First-Line Treatment for Bacterial Bronchitis
In otherwise healthy adults with acute bronchitis, antibiotics should NOT be prescribed, as bronchitis is predominantly viral (90% of cases) and antibiotics provide no meaningful clinical benefit. 1, 2
When Antibiotics Are NOT Indicated
- Acute bronchitis in healthy adults does not warrant antibiotic therapy, as clinical trials versus placebo have failed to demonstrate benefit (Grade B evidence). 1, 2
- The presence of purulent sputum or change in sputum color (green or yellow) does NOT indicate bacterial infection and should not trigger antibiotic prescription. 2
- Even with cough persisting beyond 10 days, if the patient is otherwise healthy without risk factors, antibiotics remain unjustified. 1
When Antibiotics ARE Indicated
Antibiotics should be reserved for specific high-risk situations:
Patients with Underlying Chronic Obstructive Pulmonary Disease (COPD)
For patients with FEV1 between 35-80%, antibiotics are indicated when at least 2 of 3 Anthonisen criteria are present: 2
- Increased sputum volume
- Increased sputum purulence
- Increased dyspnea
For patients with severe respiratory insufficiency (FEV1 <35%), immediate antibiotic therapy is recommended during any exacerbation. 2
Fever Persistence
- Fever >38.5°C persisting for more than 3 days suggests bacterial superinfection and warrants antibiotic consideration. 1, 2
First-Line Antibiotic Choice (When Indicated)
Amoxicillin is the first-line antibiotic for bacterial bronchitis when treatment is warranted. 2
Dosing and Alternatives
- Amoxicillin: Standard first-line agent 2
- First-generation cephalosporins: Alternative first-line option 2
- For penicillin allergy: Macrolides (azithromycin), pristinamycin, or doxycycline 2
Target Pathogens
The antibiotic selected must cover: 2
- Streptococcus pneumoniae
- Haemophilus influenzae
- Moraxella catarrhalis
Treatment Duration
- 5-8 days is the recommended duration for bacterial bronchitis when antibiotics are used. 1
Second-Line Options (Treatment Failure)
If first-line therapy fails after 72 hours, consider: 2
- Amoxicillin-clavulanate (reference second-line therapy) 2
- Second-generation cephalosporins (cefuroxime-axetil) 2
- Third-generation cephalosporins (cefpodoxime-proxetil, cefotiam-hexetil) 2
- Respiratory fluoroquinolones (levofloxacin, moxifloxacin) for complicated cases 2
Special Populations: Complicated Chronic Bronchitis
For patients with complicated/severe acute exacerbations of chronic bronchitis (≥3 episodes per year, multiple comorbidities, previous treatment failure, or severe obstruction), broader spectrum coverage may be warranted: 3, 4
- Fluoroquinolones should be considered first-line in patients with: 3, 4
- Chronic bronchitis with comorbid illness
- Severe obstruction (FEV1 <50%)
- Age >65 years
- Recurrent exacerbations
Critical Pitfalls to Avoid
- Do NOT prescribe antibiotics for uncomplicated acute bronchitis in healthy adults, even with purulent sputum—this drives antibiotic resistance without clinical benefit. 1, 2
- Do NOT use fluoroquinolones inactive against pneumococci (ofloxacin, ciprofloxacin) or cefixime, as these lack adequate coverage. 2
- Do NOT use cotrimoxazole, which has inconsistent activity against pneumococci and poor benefit/risk ratio. 2
- Do NOT confuse acute bronchitis with pneumonia—pneumonia requires chest X-ray confirmation and different management. 1
- Do NOT assume all cephalosporins are equivalent—first-generation agents have inadequate activity against resistant S. pneumoniae. 5
Evidence Quality Note
The guideline evidence consistently demonstrates that the vast majority of acute bronchitis cases are viral, and the meta-analysis of antibiotic trials shows only a marginal benefit of approximately 0.5 days reduction in symptoms, which does not justify the risks of adverse effects and antibiotic resistance. 6 The strongest evidence supports withholding antibiotics in healthy adults and reserving them strictly for patients with underlying lung disease meeting specific clinical criteria. 1, 2