What are the antibiotic (abx) choices for acute sinus infection?

From the Guidelines

For acute bacterial sinusitis, first-line antibiotic treatment is amoxicillin with or without clavulanate for 5 to 10 days for most adults. This recommendation is based on the most recent and highest quality study available, which suggests that amoxicillin with or without clavulanate is the preferred agent for treating acute bacterial rhinosinusitis (ABRS) 1.

Key Considerations

• 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.
• Alternatives for penicillin-allergic patients include doxycycline or a respiratory fluoroquinolone, but the choice of antibiotic should be guided by local resistance patterns and patient-specific factors 1.
• Most cases of sinusitis are viral and should be managed symptomatically for 7-10 days before considering antibiotics, and only prescribe antibiotics when bacterial infection is likely, indicated by symptoms lasting over 10 days, severe symptoms with fever, or worsening symptoms after initial improvement 1.
• Supportive measures like saline irrigation, intranasal corticosteroids, and analgesics should be used regardless of whether antibiotics are prescribed, as they can help alleviate symptoms and improve quality of life 1.

Targeted Pathogens

The recommended antibiotics target the most common bacterial pathogens in acute sinusitis, including:

• Streptococcus pneumoniae
• Haemophilus influenzae
• Moraxella catarrhalis

High-Risk Patients

For patients with risk factors for resistant organisms, such as recent antibiotic use, healthcare exposure, or in areas with high pneumococcal resistance, consider alternative or high-dose antibiotic regimens, but always prioritize the most recent and highest quality evidence available 1.

From the FDA Drug Label

1. 4 Acute Bacterial Sinusitis: 5 Day and 10 to 14 Day Treatment Regimens Levofloxacin is approved for the treatment of acute bacterial sinusitis (ABS) using either 750 mg by mouth x 5 days or 500 mg by mouth once daily x 10 to 14 days 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).

Acute Bacterial Sinusitis (ABS) Treatment Options:

• Levofloxacin: 750 mg orally once daily for 5 days or 500 mg orally once daily for 10 to 14 days 2
• Moxifloxacin: indicated for the treatment of acute bacterial sinusitis (ABS) caused by susceptible isolates of Streptococcus pneumoniae, Haemophilus influenzae, or Moraxella catarrhalis 3

Key Points:

• Levofloxacin has been shown to be effective in treating ABS with clinical success rates of 91.4% and 88.6% for the 5-day and 10-14 day regimens, respectively.
• Moxifloxacin is also an option for treating ABS, but should be reserved for patients with no alternative treatment options due to the potential for serious adverse reactions.

From the Research

Acute Sinus Infection Antibiotic Choices

• The primary bacterial species implicated in acute sinusitis are Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis in children 4.
• For adults, therapy may be initiated with high-dose amoxicillin or amoxicillin-clavulanate, with alternatives including cefuroxime, cefpodoxime, or cefdinir 4.
• In cases of serious drug allergy, clarithromycin or azithromycin may be prescribed 4.
• Other options for acute sinusitis treatment include levofloxacin, which has been shown to be as effective and better tolerated than amoxicillin-clavulanate 5.
• Moxifloxacin has also been found to be as effective and safe as amoxicillin/clavulanate in the treatment of acute sinusitis, with more rapid symptomatic relief 6.

Duration of Antibiotic Therapy

• The optimal duration of therapy is unknown, but some recommend treatment until the patient becomes free of symptoms and then for an additional 7 days 4.
• Short-course antibiotic therapy (less than or equal to 5 days) may have equivalent or superior efficacy compared to traditional longer therapies (10-14 days) 7.
• A 5-day course of antibacterial therapy may be sufficient for uncomplicated acute maxillary sinusitis in adults, but further research is needed in children and in adult patients with frontal, ethmoidal, and sphenoidal sinusitis 7.

Tissue and Serum Distribution of Antibiotics

• Amoxicillin/clavulanate has been found to distribute well in ENT tissues, with tissue levels higher than the Minimum Inhibitory Concentration (MIC) for common causative pathogens of sinus bacterial infections 8.
• A dose of 1 g twice a day of amoxicillin/clavulanate may be clinically effective even in patients suffering from acute episodes of chronic rhinosinusitis 8.