What is the treatment for sinusitis?

Treatment of Sinusitis

For acute bacterial sinusitis in adults, start with amoxicillin-clavulanate 875/125 mg twice daily for 5-10 days as first-line therapy, reserving fluoroquinolones like levofloxacin for treatment failures or complicated disease. 1, 2

Confirming the Diagnosis Before Treatment

Before initiating antibiotics, confirm acute bacterial sinusitis using one of three clinical patterns 2:

• Persistent symptoms ≥10 days without improvement (nasal discharge, congestion, facial pain/pressure)
• Severe symptoms for ≥3 consecutive days (fever >39°C, purulent discharge, severe facial pain)
• "Double sickening" - worsening after initial improvement from a viral upper respiratory infection

Most acute rhinosinusitis is viral and resolves within 7 days without antibiotics 2. Imaging is not routinely required but may enhance diagnostic certainty in adults when the clinical picture is unclear 2.

First-Line Antibiotic Treatment

Standard Approach for Uncomplicated Disease

Amoxicillin-clavulanate 875/125 mg twice daily for 5-10 days is the preferred first-line agent 1, 2. This provides coverage against β-lactamase-producing H. influenzae and M. catarrhalis, which have become increasingly prevalent 2.

• Plain amoxicillin 500 mg twice daily remains acceptable for mild disease without recent antibiotic exposure 1
• For moderate disease, use amoxicillin 875 mg twice daily 1
• Treatment duration of 5-7 days has comparable efficacy to 10-14 days with fewer side effects 1
• Continue treatment until symptom-free for 7 days (typically 10-14 days total) 1, 2

High-Dose Regimens for Resistant Organisms

For regions with high bacterial resistance, recent antibiotic use, or more severe cases, use high-dose amoxicillin-clavulanate 1:

• Adults: 2000 mg amoxicillin with 125 mg clavulanate twice daily 1
• Pediatrics: 80-90 mg/kg/day of amoxicillin component with 6.4 mg/kg/day clavulanate in 2 divided doses 2

Important caveat: Recent research shows high-dose formulations may increase severe diarrhea (15.8% vs 4.8%) without consistently superior efficacy compared to standard dosing 3. The immediate-release high-dose formulation showed an 18% improvement rate at day 3, but the extended-release formulation showed no benefit 3.

Treatment for Penicillin-Allergic Patients

For documented penicillin allergy, the risk of cross-reactivity with second- and third-generation cephalosporins is negligible 1, 2:

• Second-generation cephalosporins: Cefuroxime axetil 1, 2
• Third-generation cephalosporins: Cefpodoxime proxetil or cefdinir (superior activity against H. influenzae) 1, 2

Critical pitfall: Azithromycin and other macrolides should NOT be used due to 20-25% resistance rates among S. pneumoniae and H. influenzae 1, 2. French and American guidelines explicitly exclude macrolides from recommended therapy 2.

For severe beta-lactam allergy where cephalosporins are contraindicated, doxycycline 100 mg once daily for 10 days is an option, though it has limited activity against H. influenzae and a 20-25% predicted bacteriologic failure rate 2.

Second-Line Treatment for Failure

If no improvement occurs after 3-5 days of initial therapy, switch to respiratory fluoroquinolones 1, 2:

• Levofloxacin 500-750 mg once daily for 5-10 days 1, 4
• Moxifloxacin is an alternative 1, 2

Fluoroquinolones provide 90-92% predicted clinical efficacy and excellent coverage against multi-drug resistant S. pneumoniae (MDRSP) 1, 2. The FDA label confirms levofloxacin's effectiveness for MDRSP with 95% clinical and bacteriologic success 4.

Reserve fluoroquinolones specifically for 1, 2:

• Treatment failures after 3-5 days
• Frontal, ethmoidal, or sphenoidal sinusitis (higher complication risk)
• Multi-drug resistant organisms
• Severe disease requiring hospitalization

Do not use fluoroquinolones as routine first-line therapy to prevent resistance development 1, 2.

Treatment Based on Anatomic Location

Maxillary Sinusitis (Most Common)

• Use standard first-line antibiotics (amoxicillin-clavulanate) 1, 2
• Symptoms: unilateral/bilateral infraorbital pain worsening when bending forward, pulsatile, peaking evening/night 2

Frontal, Ethmoidal, or Sphenoidal Sinusitis

• Consider fluoroquinolones (levofloxacin or moxifloxacin) due to higher risk of serious complications 1, 2
• These locations require more aggressive treatment 1

Adjunctive Therapies

Intranasal Corticosteroids

• Recommended as adjunct to antibiotics in both acute and chronic sinusitis 1, 2
• Particularly helpful with marked mucosal edema 1
• May decrease need for antibiotics 2

Oral Corticosteroids

• Consider short-term use (typically 5 days) for patients with 2:
  • Marked mucosal edema
  • Failure to respond to initial antibiotic treatment
  • Nasal polyposis
  • Acute hyperalgic sinusitis (severe pain)

Dexamethasone 4 mg may be used as short-term adjunctive therapy but should never be used as monotherapy for bacterial sinusitis 2.

Symptomatic Treatments

• Analgesics (acetaminophen, NSAIDs) for pain 2
• Saline nasal irrigation for symptomatic relief 2
• Decongestants (systemic or topical) as needed, though evidence is limited 1, 2
• Adequate hydration, warm facial packs, sleeping with head elevated 2

Pediatric Considerations

Standard Dosing

• Amoxicillin 45 mg/kg/day in 2 divided doses for mild disease 2
• High-dose amoxicillin 80-90 mg/kg/day in 2 divided doses for areas with high prevalence of resistant S. pneumoniae or risk factors (age <2 years, daycare attendance, recent antibiotic use) 2

Penicillin-Allergic Children

• Cefpodoxime proxetil 8 mg/kg/day in two doses 2
• Ceftriaxone 50 mg/kg as single dose for children unable to tolerate oral medication 2

Treatment Duration

• Same as adults: 10-14 days until symptom-free for 7 days 2
• Reassess at 72 hours if no improvement 2

Doxycycline is contraindicated in children <8 years old due to risk of tooth enamel discoloration 2.

Watchful Waiting Option

For adults with uncomplicated acute bacterial sinusitis, watchful waiting without immediate antibiotics is appropriate when follow-up can be assured 1:

• Start antibiotics if no improvement by 7 days or worsening at any time 1
• The number needed to treat with antibiotics is 3-5 for persistent symptoms 2
• This approach reduces unnecessary antibiotic exposure while maintaining safety 1

When to Escalate Care

Immediate Hospitalization Required

• Orbital involvement (periorbital cellulitis, vision changes) 1
• Neurological symptoms (severe headache, altered mental status, meningeal signs) 1
• These complications require parenteral antibiotics 1

Specialist Referral Indicated

• Symptoms persist after 21-28 days of antibiotic treatment 1
• Recurrent sinusitis (≥3 episodes per year) 2
• Need to clarify allergic or immunologic basis 2
• Sinusitis associated with unusual opportunistic infections 2

When referring for treatment failure, consider broader-spectrum antibiotics, anaerobic coverage, and CT imaging 1.

Critical Pitfalls to Avoid

• Do not use azithromycin - 20-25% resistance rates make it unsuitable for acute bacterial sinusitis 1, 2
• Complete the full antibiotic course even after symptoms improve to prevent relapse 2
• Reassess at 3-5 days if no improvement to avoid prolonged treatment failure 1, 2
• Reserve fluoroquinolones for second-line therapy only to prevent resistance 1, 2
• Ensure adequate treatment duration - minimum 5 days, typically 7-10 days, or until symptom-free for 7 days 1, 2
• Evaluate for underlying conditions in recurrent cases (allergies, immunodeficiency, anatomical abnormalities) 1, 2