What is the recommended treatment for a patient with bacterial bronchitis, considering their medical history and potential allergies?

Treatment of Bacterial Bronchitis

Do NOT Prescribe Antibiotics for Uncomplicated Acute Bronchitis

Antibiotics should NOT be prescribed for acute bronchitis in otherwise healthy adults, as they provide minimal benefit (reducing cough by only half a day) while causing significant adverse effects and contributing to antibiotic resistance. 1, 2

• Respiratory viruses cause 89-95% of acute bronchitis cases, making antibiotics completely ineffective in the vast majority of patients 2
• Purulent sputum (even green or yellow) does NOT indicate bacterial infection—it occurs in 89-95% of viral cases and is not an indication for antibiotics 2, 3
• Cough typically lasts 10-14 days after the visit, even without antibiotics, and can persist up to 3 weeks—this duration alone does not justify antibiotic use 2

When to Consider Antibiotics: COPD Exacerbations Only

Limit antibiotic treatment to patients with COPD exacerbations who have clinical signs of bacterial infection, defined as increased sputum purulence PLUS increased dyspnea and/or increased sputum volume (Anthonisen criteria). 1, 2

Patient Stratification for Antibiotic Use:

Uncomplicated COPD patients (FEV1 >50%, no risk factors):

• Use antibiotics only if ≥2 Anthonisen criteria present 2, 3
• Duration: 5 days maximum 1

Complicated COPD patients (FEV1 <50%, age >65, cardiac failure, diabetes, or frequent exacerbations):

• Lower threshold for antibiotics with ≥2 Anthonisen criteria 2, 4
• Duration: 5-7 days 1, 2

Severe COPD with chronic respiratory insufficiency (FEV1 <35%):

• Immediate antibiotic therapy recommended during exacerbations 3, 4
• Duration: 7-10 days 2

First-Line Antibiotic Choices

For uncomplicated COPD exacerbations:

• Amoxicillin 500 mg three times daily for 5 days 3, 5
• Alternative: Doxycycline 100 mg twice daily for 5-7 days 2
• For penicillin allergy: Azithromycin 500 mg day 1, then 250 mg daily days 2-5 2, 6

For complicated COPD exacerbations or treatment failure:

• Amoxicillin-clavulanate 875/125 mg twice daily for 7 days 4, 7
• Alternative: Levofloxacin 750 mg once daily for 5 days 7
• For severe disease with risk of Pseudomonas: Levofloxacin or moxifloxacin 2, 8

Target Pathogens:

• Haemophilus influenzae (25-50% produce β-lactamase, making simple amoxicillin ineffective) 2, 8
• Streptococcus pneumoniae 3, 8
• Moraxella catarrhalis (50-70% produce β-lactamase) 2, 8

Critical Red Flags Requiring Reassessment

Before diagnosing acute bronchitis, rule out pneumonia if ANY of the following are present:

• Heart rate >100 beats/min 2
• Respiratory rate >24 breaths/min 2
• Oral temperature >38°C 2
• Focal consolidation findings on lung examination (rales, egophony, tactile fremitus) 2

If these are present, obtain chest radiography—this is pneumonia, not bronchitis, and requires different management. 2

When to Reassess or Escalate

Instruct patients to return if:

• Fever persists >3 days (suggests bacterial superinfection or pneumonia, not simple viral bronchitis) 2, 3
• Cough persists >3 weeks (consider asthma, COPD, pertussis, or gastroesophageal reflux) 2
• Symptoms worsen rather than gradually improve 2

Exception: Pertussis (Whooping Cough)

For confirmed or suspected pertussis, prescribe a macrolide antibiotic immediately:

• Azithromycin 500 mg day 1, then 250 mg daily for 4 days 2, 6
• Alternative: Erythromycin 2
• Isolate patient for 5 days from start of treatment 2
• Early treatment (within first few weeks) diminishes coughing paroxysms and prevents disease spread 2

Common Pitfalls to Avoid

• Do NOT prescribe antibiotics based on sputum color or purulence alone—this occurs in viral infections 2, 3
• Do NOT prescribe antibiotics based on cough duration alone—viral bronchitis cough lasts 10-14 days normally 2
• Do NOT use simple amoxicillin for complicated COPD—up to 25% of H. influenzae and 50-70% of M. catarrhalis produce β-lactamase 2
• Do NOT use fluoroquinolones as first-line therapy unless patient has severe COPD, risk factors for Pseudomonas, or treatment failure 2, 8
• Do NOT assume bacterial infection before the 3-day fever threshold—most cases are viral 2

Patient Education Strategy

Explain to patients:

• The condition is self-limiting and resolves within 3 weeks 2
• Antibiotics expose them to adverse effects (diarrhea, nausea, rash) without providing benefit in uncomplicated cases 2, 6
• Referring to the condition as a "chest cold" rather than "bronchitis" reduces antibiotic expectations 2
• Patient satisfaction depends more on physician-patient communication than whether an antibiotic is prescribed 2