Treatment of Bacterial Bronchitis: Antibiotic Selection, Dosage, and Duration

For bacterial bronchitis, amoxicillin 500 mg three times daily for 5 days is the recommended first-line antibiotic treatment. 1

First-Line Treatment Options

Amoxicillin 500 mg three times daily for 5 days is the standard first-line treatment for bacterial bronchitis with clinical signs of bacterial infection (increased sputum purulence plus increased dyspnea and/or increased sputum volume) 1
For patients with beta-lactamase producing organisms, amoxicillin-clavulanate 625 mg three times daily for 5 days is recommended 1
The treatment duration should be limited to 5 days as longer durations have not shown additional benefits in uncomplicated bacterial bronchitis 1

Doxycycline 100 mg twice daily for 5 days is an effective alternative for patients with penicillin allergy 1
Clarithromycin 500 mg twice daily for 5-7 days can be used as an alternative, particularly when atypical pathogens are suspected 2
Azithromycin 500 mg on day 1, followed by 250 mg daily for days 2-5 is another alternative with good compliance due to once-daily dosing 3, 4

Common bacterial pathogens in bronchitis include:

Haemophilus influenzae: Amoxicillin 500 mg three times daily (for beta-lactamase negative strains) or amoxicillin-clavulanate 625 mg three times daily (for beta-lactamase positive strains) for 5 days 1
Streptococcus pneumoniae: Amoxicillin 500 mg three times daily for 5 days 1
Moraxella catarrhalis: Amoxicillin-clavulanate 625 mg three times daily for 5 days 1

For patients with chronic obstructive pulmonary disease (COPD) exacerbations, antibiotic therapy is indicated when at least two of the three Anthonisen criteria are present: increased sputum volume, increased sputum purulence, and increased dyspnea 1
In simple chronic bronchitis without obstruction, immediate antibiotic therapy is not recommended unless fever persists for more than 3 days 1
For patients with obstructive chronic bronchitis with chronic respiratory insufficiency, immediate antibiotic therapy is recommended 1

Acute uncomplicated bronchitis is typically a self-limited viral infection and antibiotics should not be initiated unless there are clear signs of bacterial infection 1
Purulent sputum alone is not sufficient to indicate bacterial infection or need for antibiotics 1
If a patient is not improving with appropriate antibiotics, reassess for other causes rather than extending antibiotic duration 1
These recommendations may not apply to patients with complicated anatomy (such as bronchiectasis) or recent history of resistant bacterial infections 1
For bronchiectasis, longer courses (14 days) are typically recommended, especially for Pseudomonas aeruginosa infections 1

Patients should show clinical improvement within 2-3 days of starting appropriate antibiotic therapy 1
If symptoms persist beyond this timeframe, consider reevaluation for alternative diagnoses or resistant organisms 1