common)

• Standard first-line antibiotics (amoxicillin-clavulanate) 1
• Symptoms: unilateral/bilateral infraorbital pain worsening when bending forward, pulsatile, peaking evening/night 1

Frontal, Ethmoidal, or Sphenoidal Sinusitis

• Consider fluoroquinolones (levofloxacin or moxifloxacin) due to potential for serious complications 1

Adjunctive Therapies

Intranasal Corticosteroids

• Recommended as adjunct to antibiotic therapy in both acute and chronic sinusitis 2, 1
• Continue for 3 months when cough disappears with therapy 2

Oral Corticosteroids

• Short-term use (e.g., dexamethasone 4 mg) may be beneficial for acute hyperalgic sinusitis (severe pain) or marked mucosal edema 1
• Should never be used as monotherapy; always combine with appropriate antibiotics 1

Decongestants

• Oxymetazoline hydrochloride for 5 days maximum 2
• No prospective randomized trials prove efficacy of nasal or oral decongestants, but clinical experience supports their use 2

Supportive Measures

• Adequate hydration, analgesics, warm facial packs, sleeping with head elevated 1

Critical Pitfalls to Avoid

1. Inadequate treatment duration leads to relapse - ensure minimum 5 days, typically 7-10 days total 1
2. Overuse of fluoroquinolones promotes resistance - reserve for treatment failures or complicated cases 1
3. Failure to reassess at appropriate intervals - check at 72 hours (pediatrics) or 3-5 days (adults) 1
4. Using macrolides as first-line therapy - resistance rates are too high 1
5. Stopping antibiotics when symptoms improve - complete the full course to prevent relapse 1

When to Refer to Specialist

• Sinusitis refractory to usual antibiotic treatment 1
• Recurrent sinusitis (≥3 episodes per year) 1
• Need to clarify allergic or immunologic basis 1
• Documented chronic sinus infection with anatomic obstruction amenable to endoscopic sinus surgery 2