What antibiotics are effective for treating acute bronchitis in adults?

From the Guidelines

Antibiotics are not recommended for acute bronchitis in otherwise healthy adults. Most cases of acute bronchitis are caused by viral infections, not bacterial ones, making antibiotics ineffective for treatment 1. The condition is typically self-limiting and resolves within 1-3 weeks without specific antibiotic therapy. According to the American College of Physicians and the Centers for Disease Control and Prevention, more than 90% of otherwise healthy patients presenting with an acute cough have a syndrome caused by a virus 1.

Key Points to Consider

• The presence of purulent sputum or a change in its color does not signify bacterial infection; purulence is due to the presence of inflammatory cells or sloughed mucosal epithelial cells 1.
• Acute bronchitis must be distinguished from pneumonia, and for healthy immunocompetent adults younger than 70 years, pneumonia is unlikely in the absence of specific clinical criteria such as tachycardia, tachypnea, fever, and abnormal findings on a chest examination 1.
• Treatment should focus on symptom management with rest, adequate hydration, and over-the-counter medications like acetaminophen or NSAIDs for fever and pain, and cough suppressants if needed.

Exceptions for Antibiotic Use

Antibiotics should only be considered if there are specific indications of bacterial infection, such as in patients with underlying chronic lung disease, immunocompromise, or when symptoms persist beyond 2-3 weeks with purulent sputum. In these select cases, options might include doxycycline, amoxicillin-clavulanate, or azithromycin, but the choice of antibiotic and duration of treatment should be guided by the most recent clinical guidelines and susceptibility patterns 1. Unnecessary antibiotic use contributes to antibiotic resistance, disrupts normal gut flora, and may cause side effects without providing benefit in viral bronchitis cases.

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).

1. 5 Acute Bacterial Exacerbation of Chronic Bronchitis Levofloxacin tablets are indicated for the treatment of acute bacterial exacerbation of chronic bronchitis due to methicillin-susceptible Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae, Haemophilus parainfluenzae, or Moraxella catarrhalis.

Antibiotics covering acute bronchitis in adults include:

• Azithromycin
• Levofloxacin
• Clarithromycin The clinical cure rates for azithromycin were 85% in a clinical trial for acute bacterial exacerbations of chronic bronchitis 2. The approved use of levofloxacin includes the treatment of acute bacterial exacerbation of chronic bronchitis due to certain pathogens, including methicillin-susceptible Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae, Haemophilus parainfluenzae, or Moraxella catarrhalis 3.

From the Research

Antibiotics for Acute Bronchitis in Adults

• The use of antibiotics for acute bronchitis in adults is generally not recommended, as most cases are caused by viruses 4.
• However, in cases where a bacterial infection is suspected, antibiotics such as azithromycin or amoxicillin/clavulanic acid may be prescribed 5, 6, 7, 8.
• Azithromycin has been shown to be effective in treating acute lower respiratory tract infections, including acute bronchitis, with a lower incidence of treatment failure and adverse events compared to amoxicillin or amoxicillin/clavulanic acid 7.
• A study comparing azithromycin and amoxicillin/clavulanic acid in the treatment of acute purulent exacerbation of chronic bronchitis found that amoxicillin/clavulanic acid had a higher efficacy rate and microbiological efficacy compared to azithromycin 8.
• The choice of antibiotic and duration of treatment should be based on the severity of the infection, the presence of underlying health conditions, and the patient's response to treatment 4, 5, 6, 7, 8.

Specific Antibiotics and Their Efficacy

• Azithromycin: effective in treating acute lower respiratory tract infections, including acute bronchitis, with a lower incidence of treatment failure and adverse events compared to amoxicillin or amoxicillin/clavulanic acid 5, 6, 7.
• Amoxicillin/clavulanic acid: effective in treating acute purulent exacerbation of chronic bronchitis, with a higher efficacy rate and microbiological efficacy compared to azithromycin 8.
• Co-amoxiclav: effective in treating acute lower respiratory tract infections, including acute bronchitis, with a similar efficacy rate compared to azithromycin 5.

Considerations for Antibiotic Use

• Antibiotic treatment should only be considered in cases where a bacterial infection is suspected or confirmed 4.
• The use of antibiotics should be guided by the principles of appropriate antibiotic use, including the evaluation of the patient's condition, the selection of the most effective antibiotic, and the monitoring of the patient's response to treatment 4.
• Patient satisfaction with care for acute bronchitis depends most on physician-patient communication rather than on antibiotic treatment 4.