Recommended Antibiotic for Acute Exacerbation of Chronic Bronchitis
For an adult patient with acute exacerbation of chronic bronchitis without recent antibiotic use and no penicillin allergy, co-amoxiclav (amoxicillin-clavulanate) is the recommended first-line antibiotic. 1, 2
Risk Stratification Determines Antibiotic Choice
The selection of antibiotics must be guided by disease severity and risk factors for resistant organisms, particularly Pseudomonas aeruginosa. 1
For Patients WITHOUT Risk Factors for P. aeruginosa:
Co-amoxiclav (amoxicillin-clavulanate) is the preferred agent for moderate-to-severe exacerbations requiring hospitalization. 1, 2 This provides optimal coverage against the three most common pathogens: Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. 3, 4, 5
- Dosing: 625 mg three times daily orally 2
- Alternative options include levofloxacin or moxifloxacin, which offer better coverage against S. pneumoniae than ciprofloxacin 1
- For mild exacerbations managed at home, amoxicillin or tetracycline may suffice 1
For Patients WITH Risk Factors for P. aeruginosa:
Ciprofloxacin is the antibiotic of choice when oral therapy is appropriate. 1 Risk factors include:
Recent hospitalization or antibiotic use
Structural lung disease (bronchiectasis) 1
Alternative oral option: Levofloxacin 750 mg once daily or 500 mg twice daily 1
For parenteral therapy: Ciprofloxacin or a β-lactam with antipseudomonal activity (cefepime, piperacillin-tazobactam, or carbapenem), with optional addition of aminoglycosides 1
Treatment Duration and Route
Standard antibiotic courses should be 7-10 days. 1, 2 Shorter 5-day courses with levofloxacin or moxifloxacin have demonstrated equivalent efficacy to 10-day β-lactam regimens in some trials. 1
Switch from intravenous to oral therapy by day 3 if the patient is clinically stable and able to tolerate oral intake. 1 The oral route is preferred whenever feasible. 1
Critical Pitfalls to Avoid
Do not use fluoroquinolones as routine first-line therapy in uncomplicated cases without risk factors, as this promotes resistance and reserves these agents for more complex situations. 2, 4 The European Respiratory Society guidelines emphasize that co-amoxiclav remains the reference standard for most exacerbations. 1, 3
Reassess patients who fail to respond within 5-7 days. 7 Non-response may indicate:
- Infection with P. aeruginosa, Staphylococcus aureus (including MRSA), or other non-fermenters 1
- Non-infectious causes (pulmonary embolism, heart failure, inadequate bronchodilator therapy) 1
- Need for sputum culture and sensitivity testing 1
In countries with high rates of penicillin-resistant S. pneumoniae, increase amoxicillin dosing to 1 gram every 8 hours. 1 However, amoxicillin-clavulanate at standard doses typically provides adequate coverage due to the clavulanate component. 3
Special Considerations
Obtain sputum culture before initiating antibiotics in hospitalized patients or those with frequent exacerbations, though empiric therapy should not be delayed. 1, 8 This guides subsequent therapy if initial treatment fails. 1
Antibiotic therapy should be reserved for patients with at least one cardinal symptom (increased dyspnea, sputum volume, or sputum purulence) plus at least one risk factor (age ≥65 years, FEV1 <50%, ≥4 exacerbations per year, or comorbidities). 5 Not all exacerbations require antibiotics, as approximately 20% are non-infectious. 5