What is the recommended antibiotic for a bacterial sinus infection?

From the Guidelines

Amoxicillin is the recommended first-line antibiotic for treating bacterial sinus infections, typically prescribed at 500 mg three times daily or 875 mg twice daily for 5-10 days. This recommendation is based on the clinical practice guideline update for adult sinusitis, which suggests that amoxicillin with or without clavulanate should be prescribed as first-line therapy for most adults 1. For patients allergic to penicillin, alternatives include doxycycline (100 mg twice daily) or a fluoroquinolone like levofloxacin (750 mg once daily). If the infection is severe or doesn't respond to initial treatment, amoxicillin-clavulanate (875/125 mg twice daily) may be prescribed instead, as it covers a broader spectrum of bacteria including those that produce beta-lactamase.

Some key points to consider when treating bacterial sinus infections include:

• Completing the full course of antibiotics even if symptoms improve
• Staying hydrated to help thin out mucus
• Using saline nasal irrigation to help clear mucus
• Being aware of the potential for antibiotic resistance, particularly in patients who have recently taken antibiotics or have attended childcare
• Considering alternative treatments for patients with severe or complicated infections, such as intravenous ceftriaxone (50 mg per kg once) for children who are vomiting or unable to take oral medications 1.

It's also important to note that the microbiology of acute bacterial sinusitis can vary, with Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis being common causes 1. However, the most recent and highest quality study recommends amoxicillin as the first-line treatment 1.

From the FDA Drug Label

For the 594 patients analyzed in the modified intent to treat analysis at the Day 10 visit, the clinical cure rate for 3 days of azithromycin was 88% (268/303) compared to 85% (248/291) for 10 days of amoxicillin/clavulanate For the 586 patients analyzed in the modified intent to treat analysis at the Day 28 visit, the clinical cure rate for 3 days of azithromycin was 71.5% (213/298) compared to 71.5% (206/288), with a 97.5% confidence interval of –8.4 to 8. 3, for 10 days of amoxicillin/clavulanate Clinical Success Rates of Azithromycin (500 mg per day for 3 Days) Pathogen Day 7 Day 28 S pneumoniae 23/26 (88%) 21/25 (84%) H. influenzae 28/32 (87%) 24/32 (75%) M. catarrhalis 14/15 (93%) 13/15 (87%)

The recommended antibiotic for a bacterial sinus infection is azithromycin. Key points to consider:

• Clinical cure rates: Azithromycin has been shown to have clinical cure rates of 88% at Day 10 and 71.5% at Day 28.
• Comparison to amoxicillin/clavulanate: Azithromycin has been compared to amoxicillin/clavulanate, with similar clinical cure rates at Day 28.
• Pathogen-specific success rates: Azithromycin has been shown to be effective against common pathogens such as S. pneumoniae, H. influenzae, and M. catarrhalis, with clinical success rates ranging from 75% to 93% at Day 28 2.

From the Research

Recommended Antibiotics for Bacterial Sinus Infection

• Amoxicillin or amoxicillin-clavulanate are commonly prescribed for the treatment of acute bacterial sinusitis 3
• For penicillin-allergic patients or those unresponsive to amoxicillin, alternatives include cefuroxime, cefpodoxime, or cefdinir 3
• In cases of serious drug allergy, clarithromycin or azithromycin may be prescribed 3

Dosage and Duration of Therapy

• High-dose amoxicillin or amoxicillin-clavulanate may be initiated for the treatment of acute bacterial sinusitis 3, 4, 5
• 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 3
• A short course (5 days) of gatifloxacin therapy was associated with comparable clinical cure rates and tolerability to those of standard 10-day therapy with gatifloxacin or amoxicillin/clavulanate 6

Comparison of Different Antibiotic Regimens

• A randomized clinical trial found that adults treated for clinically diagnosed acute sinusitis did not appear to benefit from taking high-dose compared with standard-dose amoxicillin plus clavulanate 4
• Another study found that adults with clinically diagnosed acute bacterial sinusitis were more likely to improve rapidly when treated with immediate-release high-dose amoxicillin/clavulanate than with standard-dose, but not when treated with extended-release high-dose 5
• Amoxicillin and clavulanate given every 12 hours was found to be as effective and safe as administration every 8 hours for the treatment of acute bacterial maxillary sinusitis 7