When should antibiotics be prescribed for a patient with acute bronchitis, considering factors such as underlying conditions like Chronic Obstructive Pulmonary Disease (COPD) or asthma, age, and symptoms?

When to Prescribe Antibiotics for Acute Bronchitis

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

Initial Assessment: Rule Out Pneumonia First

Before diagnosing acute bronchitis, you must exclude pneumonia by checking for these four criteria: 1, 2

• Heart rate >100 beats/min
• Respiratory rate >24 breaths/min
• Oral body temperature >38°C
• Focal chest examination findings (consolidation, egophony, or fremitus)

If ANY of these are present, obtain a chest radiograph to rule out pneumonia rather than treating as simple bronchitis. 1, 2

The Evidence Against Routine Antibiotic Use

• Respiratory viruses cause 89-95% of acute bronchitis cases, making antibiotics completely ineffective regardless of which one you choose. 2
• Purulent sputum does NOT indicate bacterial infection—it occurs in 89-95% of viral bronchitis cases and is not an indication for antibiotics. 1, 2
• Cough duration does NOT indicate bacterial infection—viral bronchitis cough typically lasts 10-14 days, sometimes up to 3 weeks. 1, 2
• Antibiotics reduce cough duration by only approximately 0.5 days (12 hours) while significantly increasing adverse events. 1, 2

Exceptions: When Antibiotics ARE Indicated

1. Confirmed or Suspected Pertussis (Whooping Cough)

• Prescribe a macrolide antibiotic (erythromycin or azithromycin) immediately. 1, 2
• Isolate the patient for 5 days from the start of treatment. 1, 2
• Early treatment within the first few weeks diminishes coughing paroxysms and prevents disease spread. 1, 2

2. COPD Exacerbations with Bacterial Signs

Prescribe antibiotics for 5 days when managing patients with COPD exacerbations who have clinical signs of bacterial infection, specifically: 1

• Increased sputum purulence PLUS
• Increased dyspnea and/or increased sputum volume

Appropriate antibiotics include aminopenicillin with clavulanic acid, a macrolide, or a tetracycline targeting Haemophilus influenzae, Streptococcus pneumoniae, and Moraxella catarrhalis. 1

3. High-Risk Elderly Patients with Specific Comorbidities

Consider antibiotics in patients ≥75 years old with: 2, 3

• Cardiac failure
• Insulin-dependent diabetes
• Serious neurological disorders
• Immunosuppression

AND who meet bacterial infection criteria (fever >38°C persisting >3 days, or increased sputum purulence with increased dyspnea/volume). 2, 3

Critical Pitfalls to Avoid

• Do NOT prescribe antibiotics based on sputum color alone—purulent sputum occurs in 89-95% of viral cases. 1, 2
• Do NOT prescribe antibiotics based on cough duration alone—viral bronchitis cough normally lasts 10-14 days. 1, 2
• Do NOT assume bacterial infection before the 3-day fever threshold—most cases are viral. 2
• Do NOT diagnose "recurrent acute bronchitis" without ruling out asthma or COPD—approximately one-third of these patients actually have undiagnosed asthma. 1, 2

Patient Education and Management

• Inform patients that cough typically lasts 10-14 days after the visit, even without antibiotics, and may persist up to 3 weeks. 1, 2
• Explain that patient satisfaction depends more on physician-patient communication than whether an antibiotic is prescribed. 2, 3
• Discuss the risks of unnecessary antibiotic use, including adverse effects and contribution to antibiotic resistance. 1, 2
• Refer to the condition as a "chest cold" rather than bronchitis to reduce patient expectation for antibiotics. 2

Symptomatic Treatment Options

• β2-agonist bronchodilators may be useful only in select adult patients with wheezing accompanying the cough. 1, 2
• Codeine or dextromethorphan may provide modest effects on severity and duration of cough, particularly when dry cough is bothersome and disturbs sleep. 1, 2
• Elimination of environmental cough triggers and vaporized air treatments are reasonable low-risk options. 1, 2

When to Reassess

Instruct patients to return if: 2

• Fever persists >3 days (suggests bacterial superinfection or pneumonia)
• Cough persists >3 weeks (consider other diagnoses: asthma, COPD, pertussis, GERD)
• Symptoms worsen rather than gradually improve