What are the recommended antibiotics for bacterial sinusitis?

From the Guidelines

Amoxicillin is the first-line antibiotic treatment for bacterial sinusitis, typically prescribed at a dose of 45 mg/kg per day in 2 divided doses for children, or 500 mg three times daily or 875 mg twice daily for 5-10 days for adults. For patients with penicillin allergies, alternatives include doxycycline (100 mg twice daily), trimethoprim-sulfamethoxazole (one double-strength tablet twice daily), or a respiratory fluoroquinolone like levofloxacin (750 mg once daily) 1. If symptoms don't improve within 3-5 days or if the patient has risk factors like recent antibiotic use or severe symptoms, amoxicillin-clavulanate (875/125 mg twice daily) is recommended to cover beta-lactamase producing bacteria 1. Patients should complete the full course of antibiotics even if symptoms improve, stay hydrated, use saline nasal irrigation, and consider over-the-counter pain relievers and decongestants for symptom relief.

Some key points to consider when treating bacterial sinusitis include:

• The use of narrow-spectrum antibiotics, such as amoxicillin, to reduce the risk of antibiotic resistance 1
• The importance of completing the full course of antibiotics, even if symptoms improve, to ensure that the infection is fully cleared 1
• The use of adjunctive therapies, such as saline nasal irrigation and decongestants, to help alleviate symptoms and promote mucous clearance 1
• The need for patient education on the rationale for management and the importance of seeking medical attention if symptoms worsen or do not improve with treatment 1

It's also important to note that acute uncomplicated rhinosinusitis is a self-limited infection that usually resolves without antibiotics, even in patients with a bacterial cause, and that symptomatic treatment or reassurance is the preferred initial approach for patients with mild symptoms 1. However, patients with severe or persistent moderate symptoms and specific findings of bacterial rhinosinusitis should be treated with antibiotics.

In terms of specific patient populations, children with uncomplicated acute bacterial sinusitis can be treated with amoxicillin at a dose of 45 mg/kg per day in 2 divided doses, while those with moderate to severe illness or risk factors for resistance may require high-dose amoxicillin-clavulanate (80–90 mg/kg per day of the amoxicillin component with 6.4 mg/kg per day of clavulanate in 2 divided doses) 1. Adults with acute bacterial sinusitis can be treated with amoxicillin at a dose of 500 mg three times daily or 875 mg twice daily for 5-10 days, or with alternative antibiotics such as doxycycline or trimethoprim-sulfamethoxazole if they have a penicillin allergy 1.

From the FDA Drug Label

1. 4 Acute Bacterial Sinusitis: 5 Day and 10 to 14 Day Treatment Regimens Levofloxacin tablets are indicated for the treatment of acute bacterial sinusitis due to Streptococcus pneumoniae, Haemophilus influenzae, or Moraxella catarrhalis 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)

Levofloxacin is indicated for the treatment of acute bacterial sinusitis due to Streptococcus pneumoniae, Haemophilus influenzae, or Moraxella catarrhalis.

• The recommended treatment regimens are:
  • 750 mg by mouth once daily for 5 days
  • 500 mg by mouth once daily for 10 to 14 days Clinical success rates were 91.4% for the 5-day regimen and 88.6% for the 10-day regimen 2.

From the Research

Antibiotics for Bacterial Sinusitis

• The use of antibiotics for bacterial sinusitis is a common practice, with the goal of reducing symptoms and preventing complications 3.
• The most common bacterial species implicated in acute sinusitis are Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis in children, and the prevalence of penicillin-resistant S. pneumoniae, and beta-lactamase-producing H. influenzae and M. catarrhalis has been increasing 3.
• High-dose amoxicillin or amoxicillin-clavulanate are often used as the first line of treatment, with alternatives including cefuroxime, cefpodoxime, or cefdinir 3.
• A study comparing high-dose versus standard-dose amoxicillin/clavulanate for clinically-diagnosed acute bacterial sinusitis found that adults with clinically diagnosed acute bacterial sinusitis were more likely to improve rapidly when treated with high-dose amoxicillin/clavulanate, but were also more likely to suffer severe diarrhea 4.

Treatment Duration and Effectiveness

• The optimal duration of therapy for acute bacterial sinusitis is unknown, but some studies suggest that short-course therapy (less than or equal to 5 days) may have equivalent or superior efficacy compared to traditional longer therapies (10-14 days) 5.
• A study comparing cefdinir and amoxicillin-clavulanate for the treatment of acute community-acquired bacterial sinusitis found that cefdinir was as effective clinically as amoxicillin-clavulanate, with similar microbiologic eradication rates and fewer adverse events requiring treatment discontinuation 6.
• Another study comparing azithromycin and amoxicillin/clavulanate for the treatment of acute sinusitis found that a 3-day course of azithromycin was as effective and well tolerated as a 10-day course of amoxicillin/clavulanate, with a significantly faster resolution of signs and symptoms of sinusitis 7.

Antibiotic Options

• Amoxicillin-clavulanate is a commonly used antibiotic for the treatment of acute bacterial sinusitis, but alternatives such as cefdinir, cefuroxime, and azithromycin may be used in certain cases 3, 6, 7.
• The choice of antibiotic should be based on the suspected or confirmed causative organism, as well as the patient's medical history and potential allergies 3.