For an otherwise healthy adult with uncomplicated acute bronchitis, which is the preferred first‑line antibiotic, amoxicillin‑clavulanate (Augmentin) or azithromycin?

Antibiotics Should Not Be Prescribed for Uncomplicated Acute Bronchitis

For an otherwise healthy adult with uncomplicated acute bronchitis, neither amoxicillin-clavulanate (Augmentin) nor azithromycin should be prescribed, as antibiotics provide no meaningful clinical benefit while exposing patients to adverse effects and contributing to antimicrobial resistance. 1, 2

Why Antibiotics Are Not Indicated

Viral Etiology Dominates

• Respiratory viruses cause 89–95% of acute bronchitis cases in otherwise healthy adults, making antibiotics completely ineffective against the underlying pathogen. 1, 2
• Only 5–10% of cases involve bacterial pathogens such as Mycoplasma pneumoniae, Chlamydophila pneumoniae, or Bordetella pertussis—and even these atypical bacteria often resolve without antibiotics. 2

Minimal Clinical Benefit

• Multiple systematic reviews demonstrate that antibiotics reduce cough duration by only approximately 0.5 days (12 hours), which is not clinically meaningful. 1, 2
• Meta-analyses show no significant difference in clinical improvement between antibiotic and placebo groups (RR 1.07; 95% CI 0.99–1.15). 1, 2

Increased Adverse Events

• Antibiotics significantly increase adverse events compared to placebo (RR 1.20; 95% CI 1.05–1.36), including diarrhea, rash, nausea, and yeast infections. 1, 2
• Adverse events occur in 16% of antibiotic-treated patients versus 11% with placebo. 2

Common Diagnostic Pitfalls to Avoid

Purulent Sputum Does Not Indicate Bacterial Infection

• Green or yellow sputum is present in 89–95% of viral bronchitis cases and reflects inflammatory cells or sloughed epithelial cells, not bacterial proliferation. 1, 2
• Sputum color or purulence should never be used as justification for antibiotic therapy. 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 even without treatment. 1, 2
• Cough duration alone does not justify antibiotic prescription. 1, 2

Rule Out Pneumonia First

• Before diagnosing acute bronchitis, check vital signs and perform a focused lung examination. 1, 3
• If any of the following are present, obtain a chest radiograph to exclude pneumonia: heart rate >100 bpm, respiratory rate >24 breaths/min, oral temperature >38°C, or abnormal chest findings (crackles, egophony, increased tactile fremitus). 1, 3

The One Exception: Pertussis

• When pertussis (whooping cough) is confirmed or strongly suspected (paroxysmal cough, post-tussive vomiting, inspiratory "whoop," cough >2 weeks), prescribe a macrolide antibiotic such as azithromycin or erythromycin immediately. 1, 2
• Isolate the patient for 5 days from the start of treatment to prevent disease spread. 1, 2
• Early macrolide therapy reduces cough paroxysms and limits transmission. 1, 2

Appropriate Management of Uncomplicated Acute Bronchitis

Patient Education (Most Important)

• Inform patients that cough typically lasts 10–14 days and may persist up to 3 weeks, even without antibiotics. 1, 2
• Explain that antibiotics provide no clinical benefit while causing adverse effects and promoting antimicrobial resistance. 1, 2
• Emphasize that patient satisfaction depends more on physician-patient communication than whether an antibiotic is prescribed. 1, 2
• Consider referring to the illness as a "chest cold" rather than "bronchitis" to reduce antibiotic expectations. 1, 2

Symptomatic Treatment

• For bothersome dry cough (especially nocturnal), offer codeine or dextromethorphan for modest symptomatic relief. 1, 2
• Use short-acting β₂-agonists (e.g., albuterol) only in patients with documented wheezing accompanying the cough. 1, 3
• Recommend environmental measures: removal of irritants (dust, allergens) and humidification of indoor air. 1, 2

When to Reassess

• Advise return if fever persists >3 days, suggesting possible bacterial superinfection or pneumonia. 1, 2
• Advise return if cough persists >3 weeks, warranting evaluation for asthma, COPD, pertussis, or gastroesophageal reflux. 1, 2
• Advise return if symptoms worsen rather than gradually improve. 1, 2

Why Neither Augmentin Nor Azithromycin Should Be Chosen

Both Are Ineffective for Viral Bronchitis

• Since 89–95% of cases are viral, neither amoxicillin-clavulanate nor azithromycin can target the underlying cause. 1, 2
• The question itself contains a false premise—the correct answer is to prescribe neither antibiotic. 1, 2

Comparative Evidence Shows No Advantage

• A randomized trial comparing amoxicillin-clavulanate to placebo showed no significant difference in time to cough resolution in acute bronchitis. 1
• Macrolides such as azithromycin caused significantly more adverse events than placebo in acute bronchitis patients. 1
• A comparative study of azithromycin versus amoxicillin-clavulanate in lower respiratory tract infections showed similar efficacy, but this was in the context of acute exacerbations of chronic bronchitis—not uncomplicated acute bronchitis in otherwise healthy adults. 4

Antibiotic Stewardship Concerns

• The WHO Essential Medicines guidelines specifically state that antibiotics should not be recommended for acute bronchitis in otherwise healthy people. 2
• The FDA removed uncomplicated acute bronchitis from the list of approved antimicrobial indications in 1998 due to lack of efficacy. 1

Special Populations (Outside Scope of This Recommendation)

• These recommendations apply only to otherwise healthy adults without underlying lung disease. 1, 2
• Patients with COPD, chronic bronchitis, heart failure, immunosuppression, or age >75 years with comorbidities may require individualized management, including possible antibiotic therapy. 1, 2
• For acute exacerbations of chronic bronchitis in patients with COPD, antibiotics may be indicated when at least two of the three Anthonisen criteria are met (increased dyspnea, increased sputum volume, increased sputum purulence). 1, 5