Treatment for Bacterial Sinusitis
Amoxicillin-clavulanate is the recommended 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 increasing prevalence of β-lactamase-producing Haemophilus influenzae and Moraxella catarrhalis, which now account for a significant proportion of sinusitis cases. 1
Dosing Recommendations
Adults: Amoxicillin-clavulanate 875 mg/125 mg twice daily (standard dose) or high-dose formulation (2 g amoxicillin/125 mg clavulanate twice daily) 1
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 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 1
High-dose amoxicillin-clavulanate should be used in communities with >10% penicillin-resistant Streptococcus pneumoniae, in children with risk factors (age <2 years, daycare attendance, recent antibiotic use within 30 days), or in patients with moderate-to-severe illness. 1
Treatment Duration
- Adults: 5-7 days is sufficient for uncomplicated cases 1
- Children: 10-14 days remains the standard recommendation 1
- Alternative approach: Continue antibiotics for 7 days after symptom resolution, with minimum total duration of 10 days 1
Penicillin-Allergic Patients
For non-severe penicillin allergy, second- or third-generation cephalosporins are safe and effective alternatives, as the risk of cross-reactivity causing serious allergic reactions is negligible. 1
- Recommended alternatives: Cefuroxime, cefpodoxime, cefdinir, or cefprozil 1, 2
- For adults with true type 1 hypersensitivity: Respiratory fluoroquinolones (levofloxacin 500-750 mg daily or moxifloxacin) 3, 4
Avoid azithromycin and other macrolides as empiric therapy due to high resistance rates among S. pneumoniae and H. influenzae, with predicted clinical efficacy of only 77-81% compared to 87-91% for first-line agents. 3
Doxycycline has limited effectiveness with bacterial failure rates of 20-25% and should only be considered when other options are contraindicated, with close monitoring for treatment failure. 3
Adjunctive Therapies
Intranasal corticosteroids are recommended as adjunctive treatment, particularly in patients with allergic rhinitis, to reduce inflammation and improve outcomes. 1, 2
Intranasal saline irrigation (physiologic or hypertonic) is recommended in adults to improve mucociliary clearance and reduce nasal congestion. 1, 2
Avoid topical or oral decongestants and antihistamines as routine adjunctive therapy, as they provide no proven benefit and decongestants can cause rebound congestion with prolonged use. 1, 2
Monitoring and Treatment Failure
Reassess patients at 72 hours if symptoms worsen or fail to improve. 1
Switch to alternative antibiotic if no improvement occurs after 3-5 days of initial therapy or if symptoms worsen within 48-72 hours. 1
Second-Line Options for Treatment Failure
When changing antibiotics, consider broader coverage:
- High-dose amoxicillin-clavulanate if standard dose was used initially 1
- Respiratory fluoroquinolones (levofloxacin, moxifloxacin) for adults 3, 4
- Consider sinus aspiration for culture if patient fails multiple antibiotic courses 1
Special Clinical Situations
For patients unable to tolerate oral medications (vomiting, severe illness), administer ceftriaxone 50 mg/kg IV or IM as a single dose, then transition to oral therapy once tolerated. 1
For severely ill or toxic-appearing patients, initiate inpatient IV therapy with cefotaxime or ceftriaxone and obtain otolaryngology consultation for possible sinus aspiration. 1
When to Refer to Specialist
Refer to otolaryngologist, infectious disease specialist, or allergist for:
- Immunocompromised patients 1
- Clinical deterioration despite extended antibiotic courses 1
- Recurrent sinusitis with clearing between episodes 1
- Suspected complications (orbital or intracranial involvement) 1
Critical Pitfalls to Avoid
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
Do not use plain amoxicillin as first-line therapy given the high prevalence of β-lactamase-producing organisms. 1
Do not prescribe antibiotics for viral rhinosinusitis—ensure patients meet diagnostic criteria (symptoms >10 days without improvement, severe symptoms with high fever and purulent discharge for 3-4 days, or worsening after initial improvement). 1, 5
Do not continue ineffective antibiotics beyond 3-5 days—failure to reassess and switch therapy leads to prolonged illness and potential complications. 1, 2