Treatment of Sinusitis
The first-line treatment for acute bacterial sinusitis is amoxicillin-clavulanate, with respiratory fluoroquinolones reserved for patients with moderate disease or recent antibiotic use. 1
Diagnosis and Classification
Sinusitis can be classified as:
- Acute: Symptoms present for ~4 weeks
- Chronic: Symptoms present for ~3 months
- Subacute: Symptoms present for 1-3 months (less well-defined)
Medical Treatment
Antibiotic Therapy for Acute Bacterial Sinusitis
First-line options for mild disease (no recent antibiotic use):
- Amoxicillin-clavulanate (1.75-4 g/250 mg per day)
- Amoxicillin (1.5-4 g/day)
- Cefpodoxime proxetil
- Cefuroxime axetil
- Cefdinir 2
For patients with moderate disease or recent antibiotic use (within 4-6 weeks):
- Respiratory fluoroquinolones (gatifloxacin, levofloxacin, moxifloxacin)
- High-dose amoxicillin-clavulanate (4 g/250 mg per day) 2
For patients with β-lactam allergies:
- Trimethoprim/sulfamethoxazole
- Doxycycline
- Macrolides (azithromycin, clarithromycin)
- Telithromycin 2
- Pristinamycin 1
Note: β-lactam alternatives may have bacteriologic failure rates of 20-25% 2
Duration of therapy:
- Standard treatment duration is 7-10 days
- Short-course regimens with certain cephalosporins (cefuroxime-axetil, cefpodoxime-proxetil) have shown efficacy in 5-day regimens 1
- Levofloxacin is FDA-approved for acute bacterial sinusitis at either 750 mg daily for 5 days or 500 mg daily for 10-14 days 3
Treatment monitoring:
- If no clinical improvement within 72 hours (3 days), consider switching antibiotics or reevaluating the patient 2, 1
Treatment for Chronic Sinusitis
- Amoxicillin-clavulanate, clindamycin, or the combination of metronidazole and a penicillin 4
- Surgical procedures to facilitate sinus drainage may be necessary 2
- Combined medical and surgical treatment has >60% cure rate after 3 years of follow-up 2
Adjunctive Therapies
- Intranasal corticosteroids: Recommended as adjunctive therapy, especially for allergic or inflammatory components 1
- Nasal saline irrigations: Improve mucociliary clearance and prevent crust formation 1
- Decongestants: Help reduce mucosal edema and improve drainage 5
- Steam inhalation: Promotes drainage and secretion clearance 6, 5
Caution: NSAIDs at anti-inflammatory doses have not demonstrated efficacy in sinusitis 1 Caution: Antihistamines are indicated only when a patient has concomitant allergies and is symptomatic during allergy season 5
Surgical Treatment
Indications for Functional Endoscopic Sinus Surgery (FESS):
- Chronic rhinosinusitis refractory to medical treatment (symptoms >12 weeks)
- Complications of acute sinusitis (orbital or intracranial involvement)
- Anatomic abnormalities contributing to sinus obstruction
- Specific pathological conditions (nasal polyps, fungal disease, osteitis) 1
Surgical Approach:
- Conservative approach recommended for primary surgery
- Procedures tailored to disease extent identified on CT and intraoperative findings
- Limited surgery rather than routine complete ethmoidectomy 1
Common Pitfalls and Caveats
Antibiotic resistance: The prevalence of β-lactamase-producing strains among respiratory pathogens is increasing (up to 20% of H. influenzae, 50-70% of M. catarrhalis) 7
Inadequate duration: Some recommend continuing treatment until the patient is symptom-free and then for an additional 7 days 7
Overlooking underlying conditions: Sinusitis can be linked to allergic rhinitis, asthma, and nasal polyps 8
Failure to recognize complications: Complications of acute and chronic sinusitis include intraorbital and intracranial sepsis, which require urgent evaluation with CT scanning, IV antibiotics, and possibly surgical drainage 6
Inappropriate antihistamine use: Antihistamines may thicken secretions and should only be used when allergies are clearly contributing to symptoms 5
By following these evidence-based guidelines for the treatment of sinusitis, clinicians can optimize outcomes while minimizing antibiotic resistance and complications.