What is the recommended antibiotic for bacterial sinus infection in adults?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: September 1, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

Recommended Antibiotic Treatment for Bacterial Sinus Infection in Adults

Amoxicillin-clavulanate is the recommended first-line antibiotic treatment for acute bacterial rhinosinusitis in adults, with a dosage of 875/125 mg twice daily for 5-7 days. 1

Diagnosis of Acute Bacterial Rhinosinusitis (ABRS)

Before initiating antibiotic therapy, it's important to distinguish bacterial from viral sinusitis. ABRS is more likely when:

  • Symptoms persist for more than 10 days without clinical improvement
  • Symptoms are severe (fever >39°C, purulent nasal discharge, or facial pain lasting for >3 consecutive days)
  • Symptoms worsen after an initial period of improvement ("double sickening") for more than 3 days 2

First-Line Antibiotic Therapy

  • Amoxicillin-clavulanate (875/125 mg twice daily for 5-7 days) 1, 2
    • Provides coverage against common pathogens including ampicillin-resistant Haemophilus influenzae and Moraxella catarrhalis
    • The addition of clavulanate addresses beta-lactamase producing organisms

Alternative Antibiotic Options for Penicillin-Allergic Patients

For patients with penicillin allergy:

  • Non-Type I hypersensitivity: Cefuroxime (500 mg twice daily) or cefpodoxime (200-400 mg twice daily) 1, 3
  • Type I hypersensitivity: Doxycycline (100 mg twice daily) or trimethoprim-sulfamethoxazole 1
  • Respiratory fluoroquinolones (levofloxacin 500 mg once daily or moxifloxacin 400 mg once daily) should be reserved for treatment failures or severe allergies due to potential adverse effects 1, 4, 5

Duration of Treatment

  • 5-7 days of treatment is sufficient for uncomplicated cases in adults 1, 2
  • Longer courses may be needed for patients with underlying conditions or severe infections

Management of Treatment Failure

If a patient fails to improve with the initial management option by 7 days after diagnosis or worsens during the initial management:

  1. Reassess the patient to confirm ABRS
  2. Exclude other causes of illness
  3. Detect complications 2

If ABRS is confirmed in a patient initially managed with observation, begin antibiotic therapy. If the patient was initially managed with an antibiotic, change the antibiotic 2.

Adjunctive Treatments

  • Intranasal saline irrigation is recommended to improve mucociliary clearance 1
  • Intranasal corticosteroids are beneficial as an adjunct to antibiotics, especially in patients with a history of allergic rhinitis 1
  • Analgesics (acetaminophen or NSAIDs) may be used for pain relief 1

Risk Factors for Resistant Pathogens

Consider high-dose amoxicillin-clavulanate (2000 mg amoxicillin component twice daily) for patients with:

  • Recent antibiotic use (within 4-6 weeks)
  • Healthcare exposure
  • Immunocompromised status 1

Important Cautions

  • Azithromycin is not recommended as first-line therapy due to high rates of resistance among S. pneumoniae and limited effectiveness against the major pathogens of ABRS 1
  • Fluoroquinolones carry FDA black box warnings for tendinitis, tendon rupture, and peripheral neuropathy 1
  • The American Academy of Otolaryngology–Head and Neck Surgery emphasizes watchful waiting (without antibiotic therapy) as initial management for uncomplicated ABRS, with antibiotics reserved for patients who fail to improve 2

When to Refer to a Specialist

Referral to an otolaryngologist is necessary if:

  • Complications are suspected
  • Symptoms persist despite adequate therapy
  • Recurrent episodes occur 1

By following these evidence-based recommendations, clinicians can effectively manage acute bacterial rhinosinusitis while promoting appropriate antibiotic stewardship.

References

Guideline

Acute Bacterial Sinusitis Treatment Guidelines

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Beginning antibiotics for acute rhinosinusitis and choosing the right treatment.

Clinical reviews in allergy & immunology, 2006

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.