What is the recommended treatment for bacterial sinusitis?

Treatment for Bacterial Sinusitis

Amoxicillin-clavulanate is the first-line antibiotic for acute bacterial sinusitis in both adults and children, with treatment duration of 5-7 days in adults and 10-14 days in children. 1

First-Line Antibiotic Selection

Amoxicillin-clavulanate is strongly preferred over amoxicillin alone due to the high prevalence of β-lactamase-producing Haemophilus influenzae (approximately 50%) and Moraxella catarrhalis (90-100%) in most geographic areas. 2, 1 This recommendation is supported by both the American Academy of Pediatrics and the Infectious Diseases Society of America. 1

Dosing Recommendations

For adults:

• Standard dose: 500-875 mg/125 mg twice daily 2, 1
• High-dose formulation: 2 g amoxicillin/125 mg clavulanate twice daily (maximum dose not to exceed 2 g every 12 hours) 2, 1

For children:

• Standard dose: 45 mg/kg/day of amoxicillin component in 2 divided doses for mild-moderate disease in children ≥2 years without recent antibiotic exposure 2, 1
• High dose: 80-90 mg/kg/day of amoxicillin component (maximum 2 g per dose) with 6.4 mg/kg/day clavulanate for children <2 years, those in daycare, or with recent antibiotic use 2, 1

The high-dose regimen overcomes penicillin resistance in Streptococcus pneumoniae (25-50% of strains are relatively or highly resistant) in most cases. 2

Treatment Duration

Adults should receive 5-7 days of treatment for uncomplicated cases, which is sufficient based on meta-analysis data showing equivalent efficacy to 10-14 day courses. 1, 3, 4 The traditional 10-14 day course is not derived from strong scientific rationale and shorter courses reduce adverse events, improve compliance, and decrease resistance development. 3, 4

Children should receive 10-14 days of treatment, as this remains the standard pediatric recommendation. 2, 1 Some experts suggest continuing treatment until the patient is symptom-free plus an additional 7 days. 2

Alternative Antibiotics for Penicillin-Allergic Patients

For non-severe penicillin allergy, second- or third-generation cephalosporins are safe alternatives, as the risk of cross-reactivity causing serious allergic reactions is negligible. 2, 1

Recommended cephalosporin alternatives include:

• Cefuroxime: 250-500 mg twice daily (adults), 7.5 mg/kg twice daily (children) 2, 1
• Cefpodoxime: 200-400 mg twice daily (adults), 5 mg/kg twice daily (children) 2, 1
• Cefdinir: appropriate alternative with good coverage 2, 1
• Cefprozil: 250-500 mg twice daily (adults), 15 mg/kg twice daily (children) 2, 1

Avoid cefixime and ceftibuten as they have poor activity against S. pneumoniae, especially penicillin-resistant strains. 2

For serious penicillin allergy:

• Macrolides (clarithromycin or azithromycin) may be prescribed, though they have relatively weak activity against some pathogens 2, 5
• Respiratory fluoroquinolones (levofloxacin, moxifloxacin, gatifloxacin) are effective alternatives in adults 2, 6

Fluoroquinolone Options (Adults Only)

Levofloxacin is FDA-approved for acute bacterial sinusitis with two regimens: 750 mg once daily for 5 days or 500 mg once daily for 10-14 days. 7 Clinical success rates are equivalent between the 5-day (91.4%) and 10-day (88.6%) regimens. 7

Other fluoroquinolones with specific indications for sinusitis include moxifloxacin, gatifloxacin, and gemifloxacin. 2 These agents provide excellent coverage against resistant S. pneumoniae and β-lactamase-producing organisms. 6, 8

Reassessment and Treatment Failure

Reassess patients at 72 hours if symptoms worsen or fail to improve. 2, 1 In randomized trials, 51% of placebo-treated patients improved within 3 days, with minimal additional improvement between days 3-10. 2

If no improvement occurs after 3-5 days of initial therapy, switch to an alternative antibiotic. 2, 1 For poor response to amoxicillin or in regions with high antibiotic resistance, appropriate choices include:

• High-dose amoxicillin-clavulanate 2
• Cefuroxime, cefpodoxime, or cefdinir 2
• Respiratory fluoroquinolones 2

For sinusitis failing to improve after 21-28 days, consider broader-spectrum coverage with or without anaerobic coverage (clindamycin or metronidazole), as anaerobic pathogens may be involved in protracted cases. 2

Adjunctive Therapies

Intranasal corticosteroids are recommended as adjunctive treatment, particularly in patients with allergic rhinitis, to reduce inflammation and improve outcomes. 2, 1

Intranasal saline irrigation (physiologic or hypertonic) is recommended in adults to improve mucociliary clearance and reduce nasal congestion. 1

Comfort measures include adequate rest, hydration, analgesics, warm facial packs, steamy showers, and sleeping with the head of bed elevated. 2

Special Clinical Situations

For severely ill or toxic-appearing patients:

• Initiate inpatient IV therapy with cefotaxime or ceftriaxone 2, 1
• Obtain otolaryngology consultation for possible sinus aspiration 2, 1

For patients unable to tolerate oral medications:

• Administer ceftriaxone 50 mg/kg IV or IM as a single dose, then transition to oral therapy once tolerated 1

When to Refer to a Specialist

Consultation with an allergist-immunologist, otolaryngologist, or infectious disease specialist is indicated for:

• Recurrent sinusitis (≥3 episodes per year) 2
• Chronic sinusitis refractory to usual antibiotic treatment 2
• Suspected orbital or intracranial complications 2, 1
• Immunocompromised patients 1
• Unusual opportunistic infections 2
• Need to clarify allergic or immunologic basis 2

Critical Pitfalls to Avoid

Do not use plain amoxicillin as first-line therapy given the high prevalence (50-100%) of β-lactamase-producing H. influenzae and M. catarrhalis. 2, 1

Do not prescribe antibiotics for viral rhinosinusitis. Ensure patients meet diagnostic criteria: symptoms >10 days without improvement, severe symptoms with high fever (≥39°C) and purulent discharge for 3-4 consecutive days, or worsening after initial improvement. 2, 1 Bacterial sinusitis is uncommon in patients with symptoms lasting less than 10 days. 2

Do not continue ineffective antibiotics beyond 3-5 days without reassessment—failure to switch therapy leads to prolonged illness and potential complications. 2, 1

Do not routinely cover for MRSA during initial empiric therapy, as current data do not support this practice despite S. aureus being a potential pathogen. 1

Avoid first-generation cephalosporins (cephalexin, cefadroxil) as they have poor coverage for H. influenzae. 2

Avoid cefaclor due to inadequate activity against β-lactamase-producing organisms and high prevalence of serum sickness-like reactions. 2