What antibiotic covers bacterial sinusitis?

Antibiotic Treatment for Bacterial Sinusitis

Amoxicillin-clavulanate 875 mg/125 mg twice daily for 5-10 days is the preferred first-line antibiotic for acute bacterial sinusitis in adults, providing the best balance of efficacy against resistant pathogens and tolerability. 1

First-Line Treatment Algorithm

For Adults Without Recent Antibiotic Use (Past 4-6 Weeks)

Primary recommendation:

• Amoxicillin-clavulanate 875 mg/125 mg twice daily achieves 90-91% clinical efficacy and 97-99% bacteriologic efficacy 2
• Treatment duration: 5-10 days (shorter courses have comparable efficacy with fewer side effects) 1

Alternative options if amoxicillin-clavulanate unavailable:

• Plain amoxicillin 500 mg twice daily (mild disease) or 875 mg twice daily (moderate disease) achieves 87-88% clinical efficacy 2
• Cefpodoxime proxetil (87% efficacy), cefuroxime axetil (85% efficacy), or cefdinir (83% efficacy) 2

For Adults With Recent Antibiotic Use or Moderate Disease

Escalate to broader coverage:

• Respiratory fluoroquinolones (levofloxacin 500-750 mg daily, moxifloxacin) achieve 92% clinical efficacy and 100% bacteriologic efficacy 2, 3
• High-dose amoxicillin-clavulanate 4 g/250 mg daily (91% efficacy) 2
• Ceftriaxone 1-2 g IV daily (91% efficacy) 2

For Penicillin-Allergic Patients

Non-Type I hypersensitivity (e.g., rash):

• Second-generation cephalosporins: cefuroxime-axetil 2, 1
• Third-generation cephalosporins: cefpodoxime-proxetil or cefdinir 2, 1
• Risk of cross-reactivity with second/third-generation cephalosporins is negligible 1

True Type I hypersensitivity (anaphylaxis):

• TMP/SMX (83% efficacy) or doxycycline (81% efficacy) 2
• Avoid azithromycin and macrolides due to 20-25% resistance rates and only 77% efficacy 2, 1

Pediatric Dosing

Standard-dose for uncomplicated cases:

• Amoxicillin 45 mg/kg/day divided twice daily for children without recent antibiotic use, not in daycare, and aged >2 years 1, 4, 5

High-dose for risk factors:

• Amoxicillin-clavulanate 90 mg/kg/day (amoxicillin component) with 6.4 mg/kg/day clavulanate divided twice daily for children <2 years, daycare attendance, recent antibiotic use, or high local resistance 1, 4, 5
• Treatment duration: 10-14 days 1, 4

Treatment Failure Protocol

Reassess at 72 hours (pediatrics) or 3-5 days (adults):

• If no improvement or worsening, switch antibiotics considering limitations of initial agent 2, 1
• For amoxicillin failure: switch to amoxicillin-clavulanate 2, 4
• For amoxicillin-clavulanate failure: switch to respiratory fluoroquinolones (levofloxacin, moxifloxacin) 2, 1
• For pediatric treatment failure at 72 hours: high-dose amoxicillin-clavulanate or ceftriaxone 50 mg/kg IM/IV 4

Anatomic Location Considerations

Maxillary sinusitis (most common):

• Standard first-line antibiotics (amoxicillin-clavulanate) are appropriate 1

Frontal, ethmoidal, or sphenoidal sinusitis:

• Reserve fluoroquinolones (levofloxacin, moxifloxacin) due to potential for serious complications 1

Adjunctive Therapies

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

Critical Pitfalls to Avoid

Resistance patterns:

• 10-15% of S. pneumoniae are penicillin-resistant, 10-42% of H. influenzae produce β-lactamase, and nearly 100% of M. catarrhalis produce β-lactamase 5
• High-dose amoxicillin (4 g/day) or amoxicillin-clavulanate (4 g/250 mg) needed for drug-resistant S. pneumoniae (DRSP) 2

Inappropriate antibiotic selection:

• Never use azithromycin or macrolides as first-line therapy due to 20-25% resistance and inferior efficacy (77% vs 90-91% for amoxicillin-clavulanate) 2, 1
• Reserve fluoroquinolones as second-line to prevent resistance development 1

Inadequate treatment duration:

• Minimum 5 days, typically 7-10 days, or until symptom-free for 7 days 1, 5
• Complete full course even after symptom improvement to prevent relapse 1

Watchful waiting option:

• For uncomplicated acute bacterial sinusitis in adults 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