Treatment for Bacterial Sinusitis

First-Line Antibiotic Selection

The American Academy of Pediatrics and the Infectious Diseases Society of America recommend amoxicillin-clavulanate as the first-line antibiotic for acute bacterial sinusitis in both adults and children, with a treatment duration of 5-7 days in adults and 10-14 days in children 1, 2
Amoxicillin-clavulanate is strongly preferred over amoxicillin alone due to the increasing prevalence of β-lactamase-producing Haemophilus influenzae and Moraxella catarrhalis 1, 2, 3

For adults, the recommended dose of amoxicillin-clavulanate is 875 mg/125 mg twice daily (standard dose) or high-dose formulation (2 g amoxicillin/125 mg clavulanate twice daily) 1
For children, the standard dose is 45 mg/kg/day of amoxicillin component in 2 divided doses for mild-moderate disease in children ≥2 years without recent antibiotic exposure 3
For children <2 years, those in daycare, or with recent antibiotic use, the high dose is 80-90 mg/kg/day of amoxicillin component (maximum 2 g per dose) with 6.4 mg/kg/day clavulanate 3, 4

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 3, 4
Recommended alternatives include cefuroxime, cefpodoxime, cefdinir, or cefprozil 3, 6

Intranasal corticosteroids are recommended as adjunctive treatment, particularly in patients with allergic rhinitis, to reduce inflammation and improve outcomes 1, 2, 6
Intranasal saline irrigation (physiologic or hypertonic) is recommended in adults to improve mucociliary clearance and reduce nasal congestion 1, 2, 6

Reassess patients at 72 hours if symptoms worsen or fail to improve 1, 2, 4
Switch to alternative antibiotic if no improvement occurs after 3-5 days of initial therapy or if symptoms worsen within 48-72 hours 1, 2

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 3, 4
For severely ill or toxic-appearing patients, initiate inpatient IV therapy with cefotaxime or ceftriaxone and obtain otolaryngology consultation for possible sinus aspiration 4

Refer to otolaryngologist, infectious disease specialist, or allergist for immunocompromised patients, clinical deterioration despite extended antibiotic courses, recurrent sinusitis with clearing between episodes, or suspected complications (orbital or intracranial involvement) 1, 2, 3

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, 2
Do not use plain amoxicillin as first-line therapy given the high prevalence of β-lactamase-producing organisms 1, 2, 3
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
Do not continue ineffective antibiotics beyond 3-5 days—failure to reassess and switch therapy leads to prolonged illness and potential complications 1, 2, 6