What is the best antibiotic for acute bacterial sinusitis (ABS)?

From the Guidelines

Amoxicillin alone or in combination with clavulanate is the first-line antibiotic choice for acute bacterial sinusitis. This recommendation is based on the American Academy of Pediatrics (AAP) guideline on diagnosis and management of acute bacterial sinusitis in children one to 18 years of age 1. The guideline suggests that antibiotics should be prescribed in children with severe, worsening, or persistent acute bacterial sinusitis.

Key Points to Consider

• Amoxicillin alone or in combination with clavulanate is the preferred first-line treatment due to its effectiveness against common sinusitis pathogens, including Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis.
• For children who are vomiting, cannot take oral medications, or are not likely to take the initial antibiotic doses as prescribed, intravenous or intramuscular ceftriaxone (Rocephin) can be given as an alternative 1.
• Children with hypersensitivity to amoxicillin can be treated with cefdinir (Omnicef), cefuroxime (Ceftin), or cefpodoxime 1.

Treatment Considerations

• Outpatient observation for three days is also an option in children with persistent illness, allowing for a trial of symptomatic treatment before initiating antibiotics 1.
• After clinical improvement, the treatment can be changed to oral therapy, ensuring that the patient completes the full course of antibiotics even if symptoms improve before finishing treatment.
• Symptomatic measures such as saline nasal irrigation, intranasal corticosteroids, and analgesics should accompany antibiotic treatment to help manage symptoms and support recovery.

From the FDA Drug Label

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)

The best antibiotic for acute bacterial sinusitis is levofloxacin, with a 5-day regimen of 750 mg by mouth once daily showing a 91.4% clinical success rate, and a 10-14 day regimen of 500 mg by mouth once daily showing an 88.6% clinical success rate 2.

• Key points:
  • Levofloxacin is approved for the treatment of acute bacterial sinusitis
  • Two regimens are available: 750 mg for 5 days or 500 mg for 10-14 days
  • Clinical success rates are high for both regimens, with the 5-day regimen showing a slightly higher success rate.

From the Research

Antibiotic Treatment for Acute Bacterial Sinusitis

• The most effective antibiotic treatment for acute bacterial sinusitis is a topic of ongoing research, with various studies yielding different results 3, 4, 5, 6, 7.
• Amoxicillin with clavulanate is a commonly recommended treatment for acute bacterial sinusitis in adults and children 3, 4, 5, 7.
• High-dose amoxicillin with clavulanate may be more effective than standard-dose treatment in some cases, but the evidence is not consistent 3, 4, 5.
• For children, amoxicillin-clavulanate at a standard dose of 45 mg/kg/day orally is often recommended, while high-dose amoxicillin-clavulanate (90 mg/kg/day) may be used for severe cases or when antibiotic resistance is suspected 5.
• Alternative antibiotics, such as doxycycline or respiratory fluoroquinolones, may be used in patients with beta-lactam allergies 6.

Comparison of Antibiotic Treatments

• A study comparing high-dose and standard-dose amoxicillin with clavulanate found that high-dose treatment was more effective in adults with acute bacterial sinusitis, but with a higher risk of severe diarrhea 3.
• Another study found no significant difference in efficacy between high-dose and standard-dose amoxicillin with clavulanate in adults with acute bacterial sinusitis 4.
• A review of studies on acute bacterial sinusitis in children found that amoxicillin-clavulanate was effective in treating the condition, with high-dose treatment being more effective in some cases 5, 7.

Considerations for Treatment

• The diagnosis of acute bacterial sinusitis is mainly clinical, and antibiotic treatment should be considered for patients with severe symptoms or those who do not improve with supportive care 6.
• Supportive care, including saline irrigation, nasal steroids or antihistamines, and decongestants, may help reduce the severity of symptoms 6.
• Complications of rhinosinusitis, such as orbital cellulitis or meningitis, are rare but may require more aggressive treatment, including computed tomography and referral to an otolaryngologist 6.