What is the evidence for using antibiotics for acute bacterial sinusitis?

From the Guidelines

Antibiotics should only be considered for acute bacterial sinusitis if symptoms are severe, persist beyond 10 days without improvement, or worsen after initial improvement, and when used, a 5-day course is recommended to decrease adverse events. The evidence for using antibiotics in sinusitis is limited, and they are generally not recommended for most cases of acute sinusitis 1. According to a recent meta-analysis, there is no difference in clinical success among patients receiving short-course (3-7 days) versus long-course (6-10 days) therapy for acute bacterial sinusitis 1.

Key Considerations

• Most sinusitis cases (90-98%) are viral in origin and resolve spontaneously within 7-10 days with supportive care like nasal saline irrigation, intranasal corticosteroids, and analgesics 1.
• Bacterial sinusitis should be suspected when symptoms persist beyond 10 days, are unusually severe, or show a "double-worsening" pattern where symptoms improve initially then worsen again 1.
• When antibiotics are indicated, amoxicillin is typically the first-line choice, with amoxicillin-clavulanate as an alternative for suspected resistant bacteria, and doxycycline or levofloxacin for penicillin-allergic patients 1.
• A 5-day course of antibiotics is recommended to decrease adverse events, as it has been shown to have equal efficacy and fewer adverse effects compared to a 10-day regimen 1.

Management Strategies

• Watchful waiting (without antibiotic therapy) is recommended as initial management for all patients with uncomplicated acute bacterial sinusitis, regardless of severity 1.
• Adjunctive therapy, such as intranasal saline irrigation or intranasal corticosteroids, has been shown to alleviate symptoms and potentially decrease antibiotic use 1.
• Patients who are seriously ill, who deteriorate clinically despite antibiotic therapy, or who have recurrent episodes should be referred to a specialist 1.

From the FDA Drug Label

14 CLINICAL STUDIES

14.1 Acute Bacterial Sinusitis In a controlled double-blind study conducted in the U.S., moxifloxacin hydrochloride tablets (400 mg once daily for ten days) were compared with cefuroxime axetil (250 mg twice daily for ten days) for the treatment of acute bacterial sinusitis. The trial included 457 patients valid for the efficacy analysis Clinical success (cure plus improvement) at the 7 to 21 day post-therapy test of cure visit was 90% for moxifloxacin hydrochloride and 89% for cefuroxime. An additional non-comparative study was conducted to gather bacteriological data and to evaluate microbiological eradication in adult patients treated with moxifloxacin 400 mg once daily for seven days All patients (n = 336) underwent antral puncture in this study. Clinical success rates and eradication/presumed eradication rates at the 21 to 37 day follow-up visit were 97% (29 out of 30) for Streptococcus pneumoniae, 83% (15 out of 18) for Moraxella catarrhalis, and 80% (24 out of 30) for Haemophilus influenzae.

The evidence for using antibiotics for acute bacterial sinusitis includes:

• Clinical success rates: 90% for moxifloxacin hydrochloride and 89% for cefuroxime axetil in a controlled double-blind study 2
• Eradication/presumed eradication rates: 97% for Streptococcus pneumoniae, 83% for Moraxella catarrhalis, and 80% for Haemophilus influenzae in a non-comparative study 2 Key points:
• Moxifloxacin hydrochloride is effective in treating acute bacterial sinusitis caused by susceptible isolates of Streptococcus pneumoniae, Haemophilus influenzae, or Moraxella catarrhalis
• The use of moxifloxacin hydrochloride should be reserved for patients who have no alternative treatment options, due to the potential for serious adverse reactions 2

From the Research

Diagnosis and Treatment of Acute Bacterial Sinusitis

• Acute bacterial sinusitis (ABS) is a common problem in both children and adults, with three clinical presentations: onset with persistent symptoms, onset with severe symptoms, and onset with worsening symptoms 3.
• The diagnosis of ABS is often difficult to attain, and images are necessary to confirm the presence of acute sinusitis in older children and adults 3.
• The predominant bacterial species implicated in acute sinusitis are Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis in children 3, 4.
• Antibiotics are effective in the treatment of ABS, with high-dose amoxicillin or amoxicillin-clavulanate as the initial therapy 3, 4.
• Alternatives to amoxicillin include cefuroxime, cefpodoxime, or cefdinir, while clarithromycin or azithromycin may be prescribed in cases of serious drug allergy 3.

Duration of Antibiotic Therapy

• The optimal duration of antibiotic therapy for ABS is unknown, with some recommending treatment until the patient becomes free of symptoms and then for an additional 7 days 3.
• A meta-analysis suggests that short-course antibiotic treatment (up to 7 days) has similar effectiveness to longer-course treatment (6-10 days) for patients with acute uncomplicated bacterial sinusitis 5.
• Short-course antibiotic treatment may lead to fewer adverse events, better patient compliance, lower rates of resistance development, and fewer costs 5.

Effectiveness of High-Dose vs Standard-Dose Amoxicillin

• 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 6.
• The results of this trial suggest that high-dose amoxicillin plus clavulanate may not be superior to standard-dose amoxicillin plus clavulanate in adults with acute bacterial sinusitis 6.

Current Issues in Diagnosis and Management

• Acute bacterial rhinosinusitis is a common infection in children, and early, effective antibacterial therapy is essential to shorten the duration of infection and illness 4.
• The signs and symptoms of acute bacterial rhinosinusitis are similar to those of viral upper respiratory tract infection, making diagnosis a clinical challenge 4.
• Amoxicillin is customarily used as first-line therapy for uncomplicated acute bacterial rhinosinusitis, with second- or third-generation oral cephalosporins as alternatives for patients allergic to amoxicillin 4.
• Supportive care, including saline irrigation, nasal steroids or antihistamines, and decongestants, may help reduce the severity of symptoms 7.