What is the first line treatment for bacterial bronchitis and pneumonia?

First-Line Treatment for Bacterial Bronchitis and Pneumonia

Amoxicillin is the first-line treatment for both bacterial bronchitis and pneumonia, with specific regimens based on patient age, disease severity, and suspected pathogens. 1

Bacterial Bronchitis Treatment

Simple Acute Bronchitis

• In otherwise healthy adults, immediate antibiotic therapy is generally not recommended for simple acute bronchitis, even with fever present, as most cases are viral in origin 1
• Antibiotic therapy should only be initiated if fever (>38°C) persists for more than 3 days 1

Exacerbation of Chronic Bronchitis

• For patients with infrequent exacerbations and FEV1 >35%, amoxicillin remains the reference treatment 1
• Alternative first-line options for patients with beta-lactam allergies include macrolides, pristinamycin, or doxycycline 1
• For patients with chronic obstructive bronchitis (FEV1 between 35-80%), immediate antibiotic therapy is only recommended if at least two of the three Anthonisen criteria are present (increased sputum volume, increased sputum purulence, increased dyspnea) 1

Second-Line Options for Bronchitis

• Amoxicillin-clavulanate is the reference second-line treatment for patients with:
  • Failure of first-line treatment
  • Frequent exacerbations (≥4 per year)
  • Baseline FEV1 <35% 1
• Alternative second-line options include:
  • Second-generation cephalosporins (cefuroxime-axetil)
  • Third-generation cephalosporins (cefpodoxime-proxetil)
  • Respiratory fluoroquinolones (levofloxacin, moxifloxacin) 1

Community-Acquired Pneumonia Treatment

Adults

• Amoxicillin (3 g/day) is the reference treatment for pneumococcal pneumonia in adults without risk factors 1
• For patients with risk factors or suspected atypical pathogens, treatment options include:
  • Amoxicillin-clavulanate
  • Parenteral 2nd or 3rd generation cephalosporins
  • Respiratory fluoroquinolones active against S. pneumoniae 1, 2
• Levofloxacin is FDA-approved for community-acquired pneumonia caused by multiple pathogens including S. pneumoniae, H. influenzae, M. pneumoniae, and C. pneumoniae 2

Children

• For children under 3 years, amoxicillin (80-100 mg/kg/day in three daily doses) is the initial treatment of choice 1, 3
• For children over 3 years:
  • If pneumococcal infection is suspected, amoxicillin is the reference treatment
  • If atypical pathogens (Mycoplasma pneumoniae, Chlamydia pneumoniae) are suspected, macrolides are recommended 1
• In children under 5 years with insufficient H. influenzae type b vaccination or coexistent purulent acute otitis media, amoxicillin-clavulanate (80 mg/kg/day amoxicillin component) is justified 1, 3

Treatment Duration

• For bronchitis exacerbations: 5-8 days 1
• For community-acquired pneumonia in adults: 7-14 days 1, 2
• For community-acquired pneumonia in children: 5-8 days 1

Special Considerations

Atypical Pathogens

• For suspected atypical pathogens (Mycoplasma, Chlamydia, Legionella):
  • Macrolides (clarithromycin, azithromycin) are the first-line treatment 4, 5, 6
  • Respiratory fluoroquinolones are alternatives in adults 2

Treatment Failure

• Therapeutic efficacy should be assessed within 48-72 hours after initiating treatment 1
• Treatment should not be changed within the first 72 hours unless the patient's clinical condition worsens 1
• Failure of amoxicillin treatment may indicate:
  • Infection with beta-lactamase producing organisms
  • Atypical pathogens
  • Incorrect initial diagnosis 1, 3

Common Pitfalls

• Treating all bronchitis cases with antibiotics despite most being viral in origin 1, 7
• Using fluoroquinolones as first-line therapy when narrower-spectrum antibiotics would be appropriate 1
• Failing to consider atypical pathogens when initial therapy fails 6
• Using antibiotics with poor activity against S. pneumoniae (such as ciprofloxacin or cefixime) for respiratory infections 1