What is the recommended antibiotic treatment for an otherwise healthy adult with acute bronchitis?

Antibiotics Should NOT Be Prescribed for Acute Bronchitis in Otherwise Healthy Adults

Antibiotics are not recommended for acute uncomplicated bronchitis in otherwise healthy adults, as this condition is viral in 89-95% of cases and antibiotics provide minimal benefit (reducing cough by only half a day) while causing significant adverse effects and promoting antibiotic resistance. 1, 2

Initial Assessment: Rule Out Pneumonia First

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

• Heart rate >100 beats/min - suggests pneumonia, not bronchitis
• Respiratory rate >24 breaths/min - suggests pneumonia, not bronchitis
• Oral temperature >38°C - suggests pneumonia, not bronchitis
• Abnormal chest examination findings (rales, egophony, tactile fremitus, focal consolidation) - suggests pneumonia, not bronchitis

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

Why Antibiotics Don't Work

The evidence against antibiotics is compelling 1, 3:

• Respiratory viruses cause 89-95% of cases - making antibiotics completely ineffective regardless of which agent you choose 1
• Minimal clinical benefit - antibiotics reduce cough duration by only 0.5 days (approximately 12 hours) 1, 3
• Significant harm - antibiotics significantly increase adverse events (RR 1.20; 95% CI 1.05-1.36) 1
• No difference in clinical outcomes between antibiotic and placebo groups for days of purulent sputum, days lost from work, or overall symptom resolution 3

Common Pitfalls to Avoid

Do NOT prescribe antibiotics based on these misleading clinical features 1, 2:

• Purulent sputum or sputum color change - occurs in 89-95% of viral bronchitis cases and does NOT indicate bacterial infection 1
• Duration of cough - viral bronchitis cough typically lasts 10-14 days, sometimes up to 3 weeks 1, 2
• Patient expectation for antibiotics - satisfaction depends more on physician-patient communication than whether an antibiotic is prescribed 1
• Initial fever in first 1-3 days - consistent with viral bronchitis and does NOT automatically indicate bacterial infection 2

What TO Do: Appropriate Management

Patient education and symptomatic treatment are the cornerstones of management 1, 4:

• 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 the risks of unnecessary antibiotic use, including side effects and contribution to antibiotic resistance 1
• Consider referring to the condition as a "chest cold" rather than bronchitis to reduce patient expectation for antibiotics 1

Symptomatic treatment options 1, 4:

• Codeine or dextromethorphan may provide modest effects on severity and duration of cough, particularly when dry cough is bothersome and disturbs sleep 1, 2
• β2-agonist bronchodilators (albuterol) should ONLY be used in select adult patients with accompanying wheezing - not routinely 1, 4
• Low-risk measures include elimination of environmental cough triggers and vaporized air treatments 1

What NOT to prescribe 1:

• NSAIDs at anti-inflammatory doses 5, 1
• Systemic corticosteroids 5, 1
• Expectorants or mucolytics 1
• Antihistamines 1
• Inhaled corticosteroids 1

The ONE Exception: Pertussis (Whooping Cough)

For confirmed or suspected pertussis, prescribe a macrolide antibiotic immediately 1, 2, 4:

• Erythromycin or azithromycin should be prescribed 1, 4
• Isolate patients 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

When to Reassess

Instruct patients to return if 1, 2:

• Fever persists >3 days - strongly suggests bacterial superinfection or pneumonia rather than simple viral bronchitis 5, 1, 2
• Cough persists >3 weeks - consider other diagnoses such as asthma, COPD, pertussis, or gastroesophageal reflux 1
• Symptoms worsen rather than gradually improve 1, 2

High-Risk Patients: A Different Approach

These guidelines apply to otherwise healthy adults. For high-risk patients with significant comorbidities, a different approach may be warranted 1, 2:

High-risk features include 1, 2:

• Age >75 years with cardiac failure, insulin-dependent diabetes, or serious neurological disorders
• Immunosuppression
• Chronic respiratory insufficiency or COPD with FEV1 <35%

For high-risk patients, consider antibiotics if 5, 2:

• Fever persists >3 days 5, 2
• At least 2 of 3 Anthonisen criteria are present: increased dyspnea, increased sputum volume, or increased sputum purulence 1

If antibiotics are indicated in high-risk patients 2:

• Amoxicillin 500 mg three times daily for 5-8 days 2
• Doxycycline 100 mg twice daily for 5-8 days (alternative) 2

Chronic Bronchitis/COPD Exacerbations

These are NOT the same as acute bronchitis in healthy adults 1, 4:

• For acute exacerbations of chronic bronchitis, prescribe antibiotics if the patient has chronic respiratory insufficiency (dyspnea at rest and/or FEV1 <35% and hypoxemia with PaO2 <60 mmHg) 5
• Consider antibiotics if at least 2 of 3 Anthonisen criteria are present AND the patient has risk factors 1