What antibiotic is recommended for treating sinusitis and otitis media?

Antibiotic Treatment for Sinusitis and Otitis Media

For both acute bacterial sinusitis and acute otitis media, amoxicillin-clavulanate is the preferred first-line antibiotic, with high-dose amoxicillin as an acceptable alternative in uncomplicated cases without recent antibiotic exposure. 1, 2

First-Line Treatment Recommendations

For Adults with Sinusitis

Mild disease without recent antibiotic use (past 4-6 weeks):

• Amoxicillin-clavulanate (1.75-4 g/250 mg per day) is preferred 1, 2
• High-dose amoxicillin (1.5-4 g/day) is acceptable for uncomplicated cases 1
• Alternative cephalosporins: cefpodoxime proxetil, cefuroxime axetil, or cefdinir 1

Moderate disease OR recent antibiotic exposure:

• High-dose amoxicillin-clavulanate (4 g/250 mg per day) is strongly recommended 1, 2
• Respiratory fluoroquinolones (levofloxacin, moxifloxacin) are alternatives but should be reserved to avoid promoting resistance 1

For Children with Sinusitis

Mild disease without recent antibiotic use:

• High-dose amoxicillin-clavulanate (90 mg/6.4 mg per kg per day) is first-line 1
• High-dose amoxicillin (90 mg/kg per day) for uncomplicated cases 1
• Alternative cephalosporins: cefdinir (preferred for palatability), cefpodoxime proxetil, or cefuroxime axetil 1

Moderate disease OR recent antibiotic exposure:

• High-dose amoxicillin-clavulanate (90 mg/6.4 mg per kg per day) is mandatory 1

For Acute Otitis Media

First-choice for all ages:

• Amoxicillin is the WHO-recommended first-line agent 1
• Amoxicillin-clavulanate is the second-choice option 1
• Standard amoxicillin dosing demonstrated 87% cure rates in pediatric otitis media trials 3

Treatment Duration

• Sinusitis: 7-10 days is standard, though some experts recommend continuing until symptom-free plus an additional 7 days 2, 4
• Otitis media: 10 days is the established duration 3
• Reassess at 72 hours; if no improvement, switch antibiotics 1, 4

Penicillin-Allergic Patients

For non-severe (Type IV) reactions:

• Second-generation cephalosporins (cefuroxime axetil) or third-generation (cefpodoxime, cefdinir) are safe alternatives 1, 2
• Cefdinir is preferred in children due to better acceptance 1

For severe Type I hypersensitivity:

• TMP-SMX, doxycycline, or macrolides (azithromycin, clarithromycin) can be used, but expect 20-25% bacteriologic failure rates 1
• Clindamycin covers S. pneumoniae well (~90% susceptibility) but has no activity against H. influenzae or M. catarrhalis 1

High-Risk Situations Requiring Aggressive Therapy

Use high-dose amoxicillin-clavulanate when:

• Recent antibiotic use within 4-6 weeks 1
• Daycare attendance (children) 1
• Age <2 years with bilateral otitis media 1
• Immunodeficiency or frequent antibiotic exposure 1
• Geographic areas with high penicillin-resistant S. pneumoniae prevalence 1

The rationale is that these factors increase risk for drug-resistant S. pneumoniae (DRSP), β-lactamase-producing H. influenzae, and M. catarrhalis 1.

Switch Therapy at 72 Hours

If no improvement after 3 days:

• If started on amoxicillin alone → switch to high-dose amoxicillin-clavulanate 1, 4
• If started on amoxicillin-clavulanate → switch to respiratory fluoroquinolone OR ceftriaxone (1 g/day IM/IV for 5 days in adults; 50 mg/kg/day in children) 1
• Consider combination therapy: high-dose amoxicillin or clindamycin PLUS cefixime 1

Critical Pitfalls to Avoid

Do not use fluoroquinolones as first-line therapy - they should be reserved for treatment failures or penicillin-allergic patients to prevent resistance development, particularly in gut organisms 1, 2

Do not treat viral rhinosinusitis with antibiotics - antibiotics are only indicated when symptoms persist >10 days, are severe (high fever with purulent discharge for 3-4 days), or worsen after initial improvement 2, 5

Avoid macrolides as monotherapy - bacteriologic failure rates of 20-25% are common due to S. pneumoniae resistance, and azithromycin has poor activity against H. influenzae despite lack of formal resistance 1

Do not underdose amoxicillin-clavulanate - when treating DRSP risk, the high-dose regimen (4 g/250 mg in adults; 90 mg/6.4 mg per kg in children) is essential for adequate pharmacodynamic coverage 1

Watchful waiting is appropriate for otitis media - unless the child is <2 years with bilateral disease, a 2-3 day observation period with symptomatic treatment is reasonable before initiating antibiotics 1

Special Considerations

Chronic or recurrent sinusitis (≥3 episodes per year):

• Evaluate for underlying allergies, immunodeficiency, and anatomic abnormalities 2
• Consider referral to allergist-immunologist or otolaryngologist 2

Complicated sinusitis with meningeal signs, exophthalmos, or severe pain:

• Requires hospitalization, cultures, and parenteral antibiotics 2

Adjunctive therapies:

• Intranasal corticosteroids are beneficial, particularly in chronic hyperplastic eosinophilic rhinosinusitis 2
• Topical decongestants may help but limit use to <3-5 days to avoid rebound rhinitis medicamentosa 2, 4
• Antihistamines are NOT recommended for acute bacterial sinusitis but may help chronic sinusitis if allergic rhinitis is present 2