Treatment of Maxillary Sinusitis
Confirm the Diagnosis Before Prescribing Antibiotics
Most cases of acute rhinosinusitis (98-99.5%) are viral and resolve spontaneously within 7-10 days without antibiotics. 1
Prescribe antibiotics only when the patient meets at least one of these three criteria for bacterial maxillary sinusitis:
- Persistent symptoms ≥10 days without improvement (purulent nasal discharge plus facial pain/pressure or nasal obstruction) 1, 2
- Severe symptoms ≥3-4 consecutive days with fever ≥39°C, purulent nasal discharge, and unilateral facial pain 1, 2
- "Double sickening" – initial improvement from a cold followed by worsening within 10 days 1, 2
Do not prescribe antibiotics for symptoms lasting <10 days unless severe features are present. 1, 2
First-Line Antibiotic Treatment
Amoxicillin-clavulanate 875 mg/125 mg twice daily for 5-10 days is the preferred first-line antibiotic for acute bacterial maxillary sinusitis in adults. 3, 1, 2
This regimen provides 90-92% predicted clinical efficacy against the three major pathogens: Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. 1 The clavulanate component is essential because 30-40% of H. influenzae and 90-100% of M. catarrhalis produce β-lactamase, rendering plain amoxicillin ineffective. 3, 1
Treatment duration: Continue for 5-10 days or until symptom-free for 7 consecutive days (typically 10-14 days total). 3, 1, 2 Recent evidence supports shorter 5-7 day courses with comparable efficacy and fewer adverse effects. 1, 2
Plain amoxicillin 500 mg twice daily (mild disease) or 875 mg twice daily (moderate disease) remains acceptable for uncomplicated cases without recent antibiotic exposure, though amoxicillin-clavulanate is increasingly preferred. 1, 2
High-Dose Regimen for Specific Risk Factors
Use high-dose amoxicillin-clavulanate (2 g/125 mg twice daily) for patients with:
- Recent antibiotic use within the past 4-6 weeks 1, 2
- Age >65 years 1, 2
- Moderate-to-severe symptoms 1, 2
- Comorbid conditions or immunocompromised state 1, 2
- Daycare attendance (pediatric patients) 1
Alternatives for Penicillin-Allergic Patients
Non-Severe (Non-Type I) Penicillin Allergy
Second- or third-generation cephalosporins are the preferred alternatives because cross-reactivity with penicillin is negligible. 3, 1, 2
Options include:
- Cefuroxime-axetil (second-generation) 3, 2
- Cefpodoxime-proxetil (third-generation) 3, 1, 2
- Cefdinir (third-generation) 1, 2
- Cefprozil (second-generation) 1
Standard duration is 10 days, though some cephalosporins (cefuroxime-axetil, cefpodoxime-proxetil) are effective in 5-day courses. 3, 2
Severe (Type I/Anaphylactic) Penicillin Allergy
Respiratory fluoroquinolones are the treatment of choice for patients with documented severe β-lactam allergy. 1, 2
- Levofloxacin 500 mg once daily for 10-14 days 3, 1, 2
- Moxifloxacin 400 mg once daily for 10 days 3, 1, 2
These agents provide 90-92% predicted efficacy against multidrug-resistant S. pneumoniae and complete coverage of β-lactamase-producing organisms. 1
Pristinamycin is an alternative for patients with β-lactam allergies in regions where it is available. 3, 4
Antibiotics to Avoid
Never use azithromycin or other macrolides as first-line therapy due to resistance rates of 20-25% for both S. pneumoniae and H. influenzae. 1, 2
Avoid trimethoprim-sulfamethoxazole due to 50% resistance in S. pneumoniae and 27% resistance in H. influenzae. 1
Do not use first-generation cephalosporins (cephalexin, cefadroxil) because they provide inadequate coverage against H. influenzae (≈50% of strains produce β-lactamase). 1
Doxycycline has a predicted bacteriologic failure rate of 20-25% and should be reserved only for penicillin-allergic patients who cannot use cephalosporins or fluoroquinolones. 1
Essential Adjunctive Therapies (Add to All Patients)
Intranasal corticosteroids (mometasone, fluticasone, or budesonide) twice daily significantly reduce mucosal inflammation and accelerate symptom resolution. 3, 1, 2 This recommendation is supported by strong evidence from multiple randomized controlled trials. 1
Saline nasal irrigation 2-3 times daily provides symptomatic relief and helps clear mucus. 1, 2
Analgesics (acetaminophen or ibuprofen) for pain and fever control. 1, 2
Short-term oral corticosteroids may be considered for patients with marked mucosal edema or acute hyperalgic sinusitis (severe pain), typically for 5 days. 3, 4 However, NSAIDs at anti-inflammatory doses have not demonstrated proven efficacy in sinusitis. 3, 4
Decongestants (oral or topical) may provide symptomatic relief, but limit topical agents to ≤3 days to avoid rebound congestion (rhinitis medicamentosa). 2
Watchful Waiting Strategy
