From the Guidelines
For bacterial bronchitis secondary to influenza, co-amoxiclav 625 mg tds PO is the preferred antibiotic of choice, as it effectively targets the most common bacterial pathogens, including Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis, as recommended by 1 and 1. This recommendation is based on the guidelines for the clinical management of patients with an influenza-like illness during an influenza pandemic, which suggest that co-amoxiclav or a tetracycline, such as doxycycline, should be the preferred choice for non-pneumonic bronchial complications, including exacerbations of COPD and acute bronchitis, requiring antibiotic therapy 1. The use of co-amoxiclav is supported by its ability to overcome beta-lactamase resistance, which is common among the bacterial pathogens that cause secondary infections following influenza 1. For patients with penicillin allergies, alternatives include doxycycline (200 mg stat and 100 mg od PO) or a fluoroquinolone with enhanced pneumococcal activity, such as levofloxacin (500 mg od PO) or moxifloxacin (400 mg od PO), as recommended by 1 and 1. It is essential to note that macrolides, such as erythromycin or clarithromycin, are not the first-line choice due to increasing resistance patterns, but may be considered as an alternative in certain circumstances, as suggested by 1 and 1. When treating bacterial bronchitis secondary to influenza, it is crucial to also continue supportive care with adequate hydration, rest, and antipyretics as needed, and patients should complete the full course of antibiotics even if symptoms improve before completion to prevent recurrence and antibiotic resistance, as recommended by 1.
From the FDA Drug Label
Adult PatientsAcute Bacterial Exacerbations of Chronic Obstructive Pulmonary Disease In a randomized, double-blind controlled clinical trial of acute exacerbation of chronic bronchitis (AECB), azithromycin (500 mg once daily for 3 days) was compared with clarithromycin (500 mg twice daily for 10 days).
The primary endpoint of this trial was the clinical cure rate at Day 21 to 24 For the 304 patients analyzed in the modified intent to treat analysis at the Day 21 to 24 visit, the clinical cure rate for 3 days of azithromycin was 85% (125/147) compared to 82% (129/157) for 10 days of clarithromycin
The ABX of choice for bacterial bronchitis secondary to influenza is azithromycin.
- Key points:
- Clinical cure rate: 85% for azithromycin
- Treatment duration: 3 days
- Dosage: 500 mg once daily 2
From the Research
ABX of Choice for Bacterial Bronchitis Secondary to Influenza
- The choice of antibiotic for bacterial bronchitis secondary to influenza is not explicitly stated in the provided studies, but some studies suggest that antibiotics may be over-prescribed in patients with influenza or influenza-like illness 3, 4.
- A study published in 2018 found that azithromycin is non-inferior to amoxicillin-clavulanate for resolving exacerbations in children with non-severe bronchiectasis 5.
- Another study published in 2017 found that antibiotics may have a modest beneficial effect in some patients with acute bronchitis, but the magnitude of this benefit needs to be considered in the broader context of potential side effects and increased resistance to respiratory pathogens 6.
- A study published in 2006 suggests that neuraminidase inhibitors may be of interest for the management of influenza-infected patients, as they can decrease the risk of bacterial complications and the use of antibiotics 4.
- The bacteria involved in bacterial infections secondary to influenza include Streptococcus pneumoniae, Haemophilus influenzae, and Staphylococcus aureus, among others 7, 4.
Considerations for Antibiotic Use
- Antibiotic overuse remains widespread in the treatment of outpatient acute respiratory infections, including among patients with laboratory-confirmed influenza 3.
- The use of antibiotics in patients with influenza or influenza-like illness without signs of bacterial infection is not supported by evidence 3, 4.
- The choice of antibiotic should be guided by the severity of the infection, the presence of underlying conditions, and the potential for antibiotic resistance 7, 5, 6.