When should antibiotics be prescribed for acute bronchitis?

When to Give Antibiotics for Bronchitis

Antibiotics should NOT be prescribed for acute uncomplicated bronchitis in otherwise healthy adults, regardless of cough duration, sputum color, or patient expectations, because respiratory viruses cause 89-95% of cases and antibiotics provide no meaningful clinical benefit while causing significant harm. 1

Evidence Against Routine Antibiotic Use

The case against antibiotics in acute bronchitis is overwhelming:

• Antibiotics shorten cough by only 0.5 days (approximately 12 hours) while significantly increasing adverse events (RR 1.20; 95% CI 1.05-1.36) 1
• Respiratory viruses cause 89-95% of acute bronchitis cases, making antibiotics completely ineffective against the underlying pathogen 1, 2
• Multiple high-quality meta-analyses show no difference in clinical improvement between antibiotic and placebo groups (RR 1.07; 95% CI 0.99-1.15) 1
• The FDA removed uncomplicated acute bronchitis from approved antimicrobial indications in 1998 due to lack of efficacy 1

Critical Diagnostic Pitfalls to Avoid

Do NOT use these as justifications for antibiotics:

• Purulent (green/yellow) sputum occurs in 89-95% of VIRAL bronchitis and does not indicate bacterial infection—it reflects inflammatory cells, not bacteria 1, 2
• Cough duration is not a marker of bacterial infection—viral bronchitis cough typically lasts 10-14 days and may persist up to 3 weeks 1, 3
• Presence of fever in the first 1-3 days does not indicate bacterial infection 4

Exclude Pneumonia First

Before diagnosing acute bronchitis, rule out pneumonia by checking for ALL of the following 1, 3:

• Heart rate >100 beats/min
• Respiratory rate >24 breaths/min
• Oral temperature >38°C
• Abnormal chest examination findings (rales, egophony, tactile fremitus)

If ANY of these are present, obtain chest radiography to rule out pneumonia rather than treating as simple bronchitis 1, 3, 4

The ONE Exception: Pertussis

If pertussis (whooping cough) is confirmed or strongly suspected, prescribe a macrolide antibiotic (azithromycin or erythromycin) immediately 1, 3:

• Isolate the patient for 5 days from treatment start 3
• Early treatment (within first few weeks) diminishes coughing paroxysms and prevents disease spread 1, 3
• Suspect pertussis with: paroxysmal cough, post-tussive vomiting, inspiratory "whoop," or cough >2 weeks 3

Special Population: COPD Exacerbations

For patients with known COPD experiencing an acute exacerbation, antibiotics ARE indicated when there are clinical signs of bacterial infection 1:

• Presence of increased sputum purulence PLUS at least one of:
  • Increased dyspnea
  • Increased sputum volume
• Limit antibiotic duration to 5 days for COPD exacerbations 1
• Appropriate antibiotics include aminopenicillin with clavulanic acid, macrolide, or tetracycline 1

Important distinction: These recommendations apply to patients with established chronic bronchitis/COPD, NOT otherwise healthy adults with acute bronchitis 1, 3

When to Reassess (Red Flags)

Instruct patients to return if 3, 4:

• Fever persists >3 days (suggests possible bacterial superinfection or pneumonia)
• Cough persists >3 weeks (consider asthma, COPD, pertussis, GERD, or upper airway cough syndrome)
• Symptoms worsen rather than gradually improve

Symptomatic Management

Recommended measures 1, 3:

• Antitussives (codeine or dextromethorphan) for bothersome dry cough, especially if disrupting sleep
• Short-acting β₂-agonists (albuterol) ONLY for patients with wheezing accompanying the cough
• Environmental measures: remove irritants (dust, dander) and use humidified air

NOT recommended (no consistent benefit) 3:

• Expectorants, mucolytics, antihistamines
• Inhaled or oral corticosteroids
• NSAIDs at anti-inflammatory doses

Patient Communication Strategy

Physician-patient communication has greater impact on satisfaction than whether an antibiotic is prescribed 1, 3. Key points to discuss:

• Cough typically lasts 10-14 days and may persist up to 3 weeks even without antibiotics 1, 3
• Antibiotics do not shorten the illness and expose patients to adverse effects (diarrhea, rash, yeast infections, rare anaphylaxis) 1, 3
• Antibiotics promote resistance, making future infections harder to treat 1, 3
• Referring to the illness as a "chest cold" rather than "bronchitis" reduces antibiotic expectations 3

High-Risk Populations Requiring Different Approach

These guidelines apply ONLY to otherwise healthy adults. Patients with the following conditions may require antibiotics and individualized management 1, 3, 4:

• COPD or chronic bronchitis with respiratory insufficiency
• Heart failure
• Immunosuppression
• Age >75 years with significant comorbidities (cardiac failure, insulin-dependent diabetes, serious neurological disorders)
• Complicated anatomy (bronchiectasis)
• Recent history of resistant bacterial infections