Initial observation without immediate antibiotics is appropriate for uncomplicated maxillary sinusitis when reliable follow-up can be ensured. 1, 2
Start antibiotics only if:
The number needed to treat with antibiotics is 10-15 to achieve one additional cure over 7-15 days, reflecting the high rate of spontaneous recovery. 1
Monitoring and Reassessment
Reassess at 3-5 days: If no clinical improvement, switch to high-dose amoxicillin-clavulanate (if not already prescribed) or a respiratory fluoroquinolone. 3, 1, 2 If symptoms worsen, evaluate urgently for complications (orbital cellulitis, meningitis, brain abscess). 1
Reassess at 7 days: If symptoms persist or worsen, reconfirm the diagnosis, exclude complications, and consider switching to second-line therapy. 1, 2 Reserve CT imaging only for suspected complications or alternative diagnoses—do not obtain routine imaging for uncomplicated maxillary sinusitis. 1
Waiting beyond 7 days to change therapy in non-responders delays effective treatment and may allow complications to develop. 1
Second-Line Treatment for Treatment Failure
If the patient fails initial therapy after 3-5 days:
- Switch to high-dose amoxicillin-clavulanate (2 g/125 mg twice daily) if not already prescribed 1, 2
- Or switch to a respiratory fluoroquinolone (levofloxacin 500 mg once daily for 10-14 days or moxifloxacin 400 mg once daily for 10 days) 3, 1, 2
- Third-generation cephalosporins (cefpodoxime-proxetil, cefdinir) offer superior activity against H. influenzae compared to second-generation agents 1
Ceftriaxone 1-2 g IM or IV once daily for 5 days is indicated when the patient cannot tolerate oral medications, has moderate-to-severe disease with recent antibiotic exposure, or has failed oral therapy. 1
When to Refer to Otolaryngology
Refer patients when:
- No improvement after 7 days of appropriate second-line antibiotic therapy 1, 2
- Worsening symptoms at any point during treatment 1, 2
- Suspected complications (orbital cellulitis, meningitis, intracranial abscess, severe headache, visual changes, periorbital swelling, altered mental status) 1, 2
- Recurrent sinusitis (≥3 episodes per year) requiring evaluation for underlying allergic rhinitis, immunodeficiency, or anatomic abnormalities 3, 1
Pediatric Dosing Considerations
Standard-dose amoxicillin: 45 mg/kg/day divided into 2 doses 1
High-dose amoxicillin: 80-90 mg/kg/day divided into 2 doses for children with risk factors (age <2 years, daycare attendance, recent antibiotic use, or high local resistance) 3, 1
High-dose amoxicillin-clavulanate: 80-90 mg/kg/day of amoxicillin component with 6.4 mg/kg/day clavulanate divided into 2 doses 3, 1
Treatment duration for children: Minimum 10-14 days (longer than adult courses) 3, 1
Reassess pediatric patients at 72 hours: If no improvement or worsening, switch to high-dose amoxicillin-clavulanate. 3, 1
Ceftriaxone 50 mg/kg IM as a single dose for children who are vomiting, cannot take oral medications, or are unlikely to comply with initial doses. 1
Critical Pitfalls to Avoid
Do not prescribe antibiotics based solely on purulent nasal discharge or mucus color—these reflect neutrophils, not bacteria, and are present in viral infections. 1
Do not obtain routine CT or X-ray for uncomplicated maxillary sinusitis—87% of viral upper respiratory infections show sinus abnormalities on imaging, leading to unnecessary interventions. 1
Ensure adequate treatment duration (≥5 days for adults, ≥10 days for children) to prevent relapse. 3, 1, 2
Do not use fluoroquinolones as routine first-line therapy in patients without documented β-lactam allergies—reserve them to prevent resistance development. 3, 1, 2
Gastrointestinal adverse effects are more common with amoxicillin-clavulanate (diarrhea in 40-43% of patients, severe diarrhea in 7-8%), so counsel patients accordingly. 1
Perform early reassessment at 3-5 days—delaying changes in non-responders can allow complications to develop. 1
Special Considerations
Odontogenic Maxillary Sinusitis
Consider an odontogenic source in patients with a history of dental or jaw pain, dental infection, or oral/periodontal/endodontic surgery. 5 Odontogenic infections are polymicrobial aerobic-anaerobic infections requiring appropriate antibiotics, surgical drainage when indicated, and treatment to remove the offending dental etiology. 5
Chronic or Recurrent Sinusitis
Patients with symptoms lasting >8 weeks (chronic sinusitis) or ≥3 episodes per year (recurrent sinusitis) require evaluation for underlying allergic rhinitis, immunodeficiency, or anatomic abnormalities. 3, 1 Chronic hyperplastic eosinophilic rhinosinusitis does not respond to antibiotics and requires systemic corticosteroids. 1