From the Guidelines
The best antibiotic for sinusitis is amoxicillin-clavulanate (Augmentin), typically prescribed as 875/125 mg twice daily for 5-7 days for uncomplicated cases. For patients with penicillin allergy, alternatives include doxycycline (100 mg twice daily) or a respiratory fluoroquinolone like levofloxacin (750 mg daily) 1. Antibiotic treatment should generally be reserved for bacterial sinusitis, characterized by symptoms lasting more than 10 days, severe symptoms with high fever (>102°F) and purulent discharge, or worsening symptoms after initial improvement. Before starting antibiotics, supportive measures like saline irrigation, intranasal corticosteroids (such as fluticasone 1-2 sprays per nostril daily), and analgesics can help manage symptoms. Amoxicillin-clavulanate is preferred over amoxicillin alone because it covers beta-lactamase-producing organisms like Haemophilus influenzae and Moraxella catarrhalis, which are common sinusitis pathogens alongside Streptococcus pneumoniae 1. Most cases of sinusitis are viral and will resolve without antibiotics, so judicious use of antimicrobials is important to prevent resistance development.
Some key points to consider:
- The American Academy of Otolaryngology–Head and Neck Surgery emphasizes watchful waiting (without antibiotic therapy) as initial management for all patients with uncomplicated ABRS, regardless of severity 1.
- A meta-analysis of adults with acute rhinosinusitis showed that the number needed to treat was 18 for 1 patient to be cured rapidly, but the number needed to harm from adverse effects from antibiotics was 8 1.
- Patients who are seriously ill, who deteriorate clinically despite antibiotic therapy, or who have recurrent episodes should be referred to a specialist (for example, an otolaryngologist, infectious disease specialist, or allergist) 1.
It's also important to note that the diagnosis of bacterial sinusitis is often based on clinical criteria, as radiographic imaging has no role in ascertaining a bacterial cause and may increase costs without adding benefit 1. The 2012 IDSA clinical practice guidelines recommend empirical antibiotics as soon as a clinical diagnosis of ABRS is established on the basis of clinical criteria, with amoxicillin–clavulanate as the preferred agent 1.
From the FDA Drug Label
Levofloxacin tablets are indicated for the treatment of acute bacterial sinusitis due to Streptococcus pneumoniae, Haemophilus influenzae, or Moraxella catarrhalis [see Clinical Studies (14.4)]. To evaluate the safety and efficacy of a high dose short course of levofloxacin, 780 outpatient adults with clinically and radiologically determined acute bacterial sinusitis were evaluated in a double-blind, randomized, prospective, multicenter study comparing levofloxacin 750 mg by mouth once daily for five days to levofloxacin 500 mg by mouth once daily for 10 days Clinical success rates (defined as complete or partial resolution of the pre-treatment signs and symptoms of ABS to such an extent that no further antibiotic treatment was deemed necessary) in the microbiologically evaluable population were 91.4% (139/152) in the levofloxacin 750 mg group and 88.6% (132/149) in the levofloxacin 500 mg group at the test-of-cure (TOC) visit (95% CI [-4. 2,10] for levofloxacin 750 mg minus levofloxacin 500 mg).
Best sinusitis ABX:
- Levofloxacin 750 mg by mouth once daily for 5 days with a clinical success rate of 91.4%
- Levofloxacin 500 mg by mouth once daily for 10 days with a clinical success rate of 88.6% 2
From the Research
Treatment Options for Sinusitis
- Amoxicillin with clavulanate is a commonly recommended treatment for acute bacterial sinusitis in adults, providing modest benefit 3.
- High-dose amoxicillin may lead to more rapid improvement in symptoms, but also increases the risk of severe diarrhea 3.
- Narrow-spectrum antibiotics such as amoxicillin should be used for 10 to 14 days to avoid the emergence and spread of antibiotic-resistant bacteria 4.
- Second-line antibiotics such as amoxicillin-clavulanate potassium and fluoroquinolones may be considered for patients with moderate disease or recent antibiotic use 4.
Duration of Antibiotic Therapy
- The traditional 10- to 14-day duration of therapy is not derived from a strong scientific or medical rationale, and short-course antibiotic therapy may have equivalent or superior efficacy 5.
- A 5-day course of antibiotic therapy may be sufficient for uncomplicated acute maxillary sinusitis in adults, with advantages including reduced risk of antibiotic resistance and side effects 5.
- Short-course therapy with azithromycin (3-day course) has been shown to be as effective and well-tolerated as a 10-day course of amoxicillin/clavulanic acid in the treatment of acute sinusitis 6.