How is bronchitis, whether bacterial or viral, typically treated?

Treatment of Bronchitis: Bacterial vs. Viral

Acute bronchitis is predominantly viral in origin (>90% of cases) and does not require antibiotic therapy, while chronic bronchitis exacerbations may benefit from antibiotics only when specific criteria are met.

Acute Bronchitis

Diagnosis and Etiology

• Acute bronchitis is characterized by cough lasting up to 3 weeks, with or without sputum production 1
• Over 90% of acute bronchitis cases have a nonbacterial cause, primarily viral infections 2
• Common viral causes include:
  • Influenza A and B
  • Parainfluenza virus
  • Respiratory syncytial virus (RSV)
  • Coronavirus
  • Adenovirus
  • Rhinovirus 2
• Only a small percentage (5-10%) of cases are caused by bacterial pathogens such as:
  • Bordetella pertussis
  • Mycoplasma pneumoniae
  • Chlamydia pneumoniae 2

Treatment Recommendations

1. No routine antibiotics for acute bronchitis 1, 2

   • Antibiotics do not significantly improve outcomes
   • May only decrease cough duration by approximately 0.5 days 3
   • Expose patients to unnecessary adverse effects

2. Specific exceptions for antibiotic use:

   • Suspected or confirmed pertussis (macrolides such as erythromycin)
   • Patients with underlying pulmonary disease at high risk for complications 1

3. Symptomatic management:

   • Short-term cough suppressants (codeine or dextromethorphan) may provide relief 1
   • Honey (one teaspoon) for adults and children >1 year 1
   • Adequate hydration
   • Avoidance of respiratory irritants 1

Chronic Bronchitis

Diagnosis and Classification

• Defined as daily productive cough for at least 3 consecutive months, present for at least 2 consecutive years 1
• Classified into three stages:
  1. Simple chronic bronchitis
  2. Obstructive chronic bronchitis
  3. Obstructive chronic bronchitis with respiratory insufficiency 2, 1

Treatment of Stable Chronic Bronchitis

1. Smoking cessation - most effective intervention, resolves cough in 90% of patients 1
2. Avoidance of respiratory irritants 1
3. Symptomatic management:
   • Short-acting β-agonists
   • Ipratropium bromide
   • Long-acting β-agonist with inhaled corticosteroids (ICS)
   • ICS therapy 1

Treatment of Acute Exacerbations of Chronic Bronchitis

When to Use Antibiotics

Antibiotic therapy is recommended when:

1. For simple chronic bronchitis:

   • Only if fever (>38°C) persists for more than 3 days 2

2. For obstructive chronic bronchitis:

   • When at least two of the three Anthonisen criteria are present:
     • Increased sputum volume
     • Increased sputum purulence
     • Increased dyspnea 2
   • Or if fever (>38°C) persists for more than 3 days 2

3. For obstructive chronic bronchitis with respiratory insufficiency:

   • Immediate antibiotic therapy is recommended 2

Antibiotic Selection

1. First-line antibiotics (for infrequent exacerbations, FEV₁ ≥35%):

   • Amoxicillin (reference compound)
   • First-generation cephalosporins
   • Macrolides, pristinamycin, or doxycycline (if allergic to beta-lactams) 2

2. Second-line antibiotics (for frequent exacerbations or FEV₁ <35%):

   • Amoxicillin-clavulanate (reference compound)
   • Second/third-generation oral cephalosporins
   • Respiratory fluoroquinolones (levofloxacin, moxifloxacin) 2, 4

Common Pitfalls and Considerations

1. Misdiagnosis:

   • Up to one-third of patients diagnosed with acute bronchitis may actually have asthma or chronic bronchitis 1
   • Rule out pneumonia if any of these are present: heart rate >100 beats/min, respiratory rate >24 breaths/min, oral temperature >38°C, or focal chest findings 1

2. Antibiotic overuse:

   • 65-80% of acute bronchitis patients receive antibiotics despite evidence against routine use 1
   • Contributes to antibiotic resistance

3. Ineffective treatments:

   • Expectorants have not been proven effective for either acute or chronic bronchitis 1
   • Theophylline is contraindicated during acute exacerbations of chronic bronchitis 1

4. Patient education:

   • Inform patients about typical cough duration (2-3 weeks)
   • Explain the viral nature of most cases
   • Discuss risks of unnecessary antibiotic use 1

By following these evidence-based guidelines, clinicians can provide appropriate care for patients with bronchitis while avoiding unnecessary antibiotic use and its associated risks